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Reduced Infectivity of Cold‐Adapted Influenza A H1N1 Viruses in the Elderly: Correlation with Serum and Local Antibodies
Author(s) -
Powers Douglas C.,
Murphy Brian R.,
Fries Louis F.,
Adler William H.,
Clements Mary Lou
Publication year - 1992
Publication title -
journal of the american geriatrics society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.992
H-Index - 232
eISSN - 1532-5415
pISSN - 0002-8614
DOI - 10.1111/j.1532-5415.1992.tb01938.x
Subject(s) - medicine , infectivity , antibody , virology , common cold , immunology , influenza a virus , correlation , h1n1 influenza , virus , covid-19 , disease , geometry , mathematics , infectious disease (medical specialty)
Objective To compare young and elderly adults in terms of their immune responses and rates of infection following intranasal vaccination with a live attenuated influenza virus. Design Time series, comparing outcomes in young and elderly convenience sample. Method Retrospective laboratory analysis of serum and nasal wash specimens collected during prior studies in which young or elderly volunteers had been inoculated with cold‐adapted influenza A/Kawasaki/86 (H1N1) reassortant virus. Setting Johns Hopkins Center for Immunization Research. Participants Healthy young and elderly adults with prevaccination serum hemagglutination inhibition (HAI) antibody titers ≤1:8. Outcome Measurements Antibody responses in serum and nasal washes. Main Results The proportion of vaccinees who developed any serum or local antibody response was higher in young compared with elderly subjects (20/20 vs 5/14, P < 0.0005). Resistance to infection with cold‐adapted virus correlated with pre‐vaccination levels of serum immunoglobulin G (IgG), serum IgA, and nasal wash IgA antibody to whole virus antigen. Age was highly correlated with a lack of response to vaccine by simple regression, but not when data were adjusted for pre‐existing antibody levels. Conclusions Cold‐adapted reassortant influenza A H1N1 viruses achieve lower rates of infection in elderly than young adults, primarily due to age‐related differences in preexisting levels of immunity which may not be reflected by HAI titer.