Vaccine Preventable Disease: Surveillance Report to December 31, 2019

List of figures and tables

Abbreviations

AFP
Acute flaccid paralysis
AFM
Acute flaccid myelitis
CAFPSS
Canadian Acute Flaccid Paralysis Surveillance System
CIRID
Centre for Immunization and Respiratory Infectious Diseases
CMRSS
Canadian Measles and Rubella Surveillance System
cNICS
Childhood National Immunization Coverage Survey
CNDSS
Canadian Notifiable Disease Surveillance System
CPS
Canadian Pediatric Society
CRI
Congenital rubella infection
CRS
Congenital rubella syndrome
eIMDSS
Enhanced Invasive Meningococcal Disease Surveillance System
Hib
Haemophilus influenzae type b
IMD
Invasive meningococcal disease
IMPACT
Immunization Monitoring Program ACTive
IPD
Invasive pneumococcal disease
IPV
Inactivated poliomyelitis vaccine
NACI
National Advisory Committee on Immunization
OPV
Oral polio vaccine
NML
National Microbiology Laboratory
PAHO
Pan-American Health Organization
PHAC
Public Health Agency of Canada
Tdap
Tetanus, diphtheria, pertussis vaccine
VPDs
Vaccine preventable diseases
WHO
World Health Organization
WPV
Wild-type poliovirus

Executive summary

Introduction

Disease prevention is a core function of public health. Many common infectious diseases that were once a major cause of morbidity and mortality in Canada are now preventable with vaccines. Nevertheless, vaccine preventable diseases (VPDs) remain a public health concern in Canada, and it is important to achieve the highest possible levels of vaccination. As part of the National Immunization Strategy for 2016-2021, vaccine coverage goals and VPD reduction targets by 2025 were set. The Vaccine Preventable Disease in Canada: Surveillance Report to December 31, 2019 summarizes the overall trends of 12 nationally notifiable VPDs for which publicly-funded routine vaccination programs are in place in all provinces and territories with a focus on the epidemiology of the VPDs for the most recent five-year period (2015 to 2019). This report supports the Government of Canada's international commitment to report on disease elimination and eradication initiatives and it provides evidence to inform vaccination programs and policy.

Consistent with the structure of the VPD Reduction Targets by 2025, each VPD was placed into one of three categories: VPDs under elimination in CanadaFootnote 1, VPDs with low-level incidenceFootnote 2, and VPDs with moderate-level incidenceFootnote 3. The findings for each of these categories are summarized below.

Key findings

VPDs under elimination Footnote a

Canada has maintained elimination status for measles, rubella, congenital rubella syndrome/congenital rubella infection (CRS/CRI), and polio. Based on surveillance data from 2015 to 2019, there were zero endemic cases of measles and rubella, along with zero cases of CRS/CRI and polio, resulting in Canada being on track to meet national VPD reduction targets for these diseases by 2025. Although vaccination coverage rates were fairly high among children two years of age for measles (90%), rubella (89%) and polio (92%), they remained below the 95% national vaccine coverage goal for these diseases.

VPDs with low-level incidenceFootnote b

Based on surveillance data from 2015 to 2019, Canada is on track to meet national VPD reduction targets by 2025 for tetanus, invasive disease due to Haemophilus influenza serotype b (Hib) and invasive meningococcal disease (IMD) but not currently on track to meet the reduction target for mumps if large outbreaks continue to occur. Surveillance data is not currently available to assess progress in meeting national VPD reduction targets for respiratory diphtheria and maternal and neonatal tetanus. However, work is currently underway to estimate maternal and neonatal tetanus case counts at the national level.

Despite these low disease incidence rates, vaccine coverage rates can be improved. Rates for diphtheria (78%), tetanus (78%), Hib (74%), mumps (89%), and meningococcal C vaccine (91%) by two years of age were all below the national vaccine coverage goal of 95% for each of these diseases.

VPDs with moderate-level incidenceFootnote c

Based on surveillance data from 2015 to 2019, Canada is on track to meet the VPD reduction targets for pertussis and varicella by 2025, but not for IPD, as incidence rates in adults 65 years of age and older have not decreased by 5%. Note, however, that varicella is not reportable in all provinces and territories and there are cases that may not have been seen by a physician or have not been laboratory confirmed.

Vaccine coverage rates for pertussis (78%), IPD (84%), varicella (83%) by two years of age were all below the national vaccine coverage goal of 95% for each of these diseases. Furthermore, the vaccine coverage rate for IPD for individuals 65 years of age and older is 58%, far below the 80% coverage goal.

Concluding remarks

The findings of this report underscore the pivotal role of publicly-funded infant and childhood vaccination programs in reducing the burden of VPDs. For most VPDs, incidence rates in Canada have declined drastically since the pre-vaccine era. There is a pressing need to enhance vaccine coverage in the next few years for Canada to meet the reduction targets by 2025 and reduce the burden of VPDs in Canada.

Introduction

Vaccines are one of the greatest achievements in public health and are considered to have saved more lives in the past 50 years in Canada than any other health intervention Footnote 1,Footnote 2,Footnote 3. While infectious diseases were the leading cause of death in Canada and worldwide during the 1900s, they are now responsible for less than 5% of all deaths in Canada, thanks in part to publicly-funded vaccination programs Footnote 1,Footnote 4,Footnote 5. Furthermore, Canada has contributed to the global eradication of smallpox as well as the elimination of endemically transmitted poliomyelitis (1994), measles (1998), rubella (2005) and CRS/CRI (2000) in the Americas through strong public health initiatives, including surveillance activities and routine publicly-funded vaccination programs Footnote 4, Footnote 5,Footnote 6. As part of Canada's National Immunization Strategy for 2016-2021, vaccine coverage goals and vaccine preventable disease (VPD) reduction targets by 2025 were set in collaboration with provinces and territories and are based on international standards and best practices Footnote 7.

Despite these successes, VPDs remain a public health concern in Canada. While vaccination coverage rates are good, Canada has yet to meet most national vaccination coverage goals. Despite low rates of disease, VPDs are a considerable health burden to the population, with infections causing a variety of serious complications such as pneumonia, meningitis, encephalitis, amputations, and death. Infections due to VPDs also have substantial economic and societal costs related to missed school and work days, health care provider visits, hospitalization and rehabilitation Footnote 2,Footnote 3. Finally, despite attaining elimination status for several VPDs, the risk of an importation and possible resurgence of any of the VPDs under elimination exists so long as these diseases continue to occur in countries outside of the Americas and vaccination coverage remains suboptimal. Therefore, vaccination rates should be improved to ensure herd immunity. Moreover, surveillance and prevention of VPDs are essential to protect population health and maintain successes in health achievement.

The prevention and control of VPDs is a shared responsibility in Canada. At the federal level, the Public Health Agency of Canada (PHAC) conducts national surveillance of VPDs; provides leadership and coordination for the National Immunization Strategy; delivers public and professional education and outreach to promote vaccination acceptance and uptake; and ensures the security of vaccine supply. The National Advisory Committee on Immunization (NACI) makes recommendations for the use of vaccines in Canada. Provincial and territorial public health authorities are responsible for vaccination program decisions and implementing programs that meet their goals, policies, and strategies in light of their specific epidemiologic and financial circumstances.

The VPD national surveillance report is published biennially, with the first report published in 2017 and the second in 2019.

Objective

This report provides a description of the epidemiology of 12 nationally notifiable VPDs for which publicly-funded routine vaccination programs exist in all Canadian provinces and territories, with a highlight of the data from 2015 to 2019. This report is intended to serve the following objectives:

Methods

The 12 VPDs are grouped according to their incidence levels in Canada.

Diseases under elimination: VPDs that have domestic and international programs to reduce their disease-specific incidence to zero

Endemic diseases with low-level incidence: VPDs that generally have an annual incidence rate of less than one case per 100,000 population

Endemic disease with moderate–levels of incidence: VPDs that consistently have an annual incidence rate equal to or greater than one case per 100,000 population

A description of this report's data sources, types of analyses conducted, and data limitations are provided in Appendix A. In addition, the epidemiology of VPDs contained in this report should be interpreted with an awareness of available vaccination programs, populations eligible for vaccination, rates of vaccine uptake by the population, and vaccine effectiveness. Details pertaining to specific vaccines can be found in the Canadian Immunization Guide and National Advisory Committee on Immunization statements.

Only nationally notifiable VPDs are presented in this report, thus VPDs such as zoster, rotavirus gastroenteritis, and human papillomavirus infection are not included. Furthermore, information on the national epidemiology of influenza and hepatitis are covered in separate surveillance reports.

While this report presents an overview of VPDs in Canada, routine surveillance reports for many of the diseases included are published on a regular basis and are referenced throughout this report. Readers interested in more detailed data are encouraged to consult these publications.

Results

National surveillance data indicate that from 2015 to 2019, an average of 7,914 VPD cases were reported annually (Table 1) which represents an average annual crude incidence rate of 21.5 cases per 100,000 population (Table 2). The VPDs that accounted for the largest proportion of reported cases were IPD (45%) and pertussis (37%). Age groups most affected by VPDs included children less than one year of age (88.0 cases per 100,000 population), children one to four years of age (48.8 cases per 100,000 population), and children 10 to 14 years of age (40.3 cases per 100,000 population) (Figure 1). During the same period, case counts were highest among those 60 years of age and older (n=9,993 cases) and 40 to 59 years of age (n=7,621 cases). The most affected age groups varied by disease, with some diseases such as pertussis, varicella, and IMD having a greater incidence in young children, while incidence was highest in the elderly for IPD and in adolescents/young adults for mumps.

