Age-specific incidence of influenza A responds to change in virus subtype dominance


When H3N2 replaced H1N1 as the dominant influenza subtype during the 2018-19 season, the pattern of age-specific influenza incidence shifted due to the lingering effects of antigenic imprinting. The characteristic shape that imprinting leaves on influenza susceptibility could foster important advances in understanding and predicting the epidemiology of influenza.