1. Influenza A(H3N2) Antibody Responses to Standard-Dose Versus Enhanced Influenza Vaccine Immunogenicity in Older Adults and Prior Season's Vaccine Status.
- Author
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Zhong S, Ng TWY, Skowronski DM, Iuliano AD, Leung NHL, Perera RAPM, Ho F, Fang VJ, Tam YH, Ip DKM, Havers FG, Fry AM, Aziz-Baumgartner E, Barr IG, Peiris M, Thompson MG, and Cowling BJ
- Subjects
- Humans, Aged, Aged, 80 and over, Male, Female, Hong Kong epidemiology, Immunogenicity, Vaccine, Vaccination methods, Antibody Formation immunology, Squalene administration & dosage, Squalene immunology, Influenza Vaccines immunology, Influenza Vaccines administration & dosage, Influenza A Virus, H3N2 Subtype immunology, Antibodies, Viral blood, Influenza, Human prevention & control, Influenza, Human immunology, Hemagglutination Inhibition Tests
- Abstract
Background: Annual influenza vaccination is recommended for older adults but repeated vaccination with standard-dose influenza vaccine has been linked to reduced immunogenicity and effectiveness, especially against A(H3N2) viruses., Methods: Community-dwelling Hong Kong adults aged 65-82 years were randomly allocated to receive 2017-2018 standard-dose quadrivalent, MF59-adjuvanted trivalent, high-dose trivalent, and recombinant-HA quadrivalent vaccination. Antibody response to unchanged A(H3N2) vaccine antigen was compared among participants with and without self-reported prior year (2016-2017) standard-dose vaccination., Results: Mean fold rise (MFR) in antibody titers from day 0 to day 30 by hemagglutination inhibition and virus microneutralization assays were lower among 2017-2018 standard-dose and enhanced vaccine recipients with (range, 1.7-3.0) versus without (range, 4.3-14.3) prior 2016-2017 vaccination. MFR was significantly reduced by about one-half to four-fifths for previously vaccinated recipients of standard-dose and all 3 enhanced vaccines (β range, .21-.48). Among prior-year vaccinated older adults, enhanced vaccines induced higher 1.43 to 2.39-fold geometric mean titers and 1.28 to 1.74-fold MFR versus standard-dose vaccine by microneutralization assay., Conclusions: In the context of unchanged A(H3N2) vaccine strain, prior-year vaccination was associated with reduced antibody response among both standard-dose and enhanced influenza vaccine recipients. Enhanced vaccines improved antibody response among older adults with prior-year standard-dose vaccination., Competing Interests: Potential conflicts of interest. B. J. C. has consulted for AstraZeneca, Fosun Pharma, GSK, Haleon, Moderna, Novavax, Pfizer, Roche, and Sanofi Pasteur. All other authors report no potential conflicts. All authors have submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Conflicts that the editors consider relevant to the content of the manuscript have been disclosed., (© The Author(s) 2023. Published by Oxford University Press on behalf of Infectious Diseases Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)
- Published
- 2024
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