Figure 1: Total number and average incidence rates (per 100,000 population) of reported vaccine preventable disease cases in Canada by age group, 2015 to 2019 (n=39,546)Footnote d
Figure 1: Text equivalent
Total number and average incidence rates (per 100,000 population) of reported vaccine preventable disease cases in Canada by age group, 2015 to 2019 (n=39,546)
Age groups Total number of cases Overall incidence rate
(per 100,000 population)
<1 1,690 87.9
1 to 4 3,806 48.8
5 to 9 3,848 38.1
10 to 14 3,964 40.3
15 to 19 1,919 18.1
20 to 24 1,624 13.4
25 to 29 1,565 12.3
30 to 39 3,516 14.0
40 to 59 7,621 15.0
60+ 9,993 23.2
Table 1. Average annual reported cases and range of nationally notifiable vaccine preventable disease in Canada by age group, 2015 to 2019.
Age group (Years) Measles Rubella CRS/CRI Polio Tetanus Diphtheria Hib Mumps IMD Varicella IPD Pertussis Overall
< 1 4.2 (0-7) 0 0.2 (0-1) 0 0 0.2 (0-1) 3.2 (0-5) 3.6 (0-10) 12.2 (6-17) 26.6 (14-40) 53.6 (45-60) 234.2 (132-317) 338.2 (243 - 419)
1 to 4 8.0 (2-18) 0 N/A 0 0.2 (0-1) 0.4 (0-1) 2.8 (1-5) 18.6 (2-53) 12.8 (8-16) 45.8 (23-75) 180.8 (151-197) 491.8 (269-660) 761.2 (430 - 939)
5 to 9 11.6 (0-35) 0 0 0.2 (0-1) 1 (0-3) 0.4 (0-2) 41.2 (0-135) 2.6 (1-4) 68.4 (20-141) 73.2 (71-76) 571.0 (274-788) 769.6 (430 - 985)
10 to 14 14.6 (0-55) 0 0 0 0.6 (0-2) 0.2 (0-1) 52.0 (2-187) 2.6 (2-4) 83.6 (38-162) 23.8 (23-25) 615.2 (259-837) 792.8 (386 - 1009)
15 to 19 11.6 (0-39) 0 0 0 0 0.2 (0-1) 96.0 (16-311) 12.2 (10-15) 53.3 (35-78) 30.0 (25-36) 180.4 (79-247) 383.8 (239 - 622)
20 to 24 7.2 (1-15) 0 0 0.2 (0-1) 0.2 (0-1) 0 122.2 (11-335) 11 (6-19) 47.2 (32-68) 45.2 (35-54) 91.6 (44-130) 324.8 (221 - 545)
25 to 29 6.0 (0-11) 0 0 0.2 (0-1) 0.2 (0-1) 0.8 (0-2) 113.4 (9-352) 4.6 (2-10) 35.2 (31-38) 73.2 (64-93) 79.4 (45-112) 313.0 (212 - 560)
30 to 39 8.0 (0-14) 0 0 0.8 (0-2) 0.4 (0-1) 1.6 (0-3) 149.4 (5-482) 7.6 (5-11) 52.4 (34-63) 263.0 (216-312) 220.0 (114-307) 703.2 (574 - 1057)
40 to 59 7.2 (1-16) 0.4 (0-1) 0 1.0 (0-2) 1.4 (0-3) 3.0 (0-7) 123.2 (9-363) 20.0 (13-33) 43.6 (38-58) 986.2 (909-1163) 338.2 (174-442) 1524.2 (1392 - 1746)
≥ 60 0.4 (0-2) 0 0 0.8 (0-2) 0.6 (0-1) 3.8 (1-5) 14.4 (2-38) 35.2 (26-45) 16.8 (12-20) 1820.8 (1638-2065) 105.8 (54-137) 1998.6 (1809 - 1809)
Unspecified 0 0 0 0 0 0 0 0.2 (0-1) 0.4 (0-1) 2.8 (0-13) 1.6 (0-4) 5.0 (0 - 13)
All ages 78.8 (11-196) 0.4 (0-1) 0 3.6 (1-5) 5.0 (1-10) 16 (11-27) 733.4 (59-2266) 121.0 (99-141) 473.2 (311-695) 3552.6 (3211-4026) 2929.2 (1467-3951) 7914.0 (6775 - 9837)
Table 2. Average annual incidence rates (cases per 100,000 population) and range of nationally notifiable vaccine preventable diseases in Canada by age group, 2015 to 2019.
Age group (Years) Measles Rubella CRS/CRI Polio Tetanus Diphtheria Hib Mumps IMD Varicella IPD Pertussis Overall
< 1 1.1 (0-1.8) 0 0.1 (0-0.3) 0 0 0.1 (0.0-0.3) 0.8 (0.0-1.3) 0.9 (0.3-2.6) 3.2 (1.5-4.9) 6.9 (3.6-10.6) 13.9 (11.8-15.4) 60.7 (34.8-81.4) 87.9 (64.1 - 107.5)
1 to 4 0.5 (0.1-1.2) 0 N/A 0 <0.05 (0-0.1) <0.05 (0.0-0.1) 0.2 (0.1-0.3) 1.2 (0.1-3.4) 0.8 (0.5-1) 2.9 (1.5-4.8) 11.6 (9.7-12.6) 31.5 (17.2-42.3) 48.8 (33.8 - 60.2)
5 to 9 0.6 (0-1.8) 0 0 <0.05 (0-0.1) <0.05 (0.0-0.1) <0.05 (0-0.1) 2.0 (0-6.7) 0.1 (0.0-0.2) 3.4 (1.0-7.1) 3.6 (3.5-3.8) 28.4 (13.5-39.2) 38.1 (21.1 - 49.1)
10 to 14 0.8 (0-2.9) 0 0 0 <0.05 (0.0-0.1) <0.05 (0-0.1) 2.6 (0.1-9.5) 0.1 (0.1-0.2) 4.3 (1.9-8.5) 1.2 (1.1-1.2) 31.5 (12.9-43.3) 40.3 (19.3 - 52.4)
15 to 19 0.5 (0-1.9) 0 0 <0.05 (0-0.0) 0 <0.05 (0-0.0) 4.5 (0.7-14.7) 0.6 (0.5-0.7) 2.5 (1.6-3.7) 1.4 (1.2-1.7) 8.5 (3.7-11.7) 18.1 (11.2 - 29.4)
20 to 24 0.3 (0.0-0.6) 0 0 <0.05 (0-0.0) <0.05 (0.0-0.0) 0 5.0 (0.5-13.9) 0.5 (0.3-0.8) 1.9 (1.3-2.7) 1.9 (1.5-2.3) 3.8 (1.8-5.4) 13.4 (8.9 - 22.6)
25 to 29 0.2 (0-0.4) 0 0 <0.05 (0-0.0) <0.05 (0.0-0.0) <0.05 (0-0.1) 4.5 (0.4-13.9) 0.2 (0.1-0.4) 1.4 (1.3-1.5) 2.9 (2.6-3.6) 3.2 (1.7-4.5) 12.3 (8.0 - 22.1)
30 to 39 0.2 (0-0.3) 0 0 <0.05 (0-0.0) <0.05 (0.0-0.0) <0.05 (0.0-0.1) 3.0 (0.4-9.6) 0.1 (0.1-0.2) 1.0 (0.7-1.3) 5.2 (4.5-6.0) 4.4 (2.2-6.2) 14.0 (11.4 - 21.1)
40 to 59 0.1 (0.0-0.2) <0.05 (0-0.0) 0 <0.05 (0-0.0) <0.05 (0.0-0.0) <0.05 (0-0.1) 1.2 (0.1-3.6) 0.2 (0.1-0.3) 0.4 (0.4-0.6) 9.7 (8.9-11.5) 3.3 (1.7-4.3) 15.0 (13.8 - 17.2)
≥ 60 <0.05 (0-0.0) 0 0 <0.05 (0-0.0) <0.05 (0.0-0.0) <0.05 (0.0-0.1) 0.2 (0-0.4) 0.4 (0.3-0.5) 0.2 (0.1-0.2) 21.1 (19.8-23.2) 1.2 (0.6-1.6) 23.2 (22.3 - 24.7)
Unspecified 0 0 0 0 0 No data No data No data No data No data No data No data
All ages 0.2 (0.0-0.5) <0.05 (0.0-0.0) 0 <0.05 (0.0-0.0) <0.05 (0.0-0.0) <0.05 (0.0-0.1) 2.0 (0.2-6.2) 0.3 (0.3-0.4) 2.0 (0.9-3.5) 9.7 (9.0-10.8) 8.0 (3.9-10.9) 21.5 (17.9 - 26.8)

Note: For summary purposes, incidence rates are indicated with one decimal. Therefore, when incidence rates are lower than 0.05 per 100,000 population, it is indicated as such. Incidence rates for all ages are detailed in each VPD section.

Vaccine preventable diseases under elimination in Canada

Measles

Key points:

A measles-containing vaccine was made available in Canada in 1963 and routine vaccination programs were in place in all provinces and territories by 1970 Footnote 8,Footnote 9. In 1996/1997, all provinces and territories added a second dose of measles-containing vaccine to their routine schedules Footnote 10. Before measles-containing vaccine became available, many thousands of measles cases were reported annually and large outbreaks occurred in two to five-year cycles. With routine vaccination, the incidence of measles has declined by over 99% from an average incidence rate of 373.3 cases per 100,000 population in the pre-vaccine era (1950 to 1954)Footnote e to 0.2 cases per 100,000 population from 2015 to 2019 (Figure 2). Nonetheless, imported cases continue to occur in Canada and have resulted in secondary spread and measles outbreaks. For updated information on measles activities in Canada, refer to Measles and Rubella Weekly Reports and for more information in the Americas, refer to the PAHO Epidemiological Alerts and Updates.

Figure 2: Number and incidence rates (per 100,000 population) of reported measles cases in Canada by year, 1950 to 2019Footnote f
Figure 2: Text equivalent
Number and incidence rates (per 100,000 population) of reported measles cases in Canada by year, 1950 to 2019
Year Cases Incidence rate
(per 100,000 population)
1950 55,653 406.6
1951 61,370 438.8
1952 56,178 389.2
1953 57,871 390.5
1954 36,850 241.5
1955 56,922 363.3
1956 53,986 348.1
1957 49,712 330.3
1958 35,531 229.3
1959 No data No data
1960 No data No data
1961 No data No data
1962 No data No data
1963 No data No data
1964 No data No data
1965 No data No data
1966 No data No data
1967 No data No data
1968 No data No data
1969 11,720 64.4
1970 25,137 136.4
1971 7,439 33.8
1972 3,136 14.1
1973 10,911 48.3
1974 11,985 52.3
1975 13,143 56.6
1976 9,158 38.9
1977 8,832 37.1
1978 5,858 24.4
1979 22,444 92.4
1980 13,864 56.3
1981 2,307 9.3
1982 1,064 4.2
1983 934 3.7
1984 4,086 15.9
1985 2,899 11.2
1986 15,796 60.3
1987 3,065 11.5
1988 710 2.6
1989 21,523 78.5
1990 1,738 6.3
1991 6,151 21.9
1992 2,915 10.2
1993 192 0.7
1994 517 1.8
1995 2,366 8.0
1996 328 1.1
1997 531 1.8
1998 17 0.1
1999 32 0.1
2000 207 0.7
2001 38 0.1
2002 9 <0.1
2003 17 0.1
2004 9 <0.1
2005 8 <0.1
2006 13 <0.1
2007 101 0.3
2008 61 0.2
2009 14 <0.1
2010 99 0.3
2011 752 2.2
2012 10 <0.1
2013 83 0.2
2014 418 1.2
2015 196 0.5
2016 11 <0.1
2017 45 0.1
2018 29 0.1
2019 113 0.3

Epidemiology between 2015 and 2019

From 2015 to 2019, a total of 394 measles cases were reported in Canada through the Canadian Measles and Rubella Surveillance System. An average of 79 cases per year (range: 11 to 196) was reported, with the average incidence rate of 0.22 case per 100,000 population (range: 0.03 to 0.55) (Figure 2). Of these cases, 88 (22%) were imported to Canada and 278 (71%) were due to subsequent transmissions in Canada (i.e., were exposed in Canada and could be linked to a confirmed measles case). The source of infection (i.e., a link to another measles case) or location of exposure (i.e., acquired in Canada or abroad) could not be determined for 28 cases (7%). Sixty-four (16%) cases were hospitalized. Although cases were reported in every age group and the most affected age group varied from year to year depending on the outbreak context, for the period as a whole, the highest incidence rates were reported in infants under the age of one (1.1 cases per 100,000 population), followed by 10 to 14 years of age (0.7 cases per 100,000 population) (Figure 3). Cases were relatively evenly distributed between male and female.

Twenty-three outbreaks were reported during the surveillance period with the largest one reported in 2015. In this 2015 outbreak, the index case was exposed to measles during travel to a popular theme park in California. The outbreak resulted in 159 cases in Canada with most of the secondary transmission occurring in a non-immunizing religious community to which the index case belonged. Genotype B3 was associated with this outbreak. In 2017, a multi-jurisdictional outbreak was reported across Nova Scotia, Newfoundland and Labrador, Ontario, New Brunswick and Alberta. The outbreak resulted in 29 cases in a variety of settings including air travel/airport, healthcare, social, school and community settings. This outbreak provided the first evidence in Canada of measles transmission in domestic air travel. The genotype associated with this outbreak was D8. Based on the data for this period, Canada is on track to meet its VPD reduction target of zero endemic cases of measles by 2025. In June 2021, Canada re-certified its elimination status to measles, rubella and CRS for years 2016-2020.

Figure 3: Total number and overall incidence rates (per 100,000 population) of reported measles cases in Canada by age group, 2015 to 2019 (n=394)
Figure 3: Text equivalent
Total number and overall incidence rates (per 100,000 population) of reported measles cases in Canada by age group, 2015 to 2019 (n=394)
Age groups Total number of cases Incidence rate
(per 100,000 population)
< 1 21 1.1
1 to 4 40 0.5
5 to 9 58 0.6
10 to 14 73 0.7
15 to 19 58 0.6
20 to 24 36 0.3
25 to 29 30 0.2
30 to 39 40 0.2
40 to 59 36 0.1
≥ 60 2 <0.1

Measles vaccination coverage

Based on the 2019 cNICS, 90% of children in Canada received the recommended dose of measles-containing vaccine by two years of age and 83% received the recommended doses by seven years of age Footnote 11. This is below the 95% vaccination coverage goals for receiving one dose of a measles-containing vaccine by two years of age and two doses by seven years of age.

Further reading

Rubella

Key points:

A rubella-containing vaccine was made available in Canada in 1969 and routine vaccination programs were in place across all provinces and territories by 1983 Footnote 10,Footnote 12 . Before the rubella-containing vaccine became available, many thousands of rubella cases were reported annually and outbreaks occurred in three to six-year cycles. With routine vaccination, the incidence of rubella has declined by over 99% from an average incidence rate of 107.2 cases per 100,000 population in the pre-vaccine era (1950 to 1954)Footnote h to 0.001 cases per 100,000 population from 2015 to 2019 (Figure 4). Because imported cases continue to occur, there is still a risk of secondary spread to Canadians who remain vulnerable due to inadequate vaccination. Ongoing vigilance is required as a result. More recent data on rubella can be found in the Measles and Rubella Weekly Monitoring Reports.

