Highlights
– Pfizer’s modified nucleoside mRNA quadrivalent influenza vaccine showed a statistically superior relative efficacy of 34.5% (95% CI 7.4–53.9) versus a licensed inactivated quadrivalent vaccine in adults 18–64 years during the 2022–2023 season.
– Efficacy and HAI noninferiority were demonstrated for influenza A/H3N2 and A/H1N1 strains but not for influenza B strains; most cases in the trial were A strains.
