Molecular and antigenic evolution of human influenza A/H3N2 viruses in Quebec, Canada, 2009–2011

Genetic mutations in influenza H3N2 viruses from a 2012 epidemic in Southern China

“…These mutations included V112I at site E, K173 E at site D and N278K at site C. These mutations possibly result in a conformational change to the HA molecule, thereby exposing novel epitopes and thus abrogating the binding of pre-existing antibodies at these sites. A Canadian study in 2011 involving antigenic and molecular characterization of H3N2 viruses over three seasons revealed that the number of HA mutations was important, along with the nature and location of key mutations, and played a significant role in antigenic drift [5]. From our findings, presented in this report, the 2012 strains had evolved genetically and antigenically from the A/Perth/16/2009 vaccine-like strains.…”

“…In Canada, antigenic drift was observed in 2008 when the A/Brisbane/10/2007 strain (the vaccine strain used in 2008–2009 and 2009–2010) mutated into the A/Perth/16/2009 strain (vaccine strain used in 2010–2011) [5]. Antigenic and molecular characterization of H3N2 viruses over those three seasons revealed that the number of HA mutations is important, along with the nature and location of key mutations, and likely plays a significant role in antigenic drift.…”

Characterization of Drug-Resistant Influenza Virus A(H1N1) and A(H3N2) Variants SelectedIn Vitrowith Laninamivir

“…We selected another substitution of interest in the A(H3N2) virus antigenic site A, the N144K HA substitution. This amino acid change is present along with others (E62K, K158N, K173Q, and N189K) in a drifted strain that emerged in 2009 (39,40).…”

Phylodynamics of influenza A(H3N2) in South America, 1999–2012

“…Influenza A subtype H3N2 has been circulating since 1968 in human populations . The substantial human morbidity and mortality due to annual influenza A(H3N2) epidemics during the years 2003 and 2004 (Ghedin et al, 2005), as well as the rise of a new reassortant influenza A(H3N2) variant in the human population in 2011 (Lindstrom et al, 2012), demonstrate the evolutionary plasticity of this subtype and its ability to cause extensive and major epidemics (Ann et al, 2012).…”