Figure 4: Number and incidence rates (per 100,000 population) of reported rubella cases in Canada by year, 1950 to 2019Footnote i
Figure 4: Text equivalent
Number and incidence rates (per 100,000 population) of reported rubella cases in Canada by year, 1950 to 2019
Year Cases Incidence rate
(per 100,000 population)
1950 37,917 277.0
1951 12,624 93.7
1952 10,116 70.1
1953 9,745 65.8
1954 4,468 29.5
1955 20,409 131.1
1956 51,036 331.2
1957 16,652 110.6
1958 7,431 50.3
1959 No data No data
1960 No data No data
1961 No data No data
1962 No data No data
1963 No data No data
1964 No data No data
1965 No data No data
1966 No data No data
1967 No data No data
1968 No data No data
1969 8,934 47.4
1970 12,710 66.7
1971 12,567 57.5
1972 2,808 12.7
1973 3,189 14.3
1974 7,732 34.1
1975 12,032 52.3
1976 4,167 17.9
1977 2,159 9.1
1978 3,270 13.7
1979 8,201 33.9
1980 3,138 12.8
1981 1,719 6.9
1982 2,973 11.8
1983 7,420 29.2
1984 1,831 7.1
1985 2,989 11.5
1986 3,570 13.6
1987 1,634 6.2
1988 801 3.0
1989 2,440 8.9
1990 506 1.8
1991 765 2.7
1992 2,201 7.7
1993 1,018 3.5
1994 241 0.8
1995 287 1.0
1996 272 0.9
1997 4,003 13.3
1998 63 0.2
1999 24 0.1
2000 29 0.1
2001 27 0.1
2002 15 <0.1
2003 14 <0.1
2004 9 <0.1
2005 319 1.0
2006 9 <0.1
2007 8 <0.1
2008 5 <0.1
2009 7 <0.1
2010 13 <0.1
2011 2 <0.1
2012 2 <0.1
2013 1 <0.1
2014 1 <0.1
2015 0 <0.1
2016 1 <0.1
2017 0 <0.1
2018 0 <0.1
2019 1 <0.1

Epidemiology between 2015 and 2019

As rubella has been eliminated in Canada, disease activity generally results from imported cases. From 2015 to 2019, a total of two rubella cases were reported (Figure 4). The average incidence rate was 0.001 cases per 100,000 population for this period. Both cases were in adults between 40 and 59 years of age and neither of them were hospitalized. One case was imported and the other one had no recent travel history. Based on the data for this period, Canada is on track to meet its disease reduction target of zero endemic rubella cases by 2025.

Rubella vaccination coverage

Based on the 2019 cNICS, 89% of children in Canada received the recommended one dose of rubella-containing vaccine by two years of age, which falls below the 95% vaccine coverage goal. However, 96% received the recommended one dose by seven years of age, which meets the national coverage goal of 95% Footnote 11. In seroprevalence studies of cohorts of pregnant women in Canada, from 2006 to 2012, the percentage of study participants immune to rubella ranged from 84% to 92% Footnote 13,Footnote 14,Footnote 15.

Further reading

Congenital rubella syndrome (CRS) and congenital rubella infection (CRI)

Key points:

With routine rubella vaccination, CRS/CRI has declined by 98%. The average incidence rate of CRS/CRI decreased from 3.0 cases per 100,000 live births in the pre-vaccine era (1950 to 1954)Footnote j to 0.1 cases per 100,000 live births from 2015 to 2019. More recent data on CRS/CRI can be found in the Measles and Rubella Weekly Monitoring Reports.

Epidemiology between 2015 and 2019

From 2015 to 2019, one case of CRS/CRI was reported in Canada in 2015, resulting in an incidence rate of 0.3 cases per 100,000 live births for that year. The case was hospitalized and was due to maternal exposure to rubella outside of Canada. There have been no reported cases of CRS/CRI due to rubella exposure within Canada since 2000. This indicates that Canada is on track to meet its disease reduction target of zero cases of CRS/CRI by year 2025.

Rubella vaccination coverage

CRS/CRI can be prevented by ensuring that women of childbearing age are vaccinated against rubella. Currently, no vaccine coverage estimates are available for this group. In recent seroprevalence studies of cohorts of pregnant women in Canada, from 2006 to 2012, the percentage of study participants immune to rubella ranged from 84% to 92% Footnote 13,Footnote 14,Footnote 15.

Further reading

Polio and acute flaccid paralysis (AFP)

Key points:

Polio vaccine was introduced in Canada in 1955. Vaccine programs switched from oral poliovirus vaccine (OPV) to inactivated poliomyelitis vaccines (IPV) exclusively in 1995/1996. Although Canada was certified polio-free in 1994, surveillance of poliomyelitis through systems monitoring for polio-like illness is essential due to the risk of importation from polio-endemic regions, vaccine-derived poliovirus importation from countries using the OPV and the existence of non-immunized populations in Canada. Between 2004 and 2012 in Canada, four cases of Sabin-derived poliovirus were detected in infants who had travelled to and were vaccinated in countries using OPV Footnote 6. During the 1950s, the incidence of polio in Canada was dramatically reduced with the introduction of vaccination programs. The average incidence rate of polio decreased from 17.5 cases per 100,000 population in the pre-vaccine era (1950 to 1954)Footnote k to zero from 2015 to 2019 (Figure 5). Based on data for this period, Canada is on track to meet its disease reduction target of zero cases of polio by 2025.

Active surveillance remains critical until global polio eradication has been achieved. As of 2019, polio continues to be endemic in two countries around the world: Afghanistan and Pakistan Footnote 16. As recommended by the WHO, Canada conducts AFP surveillance in children and youth less than 15 years of age to monitor for polio. AFP is the acute onset of paralysis in one or more limbs and is a characteristic of polio Footnote 4. Incidence rates of AFP appear to show a cyclical pattern, with increases observed every two to five years.

AFP epidemiology between 2015 and 2019

From 2015 to 2019 in Canada, a total of 220 AFP cases were reported in children under 15 years of age. An average of 44 cases were reported annually (range: 27 to 73) with the average incidence rate of 0.7 cases per 100,000 population (range: 0.5 to 1.2) (Figure 5). Fifty-four percent of the cases were male. The highest incidence rate of AFP since 1996 was reported in 2018 (Figure 5). This spike in cases could be attributed to an increase in the number of cases of a specific type of AFP, acute flaccid myelitis (AFM) in the United States, which may have resulted in increased awareness of AFM among Canadian clinicians Footnote 17.

All cases were adjudicated against the polio case definition and none were assessed to be polio. Most reported cases were diagnosed with either Guillain-Barré syndrome (46%) or transverse myelitis (24%).

Figure 5: Number and incidence rate (per 100,000 population) of reported acute flaccid paralysis cases in children less than 15 years of age, in Canada by year, 1996 to 2019Footnote l
Figure 5: Text equivalent
Number and incidence rate (per 100,000 population) of reported acute flaccid paralysis cases in children less than 15 years of age, in Canada by year, 1996 to 2019
Year Cases Incidence rate (per 100,000 population)
1996 27 0.5
1997 35 0.6
1998 43 0.7
1999 60 1.0
2000 63 1.1
2001 53 0.9
2002 44 0.8
2003 44 0.8
2004 38 0.7
2005 54 0.9
2006 38 0.7
2007 50 0.9
2008 43 0.8
2009 58 1.0
2010 47 0.8
2011 44 0.8
2012 33 0.6
2013 36 0.6
2014 50 0.9
2015 27 0.5
2016 52 0.9
2017 32 0.5
2018 72 1.2
2019 34 0.6

Polio vaccination coverage

Based on the 2019 cNICS, Canada falls slightly below the 95% national coverage goal with 92% of children in Canada receiving the recommended three doses of polio-containing vaccine by two years of age Footnote 11.

Further reading

Summary

The average annual incidence of each of these diseases under elimination has declined by over 99% from the pre-vaccination era to the time-period 2015 to 2019. This steep decline can be largely attributed to routine vaccinations. Canada's elimination status was maintained for measles, rubella, congenital rubella syndrome/congenital rubella infection (CRS/CRI), and polio. Canada is on track to meet national VPD reduction targets for these diseases by 2025. However, improvements are necessary to achieve the 95% vaccine coverage goal as vaccine coverage for measles, rubella, and polio remains below 95% among children two years of age.

Vaccine preventable diseases with low-level incidence in Canada

Diphtheria

Key points:

Vaccination against diphtheria has dramatically reduced its mortality and morbidity. With routine vaccination, the incidence of diphtheria has declined by over 99% from an average incidence rate of 84.2 cases per 100,000 population in the pre-vaccine era (1925 to 1929)Footnote m to 0.01 cases per 100,000 population from 2015 to 2019 (Figure 6).

Figure 6: Number and incidence rates (per 100,000 population) of reported diphtheria cases in Canada by year, 1924 to 2019
Figure 6: Text equivalent
Number and incidence rates (per 100,000 population) of reported diphtheria cases in Canada by year, 1924 to 2019
Year Cases Incidence rate (per 100,000 population)
1924 9,057 100.1
1925 7,244 78.8
1926 7,175 76.7
1927 8,501 89.1
1928 8,781 90.2
1929 9,010 90.0
1930 8,036 78.8
1931 5,914 57.1
1932 3,912 37.3
1933 2,377 22.4
1934 2,267 21.1
1935 1,999 18.5
1936 2,031 18.6
1937 2,945 26.7
1938 3,676 33.0
1939 2,897 25.8
1940 2,335 20.5
1941 2,866 24.9
1942 2,955 25.4
1943 2,804 23.8
1944 3,223 27.0
1945 2,786 23.1
1946 2,535 20.7
1947 1,550 12.4
1948 898 7.0
1949 806 6.2
1950 421 3.1
1951 253 1.8
1952 190 1.3
1953 132 0.9
1954 208 1.4
1955 139 0.9
1956 135 0.8
1957 142 0.9
1958 66 0.4
1959 38 0.2
1960 55 0.3
1961 91 0.5
1962 71 0.4
1963 75 0.4
1964 23 0.1
1965 51 0.3
1966 38 0.2
1967 41 0.2
1968 61 0.3
1969 48 0.2
1970 47 0.2
1971 75 0.3
1972 68 0.3
1973 169 0.7
1974 173 0.8
1975 103 0.4
1976 109 0.5
1977 124 0.5
1978 119 0.5
1979 84 0.3
1980 55 0.2
1981 7 <0.1
1982 11 <0.1
1983 11 <0.1
1984 8 <0.1
1985 9 <0.1
1986 6 <0.1
1987 4 <0.1
1988 4 <0.1
1989 9 <0.1
1990 7 <0.1
1991 5 <0.1
1992 1 <0.1
1993 1 <0.1
1994 3 <0.1
1995 2 <0.1
1996 0 <0.1
1997 1 <0.1
1998 0 <0.1
1999 1 <0.1
2000 0 <0.1
2001 0 <0.1
2002 1 <0.1
2003 1 <0.1
2004 0 <0.1
2005 0 <0.1
2006 0 <0.1
2007 3 <0.1
2008 2 <0.1
2009 2 <0.1
2010 2 <0.1
2011 1 <0.1
2012 0 <0.1
2013 0 <0.1
2014 2 <0.1
2015 2 <0.1
2016 1 <0.1
2017 10 <0.1
2018 9 <0.1
2019 3 <0.1

Epidemiology between 2015 and 2019

From 2015 to 2019, a total of 25 diphtheria cases were reported in Canada and 76% of these cases occurred in 2017 and 2018. An average of five cases were reported per year (range: one to 10) with the average incidence rate of 0.014 cases per 100,000 population (range: 0.003 to 0.027 cases per 100,000 population) (Figure 6). All ages were affected, with the most cases among those 40 to 59 year of age (seven cases) and five to nine years of age (five cases). The current national case definition for diphtheria captures both respiratory and cutaneous diphtheria, with no distinction between the types of infection. Therefore, surveillance data is not available to assess the reduction target of zero annual cases of respiratory diphtheria resulting from exposure by 2025 in Canada.

Diphtheria vaccination coverage

Based on the 2019 cNICS, the 95% goal for childhood vaccine coverage has not been met: 78% of children in Canada received the recommended four doses of diphtheria-containing vaccine by two years of age and 78% received the recommended five doses by seven years of age. The 90% goal for adolescent vaccine coverage has been met as 95% received a booster dose during adolescence Footnote 11.

Further reading

Tetanus

Key points:

Unlike other VPDs, tetanus is not transmitted from person-to-person and while cases have always been relatively rare in Canada, they are generally severe. As tetanus is not communicable, vaccination programs were introduced with a focus on individual protection instead of herd immunity and all provinces and territories had routine tetanus vaccination programs by the 1940s Footnote 10. With routine vaccination, the incidence of tetanus has declined by 95% from an average incidence rate of 0.2 cases per 100,000 population in the pre-vaccine era (1935 to 1939)Footnote n to 0.01 cases per 100,000 population from 2015 to 2019 (Figure 7).

