Influenza vaccine effectiveness in Europe and the birth cohort effect against influenza A(H1N1)pdm09: VEBIS primary care multicentre study, 2023/24.

ABSTRACT: IntroductionInfluenza A(H1N1)pdm09, A(H3N2) and B/Victoria viruses circulated in Europe in 2023/24, with A(H1N1)pdm09 dominance. First influenza infections in childhood may lead to different vaccine effectiveness (VE) in subsequent years.AimThe VEBIS primary care network estimated influenza VE in Europe using a multicentre test-negative study.MethodsPrimary care practitioners collected information and specimens from patients consulting with acute respiratory infection. We estimated VE against influenza (sub)type and clade, by age group and by year of age for A(H1N1)pdm09, using logistic regression.ResultsWe included 29,958 patients, with 3,054, 1,053 and 311 influenza A(H1N1)pdm09, A(H3N2) and B cases, respectively. All-age VE against influenza A(H1N1)pdm09 was 52% (95% CI: 44-59). By year

SUBMITTER: Kissling E 

PROVIDER: S-EPMC12164280 | biostudies-literature | 2025 Jun

REPOSITORIES: biostudies-literature