Low 2016/17 season vaccine effectiveness against hospitalised influenza A(H3N2) among elderly: awareness warranted for 2017/18 season

Euro Surveill. 2017 Oct;22(41):17-00645. doi: 10.2807/1560-7917.ES.2017.22.41.17-00645.

Abstract

In a multicentre European hospital study we measured influenza vaccine effectiveness (IVE) against A(H3N2) in 2016/17. Adjusted IVE was 17% (95% confidence interval (CI): 1 to 31) overall; 25% (95% CI: 2 to 43) among 65-79-year-olds and 13% (95% CI: -15 to 30) among those ≥ 80 years. As the A(H3N2) vaccine component has not changed for 2017/18, physicians and public health experts should be aware that IVE could be low where A(H3N2) viruses predominate.

Keywords: A(H3N2); Influenza; cases control; elderly; hospitalisation; vaccine effectiveness.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • European Union
  • Female
  • Hospitalization / statistics & numerical data*
  • Hospitals
  • Humans
  • Influenza A Virus, H3N2 Subtype / immunology
  • Influenza A Virus, H3N2 Subtype / isolation & purification
  • Influenza Vaccines / immunology*
  • Influenza, Human / epidemiology
  • Influenza, Human / prevention & control*
  • Influenza, Human / virology
  • Male
  • Middle Aged
  • Outcome Assessment, Health Care
  • Seasons

Substances

  • Influenza Vaccines