Figure 7: Number and incidence rates (per 100,000 population) of reported tetanus casesFootnote o in Canada by year, 1935 to 2019
Figure 7: Text equivalent
Number and incidence rates (per 100,000 population) of reported tetanus cases in Canada by year, 1935 to 2019
Year Cases Incidence rate (per 100,000 population)
1935 43 0.4
1936 38 0.3
1937 33 0.3
1938 26 0.2
1939 41 0.4
1940 25 0.2
1941 22 0.2
1942 20 0.2
1943 15 0.1
1944 16 0.1
1945 8 0.1
1946 9 0.1
1947 9 0.1
1948 13 0.1
1949 25 0.2
1950 22 0.2
1951 14 0.1
1952 12 0.1
1953 12 0.1
1954 12 0.1
1955 14 0.1
1956 5 <0.1
1957 9 0.1
1958 10 0.1
1959 10 0.1
1960 12 0.1
1961 19 0.1
1962 9 <0.1
1963 11 0.1
1964 15 0.1
1965 9 <0.1
1966 5 <0.1
1967 12 0.1
1968 9 <0.1
1969 7 <0.1
1970 11 0.1
1971 6 <0.1
1972 3 <0.1
1973 3 <0.1
1974 8 <0.1
1975 1 <0.1
1976 7 <0.1
1977 9 <0.1
1978 5 <0.1
1979 0 <0.1
1980 0 <0.1
1981 0 <0.1
1982 0 <0.1
1983 6 <0.1
1984 2 <0.1
1985 9 <0.1
1986 4 <0.1
1987 7 <0.1
1988 3 <0.1
1989 4 <0.1
1990 6 <0.1
1991 4 <0.1
1992 4 <0.1
1993 10 <0.1
1994 4 <0.1
1995 7 <0.1
1996 3 <0.1
1997 4 <0.1
1998 2 <0.1
1999 6 <0.1
2000 4 <0.1
2001 8 <0.1
2002 1 <0.1
2003 1 <0.1
2004 3 <0.1
2005 4 <0.1
2006 2 <0.1
2007 6 <0.1
2008 2 <0.1
2009 2 <0.1
2010 4 <0.1
2011 2 <0.1
2012 4 <0.1
2013 2 <0.1
2014 6 <0.1
2015 4 <0.1
2016 5 <0.1
2017 4 <0.1
2018 1 <0.1
2019 4 <0.1

Epidemiology between 2015 and 2019

From 2015 to 2019, a total of 18 cases of tetanus were reported in Canada. An average of four cases were reported per year (range: one to five) with the average incidence rate of 0.01 cases per 100,000 population (range: 0.003 to 0.014) (Figure 7). The large majority of the cases were in adults 20 years of age and older. Based on the data for this period, Canada is on track to meet its reduction target of less than five cases of tetanus annually by 2025. Maternal and neonatal tetanus was eliminated in the Region of the Americas in 2017 Footnote 18. However, surveillance data is not currently available to assess reduction targets of zero cases of maternal/neonatal tetanus in Canada by 2025. Work is currently underway to estimate maternal and neonatal tetanus case counts based on diagnostic codes from Canadian hospital databases and consultations with provincial and territorial partners.

Tetanus vaccination coverage

Based on the 2019 cNICS, only 78% of children in Canada received the recommended four doses of tetanus-containing vaccine by two years of age and only 78% received the recommended five doses by seven years of age, which is below the national vaccination coverage goal of 95% Footnote 11. Based on the 2018-2019 Seasonal Influenza Vaccine Coverage Survey, only 69% of adults received a tetanus-containing vaccine and only 58% of Canadians 65 years of age and older received the vaccine Footnote 19.

Further reading

Invasive disease due to Haemophilus influenza serotype b (Hib)

Key points:

Prior to the introduction of the Hib vaccine into provincial and territorial routine childhood vaccination schedules in 1988, Hib was the most common cause of bacterial meningitis in Canada Footnote 10, particularly among infants. With routine vaccination, the incidence of invasive disease due to Hib has declined by 99% in children less than five years of age, from 34.6 cases per 100,000 population in the pre-vaccine era (1986 to 1987)Footnote p to 0.3 cases per 100,000 population from 2015 to 2019. In the general population, invasive disease due to Hib has declined by 98% from 2.6 cases per 100,000 population in the pre-vaccine era (1986 to 1987) to 0.04 cases per 100,000 population from 2015 to 2019 (Figure 8). However, the average age-standardized incidence rate in northern Canada was 8.8 times higher than the rest of Canada between 2001 and 2018Footnote q.

Figure 8: Number and incidence rates (per 100,000 population) of reported cases of invasive disease due to Hib in Canada by year, 1986 to 2019
Figure 8: Text equivalent
Number and incidence rates (per 100,000 population) of reported cases of invasive disease due to Hib in Canada by year, 1986 to 2019
Year Cases Incidence rate (per 100,000 population)
1986 694 2.7
1987 670 2.5
1988 798 3.0
1989 979 3.6
1990 529 1.9
1991 353 1.3
1992 284 1.0
1993 130 0.5
1994 72 0.2
1995 62 0.2
1996 69 0.2
1997 71 0.2
1998 56 0.2
1999 21 0.1
2000 33 0.1
2001 46 0.1
2002 50 0.2
2003 44 0.1
2004 38 0.1
2005 30 0.1
2006 32 0.1
2007 27 0.1
2008 44 0.1
2009 18 0.1
2010 17 0.1
2011 27 0.1
2012 24 0.1
2013 33 0.1
2014 26 0.1
2015 27 0.1
2016 12 <0.1
2017 18 0.1
2018 11 <0.1
2019 12 <0.1

Epidemiology between 2015 and 2019

From 2015 to 2019, a total of 80 cases of invasive Hib were reported in Canada. An average of 16 cases were reported per year (range: 11 to 27) with the average incidence rate of 0.04 cases per 100,000 population (range: 0.03 to 0.08) (Figure 8). Cases were reported in almost every age group; however, the highest incidence rates were reported in children under five years of age, followed by adults 60 years of age and over (Figure 9). Males accounted for 64% of all cases.

Based on data obtained through IMPACT, a total of 21 paediatric cases were hospitalized due to Hib from 2015 to 2019, averaging four cases per year (range: one to nine). Of those, 52% were male and 67% were in infants under one year of age. A total of four cases of preventable HibFootnote r were reported among children less than five years of age. No deaths due to Hib were reported by IMPACT. Based on data for this period, Canada is on track to meet its disease reduction target of less than five cases of preventable Hib annually in children less than five years of age by 2025.

Figure 9: Total number and overall incidence rate (per 100,000 population) of reported cases of invasive disease due to Hib in Canada by age group, 2015 to 2019 (n=87)
Figure 9: Text equivalent
Total number and overall incidence rate (per 100,000 population) of reported cases of invasive disease due to Hib in Canada by age group, 2015 to 2019 (n=87)
Age groups Total number of cases Overall incidence rate
(per 100,000 population)
< 1 16 0.8
1 to 4 14 0.2
5 to 9 2 <0.1
10 to 14 1 <0.1
15 to 19 1 <0.1
20 to 24 0 <0.1
25 to 29 4 <0.1
30 to 39 8 <0.1
40 to 59 15 <0.1
≥ 60 19 <0.1

Haemophilus influenzae serotype b vaccination coverage

Based on the 2019 cNICS, only 74% of children in Canada received the recommended four doses of Hib-containing vaccine by two years of age and 80% received the recommended four doses by seven years of age Footnote 11. Thus, the 95% vaccine coverage goal by two years of age for the Hib vaccine is not achieved.

Further reading

Invasive meningococcal disease (IMD)

Key points:

Between 2002 and 2007, a variety of routine childhood and adolescent meningococcal vaccination programs using monovalent (targeting serogroup C) and quadrivalent (targeting serogroups A, C, W-135, and Y) conjugate vaccines were implemented in Canadian provinces and territories Footnote 20. The overall incidence of IMD decreased by 60% from an average incidence rate of 0.8 cases per 100,000 population in the pre-vaccine era (1997 to 2001)Footnote s to 0.3 cases per 100,000 population from 2015 to 2019 (Figure 10). With routine vaccination, the incidence of IMD serogroup C has declined by 94%, from an average incidence rate of 0.3 cases per 100,000 population in the pre-vaccine era (1997 to 2001) to 0.01 cases per 100,000 population from 2015 to 2019 (Figure 11).

Although serogroup B is responsible for the majority of IMD cases, the incidence rate has been declining overall since it peaked in 2007. While vaccines targeting IMD serogroup B are not currently part of routine vaccination programs in Canada, meningococcal B vaccines have been used during outbreaks.

Figure 10: Number and incidence rate (per 100,000 population) of reported invasive meningococcal disease cases in Canada by year, 1997 to 2019

Figure 10: Text equivalent
Number and incidence rate (per 100,000 population) of reported invasive meningococcal disease cases in Canada by year, 1997 to 2019
Year Cases Incidence rate
(per 100,000 population)
1997 265 0.9
1998 174 0.6
1999 214 0.7
2000 242 0.8
2001 366 1.2
2002 234 0.7
2003 195 0.6
2004 196 0.6
2005 182 0.6
2006 212 0.7
2007 233 0.7
2008 195 0.6
2009 212 0.6
2010 154 0.5
2011 175 0.5
2012 154 0.4
2013 121 0.3
2014 101 0.3
2015 108 0.3
2016 99 0.3
2017 119 0.3
2018 141 0.4
2019 138 0.4
Figure 11: Incidence of IMD (per 100,000 population) in Canada by serogroup and year, 1997 to 2019Footnote t

Figure 11: Text equivalent
Incidence of IMD (per 100,000 population) in Canada by serogroup and year, 1997 to 2019
Year Incidence rate by serogroup (per 100,000 population)
B C Y W-135 Other
1997 0.36 0.23 0.11 0.03 0.14
1998 0.22 0.13 0.06 0.02 0.16
1999 0.30 0.21 0.06 0.04 0.10
2000 0.22 0.34 0.08 0.03 0.12
2001 0.28 0.60 0.10 0.03 0.17
2002 0.29 0.25 0.12 0.02 0.05
2003 0.26 0.15 0.13 0.05 0.02
2004 0.27 0.17 0.08 0.04 0.04
2005 0.30 0.12 0.07 0.05 0.02
2006 0.35 0.13 0.08 0.02 0.07
2007 0.40 0.09 0.11 0.04 0.06
2008 0.29 0.09 0.11 0.04 0.04
2009 0.38 0.06 0.10 0.04 0.05
2010 0.27 0.03 0.08 0.02 0.04
2011 0.31 0.01 0.10 0.03 0.05
2012 0.32 0.04 0.05 0.01 0.03
2013 0.23 0.02 0.07 0.01 0.02
2014 0.15 0.03 0.08 0.02 0.01
2015 0.18 0.01 0.07 0.03 0.02
2016 0.13 0.01 0.07 0.04 0.02
2017 0.13 0.02 0.06 0.08 0.03
2018 0.07 0.02 0.05 0.12 0.03
2019 0.11 0.01 0.07 0.12 0.05

Epidemiology between 2015 and 2019

From 2015 to 2019, a total of 606 IMD cases were reported in Canada. An average of 121 cases were reported per year (range: 99 to 141), with an average incidence rate of 0.3 per 100,000 population (range: 0.3 to 0.4) (Figure 10). Though cases were reported in every age group, the highest incidence rates were observed in infants less than one year of age followed by children from one to four years of age (3.2 cases and 0.8 cases per 100,000 population, respectively). The lowest overall incidence rate was reported among those five to nine years of age and 10-14 years of age (0.1 cases per 100,000 population for both), although the incidence rate among those 30-39 years of age was similar (0.2 cases per 100,000 population) (Figure 12). Cases were relatively evenly distributed across the sexes (48% males and 52% females on average, annually). During this time, 47 IMD-associated deaths were reported to the eIMDSS, for a case-fatality rate of 7.8%.

Figure 12: Total reported cases and overall incidence rate (per 100,000 population) of invasive meningococcal disease in Canada by age group, 2015 to 2019 (n=605)Footnote u

Figure 12: Text equivalent
Total reported cases and overall incidence rate (per 100,000 population) of invasive meningococcal disease in Canada by age group, 2015 to 2019 (n=605)
Age groups Total number of cases Overall incidence rate (per 100,000 population)
< 1 61 3.2
1 to 4 64 0.8
5 to 9 13 0.1
10 to 14 13 0.1
15 to 19 61 0.6
20 to 24 55 0.5
25 to 29 23 0.2
30 to 39 38 0.2
40 to 59 100 0.2
≥ 60 176 0.4

A decline in incidence rates for serogroup B has been observed since 2015. Incidence rates for serogroup W-135 have been increasing and other serogroups remained stable (Figure 11). IMD serogroup B was responsible for most cases in all age groups (total of 241 cases accounting for 40% of all IMD cases) and the highest incidence rates were observed in infants less than one year of age followed by children from one to four years of age (1.9 cases and 0.5 cases per 100,000 population, respectively). There was a total of 157 IMD serogroup W-135 cases which accounts for 26% of all IMD cases. Similar to serogroup B, serogroup W-135 affected mostly those less than one year of age with an incidence rate of 0.7 cases per 100,000 population, although the majority of serogroup W-135 cases were older individuals (59% of cases among those 40 years and older). There was a total of 126 IMD serogroup Y cases accounting for 21% of all IMD cases; individuals aged 15 to 19 and 20 to 24 years of age were most affected with both having an incidence rate of 0.1 cases per 100,000 population. Disease caused by serogroup C remained rare, accounting for only 4% of IMD cases (total of 27 cases). Seven cases of IMD caused by serogroup C were reported among those 18 years of age and under, with an average 1.4 cases per year. Based on data for this period, Canada is on track to meet its reduction target of less than five cases of IMD serogroup C annually in children less than 18 years of age by 2025.

