Summary of NACI statement of July 25, 2024: Supplemental guidance on influenza vaccination in adults 65 years of age and older

On this page

• Overview
• What you need to know

Overview

• Adults 65 years of age and older are at higher risk of influenza complications, such as hospitalization and death. As a result, seasonal influenza immunization is particularly important for this group.
• On July 25, 2024, the Public Health Agency of Canada (PHAC) released the National Advisory Committee on Immunization's (NACI) Supplemental guidance on influenza vaccination in adults 65 years of age and older. This guidance is based on current evidence and NACI expert opinion.
• In Canada, there are several influenza vaccines authorized and available for use in adults 65 years of age and older:
  • Standard dose inactivated influenza vaccines (most are grown in egg, one grown in cell culture)
  • High dose inactivated influenza vaccine (contains 4 times the amount of hemagglutinin antigen compared to the standard dose vaccine. Hemagglutinin antigen is a part of the influenza virus. Presenting it this way helps the body's defense system recognize and fight off the virus more effectively)
  • Recombinant influenza vaccine (contains 3 times the amount of hemagglutinin antigen compared to the standard dose vaccine)
  • Adjuvanted inactivated influenza vaccine (contains the same amount of hemagglutinin antigen as the standard dose vaccine but also contains adjuvant, a substance that improves the body's response to the vaccine)
• Following an updated evidence review, NACI concluded that high-dose inactivated influenza vaccine, adjuvanted inactivated influenza vaccine and recombinant influenza vaccine offer increased benefits for adults 65 years of age and older when compared to standard dose influenza vaccines. The high-dose vaccine has the most supporting evidence, followed by the adjuvanted vaccine, and then recombinant vaccine. However, at this point there is not enough evidence to compare between these enhanced vaccines.
• Following a thorough review of the complete body of evidence:
  • NACI recommends that high-dose inactivated influenza vaccine, adjuvanted inactivated influenza vaccine, or recombinant influenza vaccine should be offered over other influenza vaccines for adults 65 years of age and older. If a preferred product is not available, any of the available age-appropriate influenza vaccine should be offered.
  • NACI also continues to strongly recommend the inclusion of adults 65 years of age and older among those for whom it is particularly important to receive influenza vaccination.

NACI will continue to monitor the evolving evidence related to influenza vaccines in older adults and will update guidance as needed.

For the full statement, including supporting evidence and rationale, please see NACI's Supplemental guidance on influenza vaccination in adults 65 years of age and older.

For a full list of people for whom influenza vaccination is particularly important, please see Priority Groups for Influenza Vaccination in the NACI Statement on Seasonal Influenza Vaccine for 2024-2025.

What you need to know

• Adults 65 years of age and older are at higher risk of influenza complications, such as hospitalization, ICU admission, and death. A seasonal influenza vaccine is one of the best ways to prevent influenza and its complications.
• The immune system changes with age and this can make it harder for the body to fight off infections and effectively respond to vaccines. Influenza vaccines made using newer technology, such as higher doses and adjuvants, have been targeted toward older adults with the aim to improve vaccine effectiveness and provide enhanced protection in this population.
• NACI has conducted several reviews over the years to evaluate the available information on how well the vaccines work and cost-effectiveness evidence to ensure recommendations for adults aged 65 years and older are up to date. These recommendations have evolved over time due to the availability of new vaccine products and expanding evidence on the performance of influenza vaccines.
• NACI is now recommending that the high-dose, adjuvanted or recombinant influenza vaccines should ideally be used instead of the standard dose influenza vaccines for adults 65 years of age and over. There have not been enough studies to determine whether any vaccine among these three is superior to the others. The most evidence exists for the high-dose vaccine.
• When supplies of high-dose, adjuvanted and recombinant influenza vaccines are limited, priority should be given to people at highest risk of severe influenza outcomes, including those 75 years of age and over, those with comorbidities, frail older adults, and residents of nursing homes and other chronic care facilities.
• All of the authorized vaccines for adults 65 years of age and over have a proven safety record.
• The cost to purchase all enhanced influenza vaccines is usually higher than standard dose influenza vaccines. Canadian provinces and territories will decide which vaccine is the best fit for their seasonal influenza programs, considering their epidemiology, clinical impacts, and costs.
• Any seasonal influenza vaccine may be given at the same time as, or any time before or after administration of other vaccines, including COVID-19 vaccines, for those aged 6 months and older.
• To determine which vaccine is available in your Province or Territory, and to determine where the vaccine is offered, please talk to a healthcare provider or local public health authority.

For more information on NACI recommendations related to seasonal influenza vaccination, please see the Canadian Immunization Guide chapter on influenza, as well as additional statements on the NACI web page.