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Earliest infections predict the age distribution of seasonal influenza A cases
Huong Q. McLean
Edward A. Belongia
Sarah Cobey
Philip Arevalo
Novel Coronavirus
Acceso Abierto
Seasonal variation in the age distribution of influenza A cases suggests that factors other than age shape susceptibility to medically attended infection. We ask whether these differences can be partly explained by protection conferred by childhood influenza infection, which has lasting impacts on immune responses to influenza and protection against new influenza A subtypes (phenomena known as original antigenic sin and immune imprinting). Fitting a statistical model to data from studies of influenza vaccine effectiveness (VE), we find that primary infection appears to reduce the risk of medically attended infection with that subtype throughout life. This effect is stronger for H1N1 compared to H3N2. Additionally, we find evidence that VE varies with both age and birth year, suggesting that VE is sensitive to early exposures. Our findings may improve estimates of age-specific risk and VE in similarly vaccinated populations and thus improve forecasting and vaccination strategies to combat seasonal influenza. ### Competing Interest Statement The authors report grants from National Institutes of Health during the conduct of the study. HQM receives research support from Seqirus unrelated to this work. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. ### Funding Statement Funding for this project was provided by the National Institutes of Health (NIH), Department of Health and Human Services, under grant DP2AI117921 (to SC), CEIRS Contract No. HHSN272201400005C (to SC), and NRSA Fellowship F32AI145177-01 (to PA). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. ### Author Declarations All relevant ethical guidelines have been followed and any necessary IRB and/or ethics committee approvals have been obtained. Yes All necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived. Yes Any clinical trials involved have been registered with an ICMJE-approved registry such as and the trial ID is included in the manuscript. Not Applicable I have followed all appropriate research reporting guidelines and uploaded the relevant Equator, ICMJE or other checklist(s) as supplementary files, if applicable. Yes Data for this study are available at <>
Cold Spring Harbor Laboratory Press
Appears in Collections:Artículos científicos

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