Invasive meningococcal disease vaccination coverage

Based on the 2019 cNICS, 91% of children in Canada received the recommended one dose of meningococcal C vaccine by two years of age, falling slightly below the national vaccination coverage goal of 95% Footnote 11.

Further reading

Mumps

Key points:

Routine one-dose vaccination against mumps was implemented across provinces and territories between 1969 and 1983, with the second dose programs implemented between 1996 and 2001 Footnote 21. With routine vaccination, the incidence rate of mumps declined from 251.2 cases per 100,000 population during the pre-vaccine era (1950 to 1954)Footnote v to 2.0 cases per 100,000 population between 2015 and 2019 (Figure 13). However, mumps continues to be a cyclical disease in Canada, with outbreaks occurring every few years.

Figure 13: Number and incidence rate (per 100,000 population) of reported mumps casesFootnote w in Canada by year, 1950 to 2019
Figure 13: Text equivalent
Number and incidence rate (per 100,000 population) of reported mumps cases in Canada by year, 1950 to 2019
Year Cases Incidence rate (per 100,000 population)
1950 43,671 318.5
1951 35,189 251.2
1952 38,439 265.8
1953 36,297 244.5
1954 26,908 176.0
1955 27,193 173.2
1956 28,112 195.2
1957 22,386 166.1
1958 13,360 96.3
1959 No data No data
1960 No data No data
1961 No data No data
1962 No data No data
1963 No data No data
1964 No data No data
1965 No data No data
1966 No data No data
1967 No data No data
1968 No data No data
1969 No data No data
1970 No data No data
1971 No data No data
1972 No data No data
1973 No data No data
1974 No data No data
1975 No data No data
1976 No data No data
1977 No data No data
1978 No data No data
1979 No data No data
1980 No data No data
1981 No data No data
1982 No data No data
1983 No data No data
1984 No data No data
1985 No data No data
1986 836 3.2
1987 949 3.6
1988 792 2.9
1989 1,550 5.7
1990 535 1.9
1991 390 1.4
1992 330 1.2
1993 325 1.1
1994 356 1.2
1995 397 1.4
1996 290 1.0
1997 254 0.8
1998 114 0.4
1999 92 0.3
2000 81 0.3
2001 102 0.3
2002 200 0.6
2003 28 0.1
2004 33 0.1
2005 79 0.2
2006 42 0.1
2007 1,109 3.4
2008 748 2.2
2009 187 0.6
2010 768 2.3
2011 273 0.8
2012 48 0.1
2013 96 0.3
2014 40 0.1
2015 59 0.2
2016 365 1.0
2017 2,266 6.2
2018 808 2.2
2019 173 0.5

Epidemiology between 2015 and 2019

From 2015 to 2019, a total of 3,671 cases of mumps were reported nationally; however, 94% of the cases occurred in 2016, 2017 and 2018 and were mainly due to various outbreaks. These outbreaks occurred in multiple provinces during these three years and mainly involved the young adult population of 20 to 39 years of age Footnote 22. Although mumps is a cyclical disease with outbreaks occurring every few years, the incidence rate of mumps in 2018 was the highest since 1986, when mumps became notifiable in the post-vaccine era.

The five-year average of reported cases annually from 2015 to 2019 is 734 cases per year (range: 59 to 2,266, median: 365). The average incidence for this period was 2.0 cases per 100,000 population (range: 0.2 to 6.2) (Figure 13). The highest incidence rates were among those 20 to 24 years of age (5.0 cases per 100,000 population), followed by 15 to 19 years of age (4.5 cases per 100,000 population) and 25 to 29 years of age (4.5 cases per 100,000 population) (Figure 14). Due to large mumps outbreaks occurring in several provinces from 2016 to 2018, Canada is not currently on track to meet its reduction target of maintaining less than 100 cases of mumps annually (based on a five-year average) by 2025.

Figure 14: Total number and overall incidence rates (per 100,000 population) of reported mumps cases by age group, 2015 to 2019 (n=3,671)
Figure 14: Text equivalent
Total number and overall incidence rates (per 100,000 population) of reported mumps cases by age group, 2015 to 2019 (n=3,671)
Age groups Total number of cases Overall incidence rate (per 100,000 population)
< 1 18 0.9
1 to 4 93 1.2
5 to 9 206 2.0
10 to 14 261 2.7
15 to 19 480 4.5
20 to 24 611 5.0
25 to 29 567 4.5
30 to 39 747 3.0
40 to 59 616 1.2
≥ 60 72 0.2

Mumps vaccination coverage

Based on the 2019 cNICS, 89% of children in Canada received the recommended one dose of mumps-containing vaccine by two years of age and 83% received the recommended two doses by seven years of age, which is below the vaccine coverage goal of 95% Footnote 11.

Further reading

Summary

The average annual incidence from 2015 to 2019 of each of the VPDs with low incidence has declined over 90% compared to the pre-vaccination era. Based on surveillance data from 2015 to 2019, Canada is on track to meet national VPD reduction targets by 2025 for tetanus, Hib and IMD. If large outbreaks continue to occur, Canada is currently not on track to meet the reduction target for mumps. Presently, surveillance data is not available to assess progress in meeting national VPD reduction targets for respiratory diphtheria and maternal and neonatal tetanus. However, current work is underway to estimate maternal and neonatal tetanus case counts at the national level.

Although incidence rates for these diseases are low, vaccine coverage rates can be improved. Rates for diphtheria, tetanus and Hib by two years of age were all below 80%, which is considerably below the national vaccine coverage goal of 95%. Coverage among children two years of age for mumps-containing vaccine and meningococcal C vaccine were above 85%, but they were still below the national vaccine coverage goal of 95%.

Vaccine preventable diseases with moderate-level incidence in Canada

Pertussis

Key points:

Pertussis is an endemic and cyclical disease in Canada, with peaks at two to five-year intervals and increased case counts may be observed over several years. Despite this, Canada has experienced an overall decline in pertussis incidence since the introduction of the whole-cell pertussis vaccine in 1943, acellular vaccines in 1997/1998, and the addition of an adolescent acellular dose to provincial and territorial vaccine programs between 1999 and 2004 Footnote 23, Footnote 24. With routine vaccination, the incidence of pertussis has declined by 95% from an average incidence rate of 156.2 cases per 100,000 population in the pre-vaccine era (1938 to 1942)Footnote x to 8.0 cases per 100,000 population from 2015 to 2019 (Figure 15).

In 2018, NACI recommended that immunization with the tetanus, diphtheria, pertussis vaccine (Tdap) should be offered in every pregnancy irrespective of their previous immunization history Footnote 25. More recent recommendations on pertussis can be found in the National Advisory Committee on Immunization pertussis vaccine guidance document.

Figure 15: Number and incidence rate (per 100,000 population) of reported pertussis cases in Canada by year, 1938 to 2019
Figure 15: Text equivalent
Number and incidence rate (per 100,000 population) of reported pertussis cases in Canada by year, 1938 to 2019
Year Cases Incidence rate (per 100,000 population)
1938 16,003 143.7
1939 17,972 159.8
1940 19,878 174.9
1941 16,647 144.9
1942 18,384 158.0
1943 19,082 162.0
1944 12,384 103.8
1945 12,192 101.1
1946 7,671 62.5
1947 10,324 82.4
1948 7,084 55.3
1949 7,961 59.3
1950 12,182 89.0
1951 8,889 63.6
1952 8,520 59.0
1953 9,387 63.3
1954 11,600 76.0
1955 13,682 87.3
1956 8,513 52.9
1957 7,459 44.9
1958 6,932 40.6
1959 7,259 41.5
1960 5,993 33.6
1961 5,476 30.1
1962 8,076 43.5
1963 6,134 32.4
1964 4,844 25.1
1965 2,472 12.6
1966 4,555 22.8
1967 4,949 24.3
1968 2,505 12.1
1969 1,242 5.9
1970 2,098 9.9
1971 3,002 13.7
1972 1,297 5.8
1973 997 4.4
1974 1,579 6.9
1975 3,387 14.6
1976 3,002 12.8
1977 1,988 8.4
1978 2,666 11.1
1979 2,227 9.2
1980 2,873 11.7
1981 2,632 10.6
1982 2,314 9.2
1983 2,232 8.8
1984 1,353 5.3
1985 2,433 9.4
1986 2,557 9.8
1987 1,483 5.6
1988 1,301 4.9
1989 3,943 14.5
1990 8,330 30.1
1991 2,534 9.0
1992 3,763 13.2
1993 7,537 26.2
1994 10,116 34.8
1995 9,308 31.7
1996 5,230 17.6
1997 4,281 14.3
1998 8,896 29.4
1999 5,862 19.2
2000 4,748 15.4
2001 2,945 9.5
2002 3,199 10.2
2003 3,239 10.2
2004 3,104 9.7
2005 2,492 7.7
2006 2,346 7.2
2007 1,493 4.5
2008 1,967 5.9
2009 1,628 4.8
2010 750 2.2
2011 694 2.0
2012 4,653 13.4
2013 1,281 3.6
2014 1,531 4.3
2015 3,522 9.8
2016 3,951 10.9
2017 3,586 9.8
2018 1,467 3.9
2019 2,120 5.6

Epidemiology between 2015 and 2019

From 2015 to 2019, a total of 14,646 cases of pertussis were reported, averaging 2,929 cases per year (range: 1,467 to 3,951). The average annual incidence rate was 8.0 cases per 100,000 population (range: 3.9 to 10.9). Higher incidence rates were observed between 2015 and 2017 (Figure 15). Although cases were reported across all age groups, incidence rates were highest in children under 15 years of age, especially in infants less than one year of age (Figure 16). Overall, 55% of the cases were female.

Based on data obtained through IMPACT, from 2015 to 2019, a total of 273 (average: 55, range: 24-78) paediatric cases were hospitalized due to pertussis from 2015 to 2019. Of those, 52% were female. Most of the cases (89%) were in infants under six months of age. Of those, nearly half (49%) were in infants less than two months of age. A total of three deaths due to pertussis were reported and all were in infants under six months of age. Based on three-year rolling average data from this period, Canada is on track to meet its disease reduction target of less than three deaths annually in infants less than six months of age by 2025.

Figure 16: Total number and overall incidence rates (per 100,000 population) of reported pertussis cases in Canada, by age group, 2015 to 2019 (n=14,646)Footnotey

Figure 16: Text equivalent
Total number and overall incidence rates (per 100,000 population) of reported pertussis cases in Canada, by age group, 2015 to 2019 (n=14,646)
Age groups Total number of cases Overall incidence rate (per 100,000 population)
< 1 1,171 60.9
1 to 4 2,459 31.5
5 to 9 2,855 28.3
10 to 14 3,076 31.2
15 to 19 902 8.5
20 to 24 458 3.8
25 to 29 397 3.1
30 to 39 1,100 4.4
40 to 59 1,691 3.3
≥ 60 529 1.2

Pertussis vaccination coverage

Based on the 2019 cNICS, only 78% of children in Canada received the recommended four doses of pertussis-containing vaccine by two years of age and 78% received the recommended five doses by seven years of age, which did not meet the 95% vaccine coverage goal. However, the 90% adolescent vaccine coverage goal was met because 95% received the recommended one dose of the booster by 17 years of age Footnote 11. According to the 2018-2019 Seasonal Influenza Vaccination Coverage Survey, 33% of adults in Canada received one dose of the pertussis-containing vaccine in adulthood Footnote 19.

Further reading

Invasive pneumococcal disease (IPD)

Key points:

Streptococcus pneumoniae (pneumococcus) is the leading cause of invasive bacterial infections and bacterial pneumonia in young children. IPD became nationally notifiable in 2000; before this time, only cases of pneumococcal meningitis were notifiable nationally. Following a period of instability in incidence rates due to this change in reporting practice, overall annual incidence rates of IPD have remained relatively stable since 2003, ranging between 8.9 and 9.5 cases per 100,000 population per year (Figure 17). However, age-standardized incidence rates between 2001 and 2018 were 2.8 times higher in northern Canada than elsewhere in the countryFootnote z.

