Interim estimates of 2019/20 vaccine effectiveness during early-season co-circulation of influenza A and B viruses, Canada, February 2020

Euro Surveill. 2020 Feb;25(7):2000103. doi: 10.2807/1560-7917.ES.2020.25.7.2000103.

Abstract

Interim results from Canada's Sentinel Practitioner Surveillance Network show that during a season characterised by early co-circulation of influenza A and B viruses, the 2019/20 influenza vaccine has provided substantial protection against medically-attended influenza illness. Adjusted VE overall was 58% (95% confidence interval (CI): 47 to 66): 44% (95% CI: 26 to 58) for A(H1N1)pdm09, 62% (95% CI: 37 to 77) for A(H3N2) and 69% (95% CI: 57 to 77) for influenza B viruses, predominantly B/Victoria lineage.

Keywords: antigenic match; clade; genetic sequencing; influenza; vaccine effectiveness.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Antigens, Viral / analysis
  • Canada / epidemiology
  • Child
  • Child, Preschool
  • Female
  • Genotype
  • Hemagglutination Inhibition Tests
  • Humans
  • Infant
  • Influenza A Virus, H1N1 Subtype / genetics
  • Influenza A Virus, H1N1 Subtype / immunology
  • Influenza A Virus, H1N1 Subtype / isolation & purification*
  • Influenza A Virus, H3N2 Subtype / genetics
  • Influenza A Virus, H3N2 Subtype / immunology
  • Influenza A Virus, H3N2 Subtype / isolation & purification*
  • Influenza B virus / genetics
  • Influenza B virus / immunology
  • Influenza B virus / isolation & purification*
  • Influenza Vaccines / administration & dosage*
  • Influenza Vaccines / immunology
  • Influenza, Human / epidemiology*
  • Influenza, Human / prevention & control*
  • Male
  • Middle Aged
  • Molecular Sequence Data
  • Nasopharynx / virology
  • Nose / virology
  • Real-Time Polymerase Chain Reaction
  • Seasons
  • Sentinel Surveillance
  • Sequence Analysis, DNA
  • Young Adult

Substances

  • Antigens, Viral
  • Influenza Vaccines