Adverse Events Following Immunization (AEFI) Quarterly Report for 2015 – Q3
Safety Assessment Summary for Quarter 3:
- No vaccine safety signals were identified in Quarter 3 of 2015.
- This report presents 401 AEFI reports received from provincial or territorial jurisdictions during Q3.
- Additionally during this quarter, one jurisdiction submitted historical data comprising 2,126 AEFI reports. Technical reasons had prevented them from transmitting the data to the national AEFI database. Nevertheless, this jurisdiction had been monitoring these case reports and had concerns arisen, would have discussed these through the Vaccine Vigilance Working GroupFootnote 1.
Vaccines are closely monitored in Canada at all phases of the vaccine product ‘life cycle’ from discovery through market authorization (pre-market) and beyond, as people begin using them (post-market). Many stakeholders are involved in various activities related to vaccine safety assessment and monitoring including the federal government, provincial, territorial and local public health authorities, health care providers, vaccine industry and the public. The Public Health Agency of Canada (the Agency) conducts vigilant post-market safety surveillance through a national reporting system, the Canadian Adverse Events Following Immunization Surveillance System (CAEFISS).
An AEFI is defined as any untoward medical occurrence which follows immunization and which does not necessarily have a causal relationship with the usage of the vaccine. The adverse event may be any unfavourable or unintended sign, abnormal laboratory finding, symptom or disease. Serious AEFIs are those which are life-threatening, result in hospitalization or a prolongation of hospitalization, result in persistent or significant disability, or where the outcome is a birth defect or death. Reports not meeting the serious event's definition are classified as non-serious.
The primary purpose of vaccine post market surveillance is to detect safety concerns. These concerns include a possible increase in the severity or frequency of expected AEFIs, or occurrence of one or more unexpected events (i.e. an event that is not consistent with Canadian product information or labelling). This allows immunization providers and public health immunization program providers to take public health action at the level of the:
- individual (such as further investigations to confirm a diagnosis and determine possible causes, consultation to rule out allergy to one or more vaccine components, or evaluate whether or not to give subsequent doses of a vaccine), and/or
- immunization program (such as investigation of a cluster of adverse events, review of procedures to ensure that vaccine storage requirements have been strictly followed, or consideration of a change in policy to adopt a less reactogenic vaccine).
The Agency also shares AEFI data with Health Canada’s Health Products and Foods Branch, the national regulatory authority for vaccines in Canada. This enables more formal action related to vaccines marketed in Canada to take place if needed. These actions may include issuing communications to immunization providers or the public regarding the safety concern or requiring additional information or investigation by the vaccine distributor, or changes to the product labeling.
Vaccine safety surveillance reports summarizing CAEFISS data are released by the Agency on a routine basis. The Quarterly Reports summarize all AEFI reports received by the Agency from January to March (Quarter 1), April to June (Quarter 2), July to September (Quarter 3) and October to December (Quarter 4), regardless of the date the vaccine was given.
In order to provide a general idea of how the data may vary from year to year, each quarter’s data are shown along with an average of the preceding prior years’ quarterly data (in other words, the data in this quarter, Quarter 3, are shown along with the average Quarter 3 data from previous 4 years). However, because these data reflect reports received in the particular quarter, and not necessarily when the vaccine was given, they can be subject to wide variations depending on when and how reports are received, processed and forwarded by provincial/territorial public health authorities. Therefore the ability to compare and interpret patterns in these data is limited and the purpose of this report is to provide only a data snapshot.
Notes on interpretation: AEFI reports submitted to the Public Health Agency of Canada represent a suspicion, opinion or observation by the reporter as opposed to an assertion or proof that the vaccine may have caused the event. Additional limitations to AEFI report data include varied reporting standards and underreporting, lack of certainty regarding the diagnostic validity of a reported event, missing information regarding other potential causes, and other reporting biases.
Results Highlighted for Quarter 3 of 2015
Counts included in this Quarterly Report (Q3) include AEFI case reports routinely received from July 1st to September 30th, 2015 and comparisons are made to the average number of reports received in the same quarter over the previous four calendar years (2011-2014). The reports analysed were extracted from the CAEFISS database on January 5th, 2016 by the Public Health Agency of Canada (the Agency).