Figure 17: Number and incidence rate (per 100,000 population) of reported IPD cases in Canada, by year, 2001 to 2019Footnote aa
Figure 17: Text equivalent
Number and incidence rate (per 100,000 population) of reported IPD cases in Canada, by year, 2001 to 2019
Year Cases Incidence rate (per 100,000 population)
2001 1,733 5.6
2002 2,261 7.2
2003 2,725 8.6
2004 2,914 9.1
2005 2,857 8.8
2006 2,883 8.8
2007 3,247 9.8
2008 3,192 9.6
2009 3,291 9.8
2010 3,344 9.8
2011 3,307 9.6
2012 3,419 9.8
2013 3,185 9.0
2014 3,177 8.9
2015 3,211 9.0
2016 3,290 9.1
2017 3,478 9.5
2018 4,026 10.8
2019 3,758 9.9

NACI recommends routine immunization against IPD for those aged two years and under and those aged 65 years of age and older Footnote 26,Footnote 27. In the absence of national surveillance data prior to 2000, incidence rates for children less than two years of age (between 1994 and 1999) were estimated by various studies and ranged from 58.8 cases to 112.2 cases per 100,000 population Footnote 28. Following the implementation of routine pneumococcal childhood vaccination between 2002 and 2006, IPD incidence among children less than two years of age decreased to an average of 16.2 cases per 100,000 population from 2015 to 2019 (Figure 18). The proportion of IPD due to serotypes covered by the PCV7 vaccine decreased considerably following its introduction in all provinces and territories by 2006 Footnote 29,Footnote 30,Footnote 31,Footnote 32. By 2010, serotypes covered by the PCV7 vaccine represented 6% of all IPD cases in children 14 years of age and under, while responsible for over 80% of invasive disease in children during the pre-conjugate vaccine era Footnote 30,Footnote 33.

Following the introduction of the PCV13 vaccine in all provinces and territories by 2011, PCV13-specific serotype cases have declined in all ages from 46% in 2010 to 21% in 2018 Footnote 34,Footnote 35. Although the 23-valent pneumococcal polysaccharide vaccine has been licensed for use in Canada since 1983 and included in routine vaccination programs for those 65 years of age and older in all provinces and territories by 2000 Footnote 36, the average incidence in this age group has remained relatively unchanged since the early 2000s (Figure 18).

Figure 18: Annual incidence rate of IPD among age <2 and age 65 and up, 2001 to 2019Footnote ab
Figure 18: Text equivalent
Annual incidence rate of IPD among age <2 and age 65 and up, 2001 to 2019
Year Incidence rate per age groups
(per 100,000 population)
<2 65+
2001 51.4 12.9
2002 69.4 18.9
2003 73.0 22.5
2004 55.1 25.1
2005 33.6 23.5
2006 22.7 23.5
2007 30.2 24.6
2008 29.3 25.5
2009 29.7 26.1
2010 26.1 26.5
2011 23.5 24.8
2012 19.3 26.0
2013 18.8 24.7
2014 18.7 24.4
2015 17.1 23.6
2016 17.6 22.7
2017 16.5 24.0
2018 15.7 25.8
2019 14.4 23.2

Epidemiology between 2015 and 2019

From 2015 to 2019, a total of 17,763 IPD cases were reported in Canada. An average of 3,553 cases were reported per year (range: 3,211 to 4,026), with an average incidence rate of 9.7 cases per 100,000 population (range: 9.0 to 10.8) (Figure 17). Although cases were reported across all age groups, the highest incidence rates were in adults aged 60 years of age and older (21.2 cases per 100,000 population), followed by infants less than one year (13.9 cases per 100,000) and children aged one to four years of age (11.6 cases per 100,000) (Figure 19). Males accounted for 55% of all cases. Based on data for this period, Canada is not currently on track to meet the 5% disease reduction target for IPD in adults 65 years of age and older by 2025 because the incidence rate in this age group has remained relatively stable since the early 2000s.

Based on data obtained through IMPACT, a total of 716 paediatric cases were hospitalized due to IPD from 2015 to 2019, averaging 143 cases per year (range: 123 to 164). Of those, 57% were male. Most of the cases (68%) were in children less than five years of age. Approximately 76% of the cases had information on IPD serotypes. Of these, approximately 76% were due to serotypes not included in the pneumococcal conjugate 13-valent (Pneu-C-13) vaccine. A total of 22 deaths due to IPD were reported between 2015 and 2019 through IMPACT, ranging from two to eight deaths per year. The majority (77%) were in children under five years of age.

Figure 19: Total number and overall incidence rate (per 100,000 population) of reported invasive pneumococcal disease cases in Canada by age group, 2015 to 2019 (n=17,763)
Figure 19: Text equivalent
Total number and overall incidence rate (per 100,000 population) of reported invasive pneumococcal disease cases in Canada by age group, 2015 to 2019 (n=17,763)
Age groups Total number of cases Overall incidence rate (per 100,000 population)
< 1 268 13.9
1 to 4 904 11.6
5 to 9 366 3.6
10 to 14 119 1.2
15 to 19 150 1.4
20 to 24 226 1.9
25 to 29 366 2.9
30 to 39 1,315 5.2
40 to 59 4,931 9.7
≥ 60 9,104 21.2

IPD vaccination coverage

Based on the 2019 cNICS, only 84% of children in Canada received the recommended doses of pneumococcal vaccine by two years of age Footnote 11. Based on the 2018-2019 Seasonal Influenza Vaccination Coverage Survey, only 58% of adults 65 years of age and older in Canada received a pneumococcal vaccine Footnote 19. Neither the 95% vaccination coverage goal for children by two years of age nor the 80% vaccination coverage goal for adults 65 years of age and older were met.

Further reading

Varicella

Key points:

The varicella vaccine was first approved in Canada in 1998 and routine varicella vaccination programs were implemented in Canadian provinces and territories between 2000 and 2007 Footnote 37. Based on data from reporting jurisdictions, the average incidence of varicella has declined by approximately 99% from 213.3 cases per 100,000 population in the pre-vaccine era (1993 to 1997)Footnote ac to an average incidence of 2.0 cases per 100,000 population between 2015 and 2019 (Figure 20).

Figure 20: Number and incidence rate (per 100,000 population) of reportedFootnote ad varicella cases in Canada by year, 1991 to 2019
Figure 20: Text equivalent
Number and incidence rate (per 100,000 population) of reported varicella cases in Canada by year, 1991 to 2019
Year Cases Incidence rate
(per 100,000 population)
1991 12,773 134.8
1992 20,001 207.9
1993 49,779 294.7
1994 40,416 236.9
1995 41,087 238.4
1996 20,077 122.4
1997 28,866 174.0
1998 32,024 189.9
1999 24,509 143.7
2000 34,866 201.7
2001 17,515 105.8
2002 19,761 117.6
2003 17,572 103.4
2004 1,734 10.1
2005 1,750 10.0
2006 1,041 5.9
2007 870 4.9
2008 1,138 6.3
2009 933 18.1
2010 1,511 29.0
2011 681 3.7
2012 355 1.9
2013 456 2.4
2014 719 3.7
2015 695 3.5
2016 568 2.8
2017 311 1.6
2018 339 0.9
2019 453 1.2

Epidemiology between 2015 and 2019

Based on data from reporting jurisdictions, a total of 2,366 varicella cases were reported in Canada from 2015 to 2019. An average of 473 cases were reported per year (range: 311 to 694) with the average incidence rate of 2.0 cases per 100,000 population (range: 0.9 to 3.5) (Figure 20). Cases were reported in every age group; however, the highest overall incidence rate was reported among infants less than one year of age (9.4 cases per 100,000 population), followed by children aged 10 to 14 years of age (5.7 cases per 100,000 population), and five to nine years of age (4.5 cases per 100,000 population, Figure 21). Males accounted for 55% of all cases.

Figure 21: Total number and overall incidence rate (per 100,000 population) of reported varicella cases in Canada by age group, 2015 to 2019 (n=2,366)Footnote ae
Figure 21: Text equivalent
Total number and overall incidence rate (per 100,000 population) of reported varicella cases in Canada by age group, 2015 to 2019 (n=2,366)
Age groups Total number of cases Incidence rate (per 100,000 population)
< 1 133 6.9
1 to 4 229 2.9
5 to 9 342 3.4
10 to 14 418 4.2
15 to 19 266 2.5
20 to 24 236 1.9
25 to 29 176 1.4
30 to 39 262 1.0
40 to 59 218 0.4
≥ 60 84 0.2

Based on data from IMPACT, since the introduction of routine vaccination programs in 2000, the paediatric hospitalizations associated with serious varicella infections have declined from 398 hospitalizations to an annual average of 47 hospitalizations (range: 25 to 73) from 2015 to 2019 (Figure 22). During this surveillance period, the number of hospitalizations decreased from 73 cases in 2015 to 25 cases in 2019. Fifty-eight percent of the cases were male. The distribution of cases through age groups were highest in the one to four years of age (31%), followed by the five to nine years of age (29%) and infants under one year of age (22%). The majority of cases (81%) occurred among children who were immunocompromised, not eligible for vaccination, or not vaccinated. One death associated with varicella was reported through IMPACT during this period. Among children eligible for vaccinationFootnote af, an average of 13 hospitalizations were reported annually. Based on data from 2015 to 2019, Canada is on track to meet its VPD target of less than 50 hospitalizations annually due to varicella in vaccine-eligible children less than 18 years of age, by 2025.

Figure 22: Annual number of pediatric varicella hospitalizations in Canada reported through IMPACT, 1999 to 2019
Figure 22: Text equivalent
Annual number of pediatric varicella hospitalizations in Canada reported through IMPACT, 1999 to 2019
Year Number of pediatric varicella hospitalisations
1999 234
2000 398
2001 278
2002 305
2003 247
2004 271
2005 198
2006 152
2007 107
2008 59
2009 77
2010 69
2011 71
2012 61
2013 52
2014 68
2015 73
2016 58
2017 42
2018 37
2019 25

Varicella vaccination coverage

Based on the 2019 cNICS, only 83% of children in Canada received the recommended dose of varicella vaccine by two years of age, which is below the 95% vaccine coverage goal Footnote 11.

Further reading

Summary

There has been a decline of over 95% in the average annual incidence rate for pertussis and varicella during the period from 2015 to 2019 compared to the pre-vaccination era. Children are most vulnerable to these diseases, with the highest incidence rates being reported in infants under one year of age. The overall incidence rates for IPD have remained stable since 2003, with the highest rates reported in adults over the age of 60. Based on surveillance data from 2015 to 2019, Canada is on track to meet the VPD reduction target for pertussis and varicella by 2025 but is not on track for meeting the reduction target of a 5% reduction in IPD incidence for adults 65 years of age and older. Vaccination rates for pertussis, IPD, and varicella did not meet the national vaccination coverage goal of 95% by two years of age. Furthermore, the IPD vaccination rate did not meet the national coverage goal of 80% coverage for individuals 65 years of age and older.

Conclusion

The findings of this report underscore the pivotal role of publicly-funded infant, childhood and adult vaccination programs in reducing the burden of VPDs. For many VPDs, incidence rates have declined drastically in Canada since the pre-vaccine era. Surveillance data from 2015 to 2019 indicate that Canada is on track to meet national VPD reduction targets for measles, rubella, CRS/CRI, polio, diphtheria, tetanus, invasive disease due to Hib, IMD, pertussis, and varicella, but is at risk of not meeting the reduction targets for mumps and IPD by 2025.

Canada continues to maintain its elimination status for measles, rubella, CRS/CRI and polio. Despite the large number of measles cases due to imported cases, ongoing endemic transmission of the measles virus was not re-established in Canada. High vaccine coverage and strong surveillance are continue to be critical to retain the elimination status of these diseases.

Although achieving VPD reduction targets can be impacted by various factors, such as increases in mumps due to outbreaks, cyclical fluctuation of pertussis every two to five years, preventable cases of Hib among infants, imported cases of measles causing risks of secondary spread or serogroup conversion in IMD, the results described in this report indicate a pressing need to enhance vaccine coverage over the next few years in order for Canada to meet the reduction targets by 2025. Strong surveillance systems are important to monitor disease trends and burden, as well as to provide data for national vaccination recommendations and programs.

The greatest additional gains can come from understanding the characteristics of under-immunized and unimmunized populations and improving their vaccination coverage. History demonstrates that the importation of disease into under-immunized or unimmunized populations can result in outbreaks. Rates of vaccination need to be enhanced through clear, understandable and ongoing public communication about the risks and benefits of vaccination, especially when disease rates are low. Vaccines are one of the greatest achievements of biomedical science and public health. Continued commitment to vaccine programs is essential to advance their public health benefits.

Acknowledgements

We are grateful to local, provincial, and territorial public health staff for their continued support and tireless efforts in communicable disease surveillance and control as well as outbreak investigations. We also thank the healthcare providers and laboratorians who diligently report case information to their local health authorities. Finally, we thank IMPACT researchers and nurse monitors and the Canadian Pediatric Society for their work in elucidating the burden of vaccine preventable diseases in the hospitalized pediatric populations.

