Relative Vaccine Effectiveness of Adjuvanted Quadrivalent Inactivated Influenza Vaccine (aIIV4) vs High-Dose Quadrivalent Inactivated Influenza Vaccine (HD-IIV4) for Prevention of Lab-confirmed Influenza Medical Encounters
In this study, each objective will be evaluated for each season individually and in a combined analysis. The primary objective is to assess the relative vaccine effectiveness of aIIV4 vs HD-IIV4 for prevention of polymerase-chain reaction (PCR) confirmed influenza. The…