Mismatched H3N2 and influenza A viruses have been widespread during the 2014 to 2015 flu season. While H3N2 influenza is predominant this season, H1N1 and influenza B viruses are also circulating, reports the Centers for Disease Control and Prevention.
The flu virus that is currently predominant is a drifted strain of the H3N2 influenza virus. A drifted virus has evolved from previously circulating human influenza viruses. The flu vaccination for the 2014 to 2015 season does not contain the drifted forms of the H3N2 virus, but it does still protect against H1N1 and influenza B, according to the CDC.
The H3N2 strain of the flu hits children and people ages 65 and older the hardest. The 2015 rate of flu-related hospitalizations for older people is at its highest since 2005, with 60 percent of flu-related hospitalizations being in people 65 and older. Children ages 0 to 4 have the second-highest hospitalization rate this season, states the CDC.
Flu vaccines usually protect from the flu viruses that research states should be predominant for that season. For protection from the flu, the CDC recommends an annual flu vaccine for everyone over 6 months old. Additionally, consistent hand-washing and avoidance of sick people provides protection from the flu.