All reports are coded with a main reason for reporting, meaning that if more than one event is described, the one that led to reporting is coded the primary. In addition, all those describing a serious event were reviewed and unless highlighted in this report, found either to be expected (based on known vaccine-related adverse reactions) or to have alternate explanations not related to vaccination.
During Q3, one jurisdiction sent data that had been omitted from routine transmissions due to a technical issue. These case reports, not included in the main text analysis, are summarized in the text-box below:
Retrospective cases received during Q3:
- Total of 2,164 reports
- Vaccines administered between 2001 and 2015
- Proportion of serious reports: 4% (N=98)
- Mean age of cases: 22 years old (median: 14) at time of immunization.
- The most frequently reported events were vaccination site reactions (N=508) and allergic or allergic-like reactions (N=455).
Number of AEFI and Serious AEFI Reports
A total of 401 AEFI reports were received by the Agency in Q3 of 2015. During Quarter 3 of 2011, 2012, 2013 and 2014 the Agency received an average of 619 (range: 444-854) reports [Figure 1].
A total of 36 AEFI reports received by the Agency in Q3 of 2015 were classified as serious (9% of all AEFI reports). During Quarter 3 for 2011, 2012, 2013 and 2014 the Agency received an average of 51 (range: 44-64) serious AEFI reports (6.7 to 10.2% of all AEFI reports).
Frequency of Serious and Non-serious AEFI Reports by Age Group
Table 1 shows the number of serious and non-serious AEFI reports by age group in Q3 of 2015 and comparison with 2011-2014 average. Regardless of seriousness, numbers were the same or smaller in Q3 of 2015 compared to 2011-2014 average. This could be explained by missing data from one jurisdiction in 2015.
|Age Group||Serious reports||Non-serious reports|
AEFIs by Major Classification
Figure 2 presents the main types of AEFIs (both serious and non-serious) reported during Q3.
The main types of AEFI reported by level of seriousness for Q3 of 2015 compared to the 2011-2014 average is shown in Table 2. In Q3 of 2015 as well as in the past 4 years, reactions at or near the vaccination site and rashes were the main AEFIs reported for non-serious cases and neurologic events (which are most often seizures triggered by fever) followed by systemic events (i.e. events involving many body systems often accompanied by fever), were the most frequent serious AEFIs.
|Primary AEFI event reportedTable 2 - Footnote *||Serious reports||Non-serious reports|
|Reaction at or near the vaccination site||2||5||161||133|
|Allergic or allergic-like event||1||2||33||56|
|Arthritis, HHE, intussusception, para/anesthesia, parotitis, persistent crying, and thrombocytopenia||1||9||12||24|
|Other eventTable 2 - Footnote **||6||4||34||35|
|Vaccination error without an associated AEFI||0||0||0||12|
Vaccines administered in AEFI Reports
Table 3 lists the most commonly administered vaccines among AEFI reports received for Quarter 3 of 2015.
|Vaccines administered||Serious reports||Non-serious reports|
|1. DTaP booster||0||2||7||43|
|2. DTaP infant series||19||18||78||128|
|3. Hepatitis B||3||1||37||40|
|4. Human papillomavirus (HPV)||2||1||23||27|
|6. Measles, mumps, rubella, varicella
(MMRV and MMR + V)
|8. Other vaccines||0||5||13||85|
|11. Tdap booster||1||2||54||75|
|12. Travel vaccines||2||2||30||69|
|13. Zoster virus||0||1||33||18|
This Quarter 3 report for 2015 is based on reports of adverse events received at the Agency from provincial/territorial public health authorities and active, pediatric hospital based surveillance. Detailed evaluation of the reports and reporting patterns in collaboration with provincial/territorial vaccine safety focal points on the VVWG and Health Canada have not identified any vaccine safety signals of concern. The tables and figures in this report provide a snapshot of the data reviewed and provide an overview of adverse event reporting in Canada.
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