22 Oct Flu Mutations Led To More Disease Among Middle-Aged Adults
Medical Research: What are the main findings of the study?
Dr. Hensley: We found that H1N1 viruses recently acquired a mutation that abrogates binding of influenza antibodies that are present in a large number of middle-aged adults. We propose that this mutation lead to increased disease among middle-aged adults during the 2013-2014 influenza season.
Medical Research: What was most surprising about the results?
Dr. Hensley: We were surprised this antigenic H1N1 mutation has been largely overlooked and that most surveillance laboratories have labeled this mutation as ‘antigenically neutral’. Most influenza antigenic studies utilize animal anti-sera, which fails to recapitulate the types of antibodies that are present in some humans.
Medical Research: What should clinicians and patients take away from your report?
Dr. Hensley: We identified an antibody signature that is present in some middle-aged individuals and we propose that this type of antibody does not proper fight off recently mutated influenza strains. At this point, our human studies are correlative in nature, and the overall contribution of this type of antibody to influenza susceptibility still needs to be determined. Without a doubt, patients should continue to receive the seasonal influenza vaccine this year. Studies have shown that the current vaccine formulation is effective.
Medical Research: What recommendations do you have for future research as a result of this study?
Dr. Hensley: Each year surveillance laboratories make suggestions for which influenza strains to include in the seasonal vaccine. Our current work is focused on creating reference animal anti-sera that is representative of human immunity. This type of anti-sera could potentially be useful when deciding which vaccine strains to include in the seasonal influenza vaccine each year.
Potential antigenic explanation for atypical H1N1 infections among middle-aged adults during the 2013–2014 influenza season
Susanne L. Linderman, Benjamin S. Chambers, Seth J. Zost, Kaela Parkhouse, Yang Li, Christin Herrmann, Ali H. Ellebedy, Donald M. Carter, Sarah F. Andrews, Nai-Ying Zheng, Min Huang, Yunping Huang, Donna Strauss, Beth H. Shaz, Richard L. Hodinka, Gustavo Reyes-Terán, Ted M. Ross, Patrick C. Wilson, Rafi Ahmed, Jesse D. Bloom, and Scott E. Hensley
PNAS 2014 ; published ahead of print October 20, 2014, doi:10.1073/pnas.1409171111