Hemagglutinin Gene Clade 3C.2a Influenza A(H3N2) Viruses, Alachua County, Florida, USA, 2014–15

John A. Lednicky, Nicole M. Iovine, Joe Brew, Julia C. Loeb, Jonathan D. Sugimoto, Kenneth H. Rand, J. Glenn Morris

Emerging Infectious Diseases

January 29, 2016


Influenza A(H3N2) strains isolated during 2014–15 in Alachua County, Florida, USA, belonged to hemagglutinin gene clade 3C.2a. High rates of influenza-like illness and confirmed influenza cases in children were associated with a decrease in estimated vaccine effectiveness. Illnesses were milder than in 2013–14; severe cases were concentrated in elderly patients with underlying diseases.