Penn Study Pinpoints H3N2 Mutation in Last Year’s Flu Vaccine as Responsible for Lowered Efficacy
November 6, 2017
The low efficacy of last year’s influenza vaccine can be attributed to a mutation in the H3N2 strain of the virus, a new study reports. Due to the mutation, most people receiving the egg-grown vaccine did not have immunity against H3N2 viruses that circulated last year, leaving the vaccine with only about 30 percent effectiveness. Scott Hensley, PhD, an associate professor of Microbiology, in the Perelman School of Medicine at the University of Pennsylvania, describes his team’s findings in the Proceedings of the National Academy of Sciences this week.