Vaccine effectiveness against influenza hospitalisation in adults during the 2022/2023 mixed season of influenza A(H1N1)pdm09, A(H3N2) and B circulation, Europe: VEBIS SARI VE hospital network

Influenza Other Respir Viruses. 2024 Feb;18(2):e13255. doi: 10.1111/irv.13255.

Abstract

We conducted a multicentre hospital-based test-negative case-control study to measure vaccine effectiveness (VE) against PCR-confirmed influenza in adult patients with severe acute respiratory infection (SARI) during the 2022/2023 influenza season in Europe. Among 5547 SARI patients ≥18 years, 2963 (53%) were vaccinated against influenza. Overall VE against influenza A(H1N1)pdm09 was 11% (95% CI: -23-36); 20% (95% CI: -4-39) against A(H3N2) and 56% (95% CI: 22-75) against B. During the 2022/2023 season, while VE against hospitalisation with influenza B was >55%, it was ≤20% for influenza A subtypes. While influenza vaccination should be a priority for future seasons, improved vaccines against influenza are needed.

Keywords: SARI patients; hospital; influenza; test-negative design; vaccine effectiveness.

MeSH terms

  • Adult
  • Case-Control Studies
  • Europe / epidemiology
  • Hospitalization
  • Hospitals
  • Humans
  • Influenza A Virus, H1N1 Subtype* / genetics
  • Influenza A Virus, H3N2 Subtype / genetics
  • Influenza Vaccines*
  • Influenza, Human* / epidemiology
  • Influenza, Human* / prevention & control
  • Pneumonia*
  • Seasons
  • Vaccination
  • Vaccine Efficacy

Substances

  • Influenza Vaccines