A Pyrosequencing-Based Approach to High-Throughput Identification of Influenza A(H3N2) Virus Clades Harboring Antigenic Drift Variants.

The rapid evolution of influenza A(H3N2) viruses necessitates close monitoring of their antigenic properties so the emergence and spread of antigenic drift variants can be rapidly identified. Changes in hemagglutinin (HA) acquired by contemporary A(H3N2) viruses hinder antigenic characterization by traditional methods, thus complicating vaccine strain selection. Sequence-based approaches have been used to infer virus antigenicity; however, they are time consuming and mid-throughput.