Exact strain matching is not essential for public health benefit.

  • Evidence from recent seasons shows that vaccines targeting closely related variants have delivered similar real-world effectiveness, even when the specific targeted strain was no longer dominant by the time of peak circulation (Sharff et al., Vaccine 2025).

  • For example, vaccines targeting JN.1- and KP.2-lineage variants showed comparable protection, despite rapid changes in circulating strains during the season (Sharff et al., Vaccine 2025; Laniece Delaunay et al., 2025).

  • Broad, lineage-level vaccine updates that prioritise cross-protection, rather than precise strain matching, may therefore offer more robust and reliable population-level protection (Sharff et al., Vaccine 2025).

  1. Laniece Delaunay C, et al. COVID-19 Vaccine Effectiveness Against Medically Attended Symptomatic SARS-CoV-2 Infection Among Target Groups in Europe, October 2024–January 2025, VEBIS Primary Care Network. Influenza and Other Respiratory Viruses. 2025;19(11):e70120.

  2. Sharff KA, Haslam A, Nealon J. COVID-19 vaccine variant target: how should we choose? Vaccine. 2025;68:127917.