Genomic and antigenic evolution of influenza A(H3N2) after the COVID-19 era: a scoping review with focus on J and K subclades and implications for vaccine effectiveness

The objective of this scoping review is to systematically map and synthesize the available evidence on the post-pandemic genomic and antigenic evolution of influenza A(H3N2), with particular focus on emerging antigenic drift variants, including those later designated as subclade K (J.2.4.1), and their implications for vaccine effectiveness and public health preparedness.