Comparative Effectiveness of Influenza Vaccines Among US Medicare Beneficiaries Ages 65 Years and Older During the 2019–2020 Season

Abstract

In this influenza B-Victoria and A(H1N1)-dominated season, RIV4 was moderately more effective than other vaccines, while HD-IIV3 and aIIV3 were more effective than the IIV4 vaccines, highlighting the contributions of antigen amount and adjuvant use to VE. Egg adaptation likely did not substantially affect our RVE evaluation. Our findings, specific to the 2019-2020 season, should be evaluated in other studies using virological case confirmation.