Appendix A: Methods and limitations

Surveillance data sources

Canadian Notifiable Disease Surveillance System

National surveillance data for polio, diphtheria, tetanus, invasive disease due to Haemophilus influenzae serotype b (Hib), mumps, pertussis, invasive pneumococcal disease (IPD), varicella, and historical data for measles (1950-2011) and rubella (1950-2012) were obtained through the Canadian Notifiable Disease Surveillance System (CNDSS), a surveillance system coordinated by the Public Health Agency of Canada (PHAC). Data aggregated by year, sex, province/territory, and age group are voluntarily provided annually by provincial and territorial partners. Age groups include infants less than one year of age, one to four years of age, five to nine years of age, ten to 14 years of age, 15 to 19 years of age, 20 to 24 years of age, 25 to 29 years of age, 30 to 39 years of age, 40 to 59 years of age, and adults 60 years of age and older. In addition, eight jurisdictions (British Columbia, Alberta, Saskatchewan, Ontario, Québec, Prince Edward Island, the Yukon, and Nunavut), provide case-level data to CNDSS. These jurisdictions accounted for approximately 90% of the Canadian population between 2015 and 2019. Data in this report are current as of June 2021.

Canadian Measles and Rubella Surveillance System

National enhanced surveillance data for measles (2012-2019), rubella (2013-2019), and CRS/CRI were obtained through the Canadian Measles and Rubella Surveillance System (CMRSS). Provincial and territorial departments of health submit case-level, non-nominal epidemiologic data weekly to PHAC on all cases that meet the national case definitions, including zero-reporting. The National Microbiology Laboratory (NML) provides genotype results for confirmed cases.

Enhanced Invasive Meningococcal Disease Surveillance System

National surveillance data for invasive meningococcal disease (IMD) were obtained through the enhanced Invasive Meningococcal Disease Surveillance System (eIMDSS). Provincial and territorial departments of health submit case-level, non-nominal epidemiologic and laboratory data annually to PHAC on all cases of IMD that meet the national case definition Footnote 38. Provincial and territorial public health and/or hospital laboratories send all Neisseria meningitidis isolates to the NML for confirmation and organism characterization. Deterministic matching on province/territory, date of birth or age, sex, onset date, and serogroup is conducted to link epidemiologic and laboratory data for cases with incomplete information.

Canada's Immunization Monitoring Program, ACTive

The Canadian Immunization Monitoring Program, Active (IMPACT) is a national surveillance initiative that monitors adverse events following immunization, vaccine failures and selected infectious diseases that are, or will be, vaccine preventable. IMPACT is managed by the Canadian Paediatric Society (CPS) and conducted by the IMPACT network of paediatric investigators at 12 tertiary care paediatric hospitals across Canada, which represent 90% of all tertiary care paediatric beds in Canada. Funding is provided by PHAC to the CPS for IMPACT. The IMPACT Data Monitoring Centre submits case-level, non-nominal epidemiologic and laboratory data quarterly to PHAC on hospitalizations in children 16 years of age and younger due to pertussis, varicella, IPD and Hib.

Canadian Acute Flaccid Paralysis Surveillance System

National surveillance data for acute flaccid paralysis (AFP) in children less than 15 years of age is a WHO-recommended strategy for detecting poliovirus circulation. National AFP surveillance data were obtained through the Canadian Acute Flaccid Paralysis Surveillance System (CAFPSS). Data are voluntarily provided by participating physicians and IMPACT nurse monitors who submit completed case report forms on an ongoing basis to the Canadian Paediatric Surveillance Program. The forms are then forwarded to PHAC for medical adjudication to rule out polio as the cause of AFP and to ensure that cases meet the national AFP case definition.

International Circumpolar Surveillance System of Invasive Bacterial Diseases

The International Circumpolar Surveillance (ICS) initiative is a population-based surveillance network of countries with circumpolar regions. Within Canada, six regions (Yukon, Northwest Territories, Nunavut, northern Labrador, Québec Cree, and Québec Nunavik) and a network of laboratories, including two references laboratories, the Laboratoire de santé publique du Québec and the National Microbiology Laboratory, participate in the program. Data collected include laboratory results, risk factors, clinical manifestation information, age, sex, and ethnicity details.

Vaccination coverage data sources

2019 Childhood National Immunization Coverage Survey

In Canada, national immunization coverage for childhood vaccines is monitored every two years by surveys conducted by Statistics Canada on behalf of PHAC through the childhood National Immunization Coverage Survey (cNICS). The cNICS is intended to determine if children are immunized in accordance with recommended immunization schedules for publicly-funded vaccines, to report vaccination coverage estimates to international organizations, and to develop appropriately targeted public education strategies.

Note: These reported numbers are most likely underestimates because data were collected primarily from parent-held vaccination records, in which some doses may be missing or recorded with incomplete information such as missing or illegible dates. In addition, in jurisdictions where vaccinations are recorded by vaccine and where the measles-mumps-rubella-varicella (MMRV) vaccine is in use, some doses of this vaccine may be recorded as MMR, thus leading to an under-counting of varicella vaccination.

2018-2019 Seasonal Influenza Vaccination Coverage Survey

Since 1991, PHAC has been monitoring national vaccination coverage for selected adult vaccines. It was first monitored through the adult National Immunization Coverage Survey (aNICS), which was first conducted in 2001 and has been routinely administered every two years since 2006. As of 2018, adult vaccine coverage was merged into the Seasonal Influenza Vaccination Coverage Survey. The Seasonal Influenza Vaccination Coverage Survey measures coverage for the flu shot in adults every year and includes other adult vaccine coverage every second year. Results from these national vaccine coverage surveys are used to monitor coverage at the national level for vaccines recommended by the National Advisory Committee on Immunization (NACI), to report vaccination coverage estimates against national coverage goals, and to inform vaccination program and public education strategies. Target populations include adults with or without chronic medical conditions and health care workers.

Population data sources

Population estimates

For all VPDs except CRS/CRI, denominator data for incidence rate calculations were obtained from Statistics Canada population estimates in October 1, 2020 Footnote 39.

Live births

For CRS/CRI, incidence rate by live births were obtained from CNDSS Notifiable disease charts Footnote 40.

Analyses

Analyses performed for this report include frequency counts, crude and age-specific incidence rates, and age and sex distributions as appropriate. Numerator data are from CNDSS, CMRSS, eIMDSS, IMPACT, and CAFPSS. Denominators are from population data and populations of those provinces and territories that did not submit data were removed from the denominators of incidence rate calculations. Case-fatality rate for IMD represents the percentage of reported deaths due to IMD among the reported IMD cases. Case-level CNDSS data were used to calculate IPD incidence rates for children less than two years of age and for adults 65 years of age and older.

Limitations

General limitations associated with data collected from passive surveillance systems should be considered in the interpretation of the results presented in this report, including differences in reporting practices across jurisdictions, reporting delays, missing or incomplete data, duplicate reports and under-reporting. Because surveillance activities are ongoing, all data are subject to change. Except for VPDs under elimination in Canada, cases reported to the national level are not reviewed to ensure that they meet national case definitions. Because of the unreliability of results based on small numbers, caution should be used when interpreting results such as incidence rates and sex distribution based on less than 20 cases.

Due to the passive nature of many of the surveillance systems used to provide data for this report, reported cases are expected to be underestimates of the true burden of disease. Under-reporting is also likely among adolescents and adults (who may be less likely to be seen by a health care professional) and for milder or asymptomatic illness or those diseases where laboratory confirmation of disease is infrequent. However, under-reporting of diseases is less likely to be a concern for those diseases under elimination (i.e., polio, measles, rubella and CRS/CRI) due in part to the high profile of these diseases and strong laboratory and healthcare reporting to public health.

Data for most of the surveillance systems are not received from provinces and territories in real time, nor are most cases reported at the national level linked with laboratory and epidemiological data. Outbreak surveillance data are not available nationally for any of the VPDs (except for measles, rubella, and IMD). Detailed case vaccination history, manifestations, and mortality information is not available for VPDs where data were obtained through CNDSS.

Case-level data available from CNDSS was not available for Prince Edward Island from 2001 to 2009 and for Northwest Territories, Nova Scotia, Newfoundland, New Brunswick, and Manitoba from 2001 to 2017. The populations of these jurisdictions were removed from the IPD incidence rate calculations where case-level data were used exclusively. Data from the remaining provinces and territories represents approximately 90% of the Canadian population.

As death data available through Statistics Canada has not been validated, this information was not presented in this report.

The limitations of the coverage data obtained from cNICS and The Seasonal Influenza Vaccination Coverage Survey have been documented elsewhere Footnote 19,Footnote 41.

References

Footnote 1

Public Health Agency of Canada. Brief report: Hepatitis B infection in Canada. Ottawa (ON): PHAC; 2011.; Available at: http://www.phac-aspc.gc.ca/id-mi/pdf/hepB-eng.pdf. Accessed February 20, 2017.

Return to footnote 1 referrer

Footnote 2

Ehreth J. The value of vaccination: A global perspective. Vaccine 2003;21:4105.

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Footnote 3

Centers for Disease Control and Prevention (CDC). Appendix: Methods for the cost-benefit analyses presented in "Benefits from immunization during the vaccines for children program era - United States, 1994-2013". MMWR 2014;63:352.

Return to footnote 3 referrer

Footnote 4

Public Health Agency of Canada. Poliomyelitis (polio) surveillance. Ottawa (ON): PHAC; 2014. Available at:/content/canadasite/en/public-health/services/diseases/poliomyelitis-polio/surveillance.html

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Footnote 5

Public Health Agency of Canada. Elimination of measles, rubella and congenital rubella syndrome in Canada, Documentation and Verification Report. Ottawa (ON): PHAC; 2011.

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Footnote 6

Rotondo J, Desai S, Pless R, Ahmad R, Squires S, Booth TF. Acute flaccid paralysis surveillance: The need for ruling out polio infection. Paediatrics & Child Health 2015;6:309.

Return to footnote 6 referrer

Footnote 7

Public Health Agency of Canada. Vaccination coverage goals and vaccine preventable disease reduction targets by 2025. Ottawa (ON): PHAC; 2019; Available at: /content/canadasite/en/public-health/services/immunization-vaccine-priorities/national-immunization-strategy/vaccination-coverage-goals-vaccine-preventable-diseases-reduction-targets-2025.html. Accessed 07/25, 2021.

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Footnote 8

Varughese PV, Acres SE. Measles in Canada: Surveillance summary. Can Commun Dis Rep 1979;5:121.

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Footnote 9

Varughese PV, Acres SE. Measles in Canada - 1986. CMAJ 1987;136(11):1183.

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Footnote 10

Public Health Agency of Canada. Canadian immunization guide, 7th Edition. Ottawa (ON) PHAC; 2006.

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Footnote 11

Public Health Agency of Canada. Highlights from the 2019 childhood national immunization coverage survey (cNICS). Ottawa (ON): PHAC; 2021; Available at: /content/canadasite/en/public-health/services/publications/vaccines-immunization/2019-highlights-childhood-national-immunization-coverage-survey.html. Accessed 07/05, 2021.

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Footnote 12

Macey JF, Tam T, Lipskie T, Tipples G, EisBrenner T. Rubella elimination, the Canadian experience. J Infect Dis 2011;204(suppl_2):S585.

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Footnote 13

Lim G, Harris T, Desai S, Crowcroft N, Mazzulli T, Kozlowski T, et al. Rubella immunity among prenatal women in Ontario, 2006-2010. BMC Infect Dis 2013 2 August 2013;13(362).

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Footnote 14

Lai FY, Dover DC, Lee B, Fonseca K, Solomon N, Plitt SS, et al. Determining rubella immunity in pregnant Alberta women 2009-2012. Vaccine 2015;33(5):635-641.

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Footnote 15

Gilbert N, Rotondo J, Shapiro J, Sherrard L, Fraser W, Ward B. Seroprevalence of rubella antibodies and determinants of susceptibility to rubella in a cohort of pregnant women in Canada, 2008-2011. Vaccine 2017 May 25;35(23):3050-3055.

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Footnote 16

World Health Organization. Poliomyelitis. Geneva (CH): WHO; 2019. https://www.who.int/news-room/fact-sheets/detail/poliomyelitis.

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Footnote 17

Dickson C, Fane BH, Squires SG. Acute flaccid myelitis (AFM) in Canada. Can Commun Dis Rep 2020 Oct 1;46(10).

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Footnote 18

Pan American Health Organization (PAHO). Region of the Americas eliminates maternal and neonatal tetanus. Washington (DC): PAHO; 2017; Available at: https://www.paho.org/hq/index.php?option=com_content&view=article&id=13696:americas-eliminates-maternal-neonatal-tetanus&Itemid=1926&lang=en. Accessed 07/25, 2021.

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Footnote 19

Public Health Agency of Canada. Vaccine uptake in Canadian adults. Results from the 2018-2019 Seasonal Influenza Vaccination Coverage Survey. Ottawa (ON); PHAC; 2019. /content/canadasite/en/public-health/services/publications/healthy-living/2018-2019-influenza-flu-vaccine-coverage-survey-results.html

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Footnote 20

National Advisory Committee on Immunization (NACI). Update on the invasive meningococcal disease and meningococcal vaccine conjugate recommendations. Can Commun Dis Rep 2009;35(ACS-3).

Return to footnote 20 referrer

Footnote 21

Katz SL, King K, Varughese P, De Serres G, Tipples G, Waters J, et al. Measles elimination in Canada. J Infect Dis 2004;189(S1):S236-S242.

