Influenza (Flu) and Viral Respiratory Tract Infection ...

Influenza A viruses can be classified into subtypes according to combinations of these H and N proteins. The influenza A subtypes currently circulating among humans are influenza A(H1N1) and influenza A(H3N2). Although influenza B possesses H and N proteins, they belong to one of the two lineages: Yamagata or Victoria. ................
................