@article{4b8f6fbc13634558b82a1a8a51e7d385,
title = "Sex-specific effects of aging on humoral immune responses to repeated influenza vaccination in older adults",
abstract = "Older adults (≥65 years of age) bear a significant burden of severe disease and mortality associated with influenza, despite relatively high annual vaccination coverage and substantial pre-existing immunity to influenza. To test the hypothesis that host factors, including age and sex, play a role in determining the effect of repeated vaccination and levels of pre-existing humoral immunity to influenza, we evaluated pre- and post-vaccination strain-specific hemagglutination inhibition (HAI) titers in adults over 75 years of age who received a high-dose influenza vaccine in at least four out of six influenza seasons. Pre-vaccination titers, rather than host factors and repeated vaccination were significantly associated with post-vaccination HAI titer outcomes, and displayed an age-by-sex interaction. Pre-vaccination titers to H1N1 remained constant with age. Titers to H3N2 and influenza B viruses decreased substantially with age in males, whereas titers in females remained constant with age. Our findings highlight the importance of pre-existing immunity in this highly vaccinated older adult population and suggest that older males are particularly vulnerable to reduced pre-existing humoral immunity to influenza.",
author = "Shapiro, {Janna R.} and Huifen Li and Rosemary Morgan and Yiyin Chen and Helen Kuo and Xiaoxuan Ning and Patrick Shea and Cunjin Wu and Katherine Merport and Rayna Saldanha and Suifeng Liu and Engle Abrams and Yan Chen and Kelly, {Denise C.} and Eileen Sheridan-Malone and Lan Wang and Zeger, {Scott L.} and Klein, {Sabra L.} and Leng, {Sean X.}",
note = "Funding Information: The authors thank the participants, as well as the clinical staff at the Healthy Aging Studies Unit and the Johns Hopkins University Institute for Clinical and Translational Research. The authors would also like to than Dr. Andrew Pekosz for helpful discussion and feedback. Sanofi Pasteur provided HD-IIV3 and performed HAI testing, but remained blinded to the results and had no further scientific input. This work was supported in part by National Institute of Health (NIH)/National Institute of Allergy and Infectious Diseases R01 AI108907 to S.X.L., NIH/National Institute on Aging Specialized Center of Research Excellence U54 AG062333 awarded to S.L.K. and funding from Irma and Paul Milstein Program for Senior Health, Milstein Medical Asian American Partnership (MMAAP) Foundation of USA to S.X.L., J.R.S was supported by a training award from the Fonds de recherche du Qu{\'e}bec – Sant{\'e} (File #287609). C.J.W, X.X.N. and S.F.L. were supported by Irma and Paul Milstein Program for Senior Health fellowship awards from MMAAP Foundation of USA (www. mmaapf.org). Publisher Copyright: {\textcopyright} 2021, The Author(s).",
year = "2021",
month = dec,
doi = "10.1038/s41541-021-00412-6",
language = "English (US)",
volume = "6",
journal = "npj Vaccines",
issn = "2059-0105",
publisher = "Nature Publishing Group",
number = "1",
}