Influenza A virus subtype H3N2 (
A/H3N2) is a subtype of
viruses that causes
influenza (flu). H3N2
Viruses can infect birds and mammals. In birds, humans, and
pigs, the virus has
mutated into many strains. H3N2 is increasingly abundant in
seasonal influenza, which kills an estimated 36,000 people in the United States each year.