Vaccination accelerates the race of influenza virus against collective immunity.

Vaccination may accelerate influenza virus evolution and increase infection incidence unless specific conditions are met.

• Why it matters: Understanding how vaccines influence viral evolution is crucial for designing effective immunization strategies against rapidly evolving respiratory viruses like influenza.
• What they did: A coupled epidemiological and multi-locus evolution model, informed by influenza data, analyzed the effects of overlapping and non-overlapping vaccinations on viral evolution.
• The result: Findings suggest that vaccination accelerates viral evolution and may raise infection rates unless vaccine-induced antibodies are more broadly neutralizing or the vaccine vector slightly leads the dominant virus variant.