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Footnote 22

Saboui M, Squires SG. Outbreaks of mumps in Canada, 2016-2018. Can Commun Dis Rep 2020 Nov 5;46(11/12).

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Footnote 23

Barreto L, Van Exan R, Rutty C. The challenge of whooping cough: Canada's role in the development of pertussis vaccines. 2006.

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Footnote 24

Cutcliffe N. Building on the legacy of vaccines in Canada: Value, opportunities, and challenges. Ottawa (ON); BIOTECanada: 2010.

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Footnote 25

Public Health Agency of Canada. Update on immunization in pregnancy with Tdap vaccine. An advisory committee statement (ACS). National Advisory Committee on Immunization (NACI). Ottawa (ON); PHAC: 2018.; Available at: /content/canadasite/en/public-health/services/publications/healthy-living/update-immunization-pregnancy-tdap-vaccine.html. Accessed 07/20, 2021.

Return to footnote 25 referrer

Footnote 26

Public Health Agency of Canada. Pneumococcal vaccine: Canadian immunization guide. Ottawa (ON); PHAC: 2016. /content/canadasite/en/public-health/services/publications/healthy-living/canadian-immunization-guide-part-4-active-vaccines/page-16-pneumococcal-vaccine.html

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Footnote 27

Public Health Agency of Canada. Update on the use of pneumococcal vaccines in adults 65 years of age and older - A public health perspective. An advisory committee statement (ACS). National Advisory Committee on Immunization (NACI). Ottawa (ON); PHAC: 2018; Available at: /content/canadasite/en/public-health/services/publications/healthy-living/update-on-the-use-of-pneumococcal-vaccines-in-adult.html#a6. Accessed 10/20, 2021.

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Footnote 28

National Advisory Committee on Immunization (NACI). Statement on the recommended use of pneumococcal conjugate vaccine. Can Commun Dis Rep 2002;28(ACS-2).

Return to footnote 28 referrer

Footnote 29

Kellner JD, Vanderkooi OG, MacDonald J, Church DL, Tyrrell GJ, Scheifele DW. Changing epidemiology of invasive pneumococcal disease in Canada, 1998-2007: Update from the Calgary-Area Streptococcus pneumoniae Research (CASPER) Study. Clin Infect Dis 2009;49(2):205-212.

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Footnote 30

Data was not available for British Columbia (1993 to 2017), Saskatchewan (1996 to 1997, 2001 to 2015), Manitoba (1991 to 2017), Ontario (1991 to 1992, 2009 to 2010), Quebec (1991 to 2017), Newfoundland and Labrador (2015 to 2017), Nova Scotia (1998 to 2017) and Yukon (2009 to 2012). Reporting of cases in Nunavut began in 2000. Under-reporting of varicella was noted by Ontario for their jurisdiction.

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Footnote 31

Weinberger DM, Malley R, Lipsitch M. Serotype replacement in disease after pneumococcal vaccination. The Lancet 2011;378(9807):1962-1973.

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Footnote 32

Tyrrell GJ, Lovgren M, Chui N, Minion J, Garg S, Kellner JD, et al. Serotypes and antimicrobial susceptibilities of invasive Streptococcus pneumoniae pre- and post-seven valent pneumococcal conjugate vaccine introduction in Alberta, Canada, 2000-2006. Vaccine 2009;27(27):3553-3560.

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Footnote 33

Demczuk W, Griffith A, Singh R, Martin I, Gilmour M. National Laboratory surveillance of Streptococcus pneumoniae and Streptococcus pyogenes In Canada Annual Summary 2010. 2010.

Return to footnote 33 referrer

Footnote 34

Public Health Agency of Canada (PHAC). National Surveillance of Invasive Streptococcus pneumoniae and Streptococcus pyogenes in Canada - Annual Summary 2012. Ottawa (ON); PHAC; 2013.

Return to footnote 34 referrer

Footnote 35

Public Health Agency of Canada (PHAC). National Laboratory Surveillance of Invasive Streptococcal Disease in Canada - Annual Summary 2018. Ottawa (ON); PHAC; 2019.

Return to footnote 35 referrer

Footnote 36

Squires SG, Pelletier L. Publicly-funded influenza and pneumococcal immunization programs in Canada: A progress report. Can Commun Dis Rep 2000;26(17):141.

Return to footnote 36 referrer

Footnote 37

Waye A, Jacobs P, Tan B. The impact of the universal infant varicella immunization strategy on Canadian varicella-related hospitalization rates. Vaccine 2013;31(42):4744.

Return to footnote 37 referrer

Footnote 38

Public Health Agency of Canada. Case definitions: Nationally notifiable diseases. Ottawa (ON); PHAC: 2021; Available at: https://diseases.canada.ca/notifiable/diseases-list. Accessed 06/10, 2021.

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Footnote 39

Statistics Canada. Population estimates 0-100+ October Canada - Province-Territory 1971-2020. 2021. Ottawa (ON); Stats Can: 2018.

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Footnote 40

Public Health Agency of Canada. Notifiable diseases online. Ottawa (ON); PHAC: 2020; Available at: https://diseases.canada.ca/notifiable/. Accessed 06/11, 2021.

Return to footnote 40 referrer

Footnote 41

Public Health Agency of Canada. Childhood national immunization coverage survey, 2017. Ottawa (ON); PHAC: 2019; Available at: https://www150.statcan.gc.ca/n1/daily-quotidien/190326/dq190326d-eng.htm. Accessed 06/07, 2019.

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Endnotes

Footnote 1

Diseases with programs to reduce incidence to zero - includes measles, rubella, congenital rubella syndrome/congenital rubella infection, and polio.

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Footnote 2

Annual incidence rate < 1 case per 100,000 population - includes diphtheria, tetanus, invasive disease due to Haemophilus influenzae serotype b, invasive meningococcal disease, and mumps.

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Footnote 3

Annual incidence rate ≥ 1 case per 100,000 population - includes pertussis, IPD, and varicella.

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Footnote 4

Ages were unknown for twenty-five cases and were therefore not included.

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Footnote 5

The pre-vaccine era is defined as the five years before vaccine introduction, or the closest possible five years to when stable reporting occurs. For measles, this was 1950 to 1954. The measles live vaccine was authorized in Canada in 1963 and all provinces and territories had a measles vaccine program by 1983. Measles was taken off the notifiable diseases list from 1959 to 1968 with decreased physician reporting in the years leading up to 1959, thus 1954 was chosen as the last year with reliable data that could be used in comparisons.

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Footnote 6

Measles was removed from the list of national notifiable diseases for the years 1959 to 1968 with decreased physician reporting in the years leading up to 1959.

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Footnote 7

The difference in coverage estimates in children seven years of age, between rubella, measles and mumps is due to the number of doses required to be considered vaccinated. One dose of rubella vaccine is required by seven years of age compared to two doses of measles and mumps vaccine.

Return to footnote g referrer

Footnote 8

The pre-vaccine era is defined as the five years before vaccine introduction, or the closest possible five years to when stable reporting occurs. For rubella, this was 1950 to 1954. The rubella vaccine was authorized in Canada in 1969 and all provinces and territories had a rubella vaccine program by 1983. Rubella was taken off the notifiable disease list from 1959 to 1968 with decreased physician reporting in the years leading up to 1959, thus 1954 was chosen as the last year with reliable data that could be used in comparisons.

Return to footnote h referrer

Footnote 9

Rubella was removed from the list of national notifiable diseases for the years 1959 to 1968.

Return to footnote i referrer

Footnote 10

The pre-vaccine era is defined as the five years before vaccine introduction, or the closest possible five years to when stable reporting occurs. For rubella, this was 1950 to 1954. The rubella vaccine was authorized in Canada in 1969 and all provinces and territories had a rubella vaccine program by 1983. Rubella was taken off the notifiable disease list from 1959 to 1968 with decreased physician reporting in the years leading up to 1959, thus 1954 was chosen as the last year with reliable data that could be used in comparisons.

Return to footnote j referrer

Footnote 11

The pre-vaccine era is defined as the five years before vaccine introduction, or the closest possible five years to when stable reporting occurs. For polio, this was 1950 to 1954, as the inactivated polio vaccine was authorized in Canada in 1955.

Return to footnote k referrer

Footnote 12

AFP has been nationally notifiable in Canada since 1996.

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Footnote 13

The pre-vaccine era is defined as the five years before vaccine introduction, or the closest possible five years to when stable reporting occurs. For diphtheria, this was 1925 to 1929. Although the diphtheria toxoid was introduced in 1926, routine immunization began in 1930.

Return to footnote m referrer

Footnote 14

The pre-vaccine era is defined as the five years before vaccine introduction, or the closest possible five years to when stable reporting occurs. For tetanus, this was 1935 to 1939. Tetanus toxoid was introduced in Canada in 1940 but national reporting began in 1957. Thus, reported tetanus deaths were used instead of cases for the years preceding vaccine introduction.

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Footnote 15

Tetanus was added to the list of nationally notifiable diseases in 1957. Reported tetanus deaths were used instead of cases for the years 1935 to 1956.

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Footnote 16

The pre-vaccine era used for invasive disease due to Hib was 1986 to 1987. Although Hib vaccines were first introduced in 1986 and the Hib conjugate vaccine was introduced in 1992, national notifiable disease reporting of invasive Hib disease did not begin until 1986.

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Footnote 17

Northern Canada includes Yukon, Northwest Territories, Nunavut, Quebec Cree, Quebec Nunavik and northern Labrador. Rates for the rest of Canada exclude cases reported in those six regions.

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Footnote 18

A Hib case is considered preventable if it occurs in an infant who was age-eligible to have completed the primary Hib vaccination schedule (three doses) but who was unvaccinated or under-vaccinated for age. Vaccine failures are not considered preventable.

Return to footnote r referrer

Footnote 19

The pre-vaccine era is defined as the five years before vaccine introduction, or the closest possible five years to when stable reporting occurs. For IMD, this was 1997 to 2001, as the meningococcal C conjugate vaccine was introduced in all provinces and territories between 2002 and 2007.

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Footnote 20

The "Other" category includes serogroup A, 29E, X, Z, non-groupable and unknown serogroup.

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Footnote 21

Age was unknown for one case, therefore it was not included.

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Footnote 22

The pre-vaccine era is defined as the five years before vaccine introduction, or the closest possible five years to when stable reporting occurs. For mumps, this was 1950 to 1954. The mumps vaccine was authorized in Canada in 1969 and all provinces and territories had a mumps vaccine program by 1983. Mumps was taken off the notifiable disease list from 1959 to 1985 with decreased physician reporting in the years leading up to 1959, thus 1954 was chosen as the last year with reliable data that could be used in comparisons.

Return to footnote v referrer

Footnote 23

Mumps was removed from the list of national notifiable diseases for the years 1959 to 1985.

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Footnote 24

The pre-vaccine era is defined as the five years before vaccine introduction, or the closest possible five years to when stable reporting occurs. For pertussis, this was 1938 to 1942, as the whole cell pertussis vaccine was authorized in Canada in 1943.

Return to footnote x referrer

Footnote 25

Ages were unknown for nine cases, therefore they were not included.

Return to footnote y referrer

Footnote 26

Northern Canada includes Yukon, Northwest Territories, Nunavut, Quebec Cree, Quebec Nunavik and northern Labrador. Rates for the rest of Canada exclude cases reported in those six regions.

Return to footnote z referrer

Footnote 27

Excluded 2000 because ON started reporting in 2001.

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Footnote 28

Data was not available for Prince Edward Island from 2001 to 2009 and for Northwest Territories, Nova Scotia, Newfoundland, New Brunswick, and Manitoba from 2001 to 2019. Therefore, the population for these provinces and territories were excluded in the calculation on incidences rates for children less than two years of age and adults 65 years of age and over, depending on the corresponding year.

Return to footnote ab referrer

Footnote 29

The pre-vaccine era is defined as the five years before vaccine introduction, or the closest possible five years to when stable reporting occurs. For varicella, this was 1993 to 1997, as the first varicella vaccine was approved for use in Canada in 1998.

Return to footnote ac referrer

Footnote 30

Data was not available for British Columbia (1993 to 2017), Saskatchewan (1996 to 1997, 2001 to 2015), Manitoba (1991 to 2017), Ontario (1991 to 1992, 2009 to 2010), Quebec (1991 to 2017), Newfoundland and Labrador (2015 to 2017), Nova Scotia (1998 to 2017) and Yukon (2009 to 2012). Reporting of cases in Nunavut began in 2000. Under-reporting of varicella was noted by Ontario for their jurisdiction.

Return to footnote ad referrer

Footnote 31

Ages were unknown for two cases and were therefore not included.

Return to footnote ae referrer

Footnote 32

Vaccine eligible children include children aged one to 17 who are not immunocompromised and are either not vaccinated or have an unknown vaccination status for varicella.

Return to footnote af referrer

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