Literature Review Update on the Efficacy and Effectiveness of High-Dose (Fluzone® High-Dose) and MF59-Adjuvanted (Fluad®) Trivalent Inactivated Influenza Vaccines in Adults 65 Years of Age and Older

Executive Summary

Two trivalent inactivated influenza vaccines (TIVs) designed specifically for adults 65 years of age and older are currently authorized for use in Canada: a high-dose vaccine (Fluzone^® High-Dose, Sanofi Pasteur) and an MF59-adjuvanted vaccine (Fluad^®, Seqirus). Previous literature reviews on the efficacy and effectiveness, immunogenicity and safety of Fluzone^® High-Dose and Fluad^® have been conducted to inform NACI’s recommendations on the use of these vaccines in the annual NACI Advisory Committee Statement: Canadian Immunization Guide Chapter on Influenza and Statement on Seasonal Influenza Vaccine. To ensure that these recommendations continue to be informed with the most current literature, the present literature review was conducted to identify additional efficacy and effectiveness evidence published since the original literature reviews. Five additional studies regarding Fluzone^® High-Dose and four additional studies regarding Fluad^® were identified, all of which assessed vaccine effectiveness for the two vaccines. Several methodological concerns were identified that warrant cautious interpretation of study findings for both vaccines. In consideration of these concerns, the present literature review update did not identify evidence that warrants changing the conclusions of the previous reviews and concludes that: 1) there is good evidence that Fluzone^® High-Dose provides superior protection compared with standard-dose TIV in the elderly (Grade A Evidence); 2) there is fair evidence that the MF59-adjuvanted Fluad^® may be effective at reducing the risk of hospitalization for influenza and influenza complications in the elderly compared to unvaccinated individuals (Grade B Evidence); 3) there is insufficient evidence that Fluad^® is effective at reducing the risk of hospitalization for influenza and influenza complications in the elderly compared to those who received unadjuvanted trivalent inactivated subunit vaccine (Grade I Evidence); and 4) there is no identified evidence on how the high-dose vaccine directly compares to the MF59-adjuvanted vaccine (Grade I Evidence).

The literature review is available through the Government of Canada Publications website. To obtain the report in an alternative format, please contact us by email: phac.naci-ccni.aspc@canada.ca.