title: Antibody and Th1-type cell-mediated immune responses in elderly and young adults immunized with the standard or a high dose influenza vaccine.
abstract: A comparative analysis of antibody and cell-mediated immune responses was performed in ambulatory medically stable elderly and young adults who received the standard-dose of trivalent inactivated influenza vaccine, containing 15 μg of hemagglutinin (HA) per virus strain, or a high-dose vaccine containing 60 μg HA per virus strain. Among the elderly, the high dose vaccine induced greater HAI (hemagglutination inhibition) and virus neutralization antibody titers than the standard dose vaccine. These responses, however, did not achieve the magnitude of those induced by the standard dose vaccine in young adults. Vaccine-specific circulating T cells producing IFN-γ were detected in the elderly and young adults following immunization. However, there were no significant differences in the IFN-γ responses among groups. On the other hand, the standard dose vaccine in the elderly resulted in the highest proportion of complete non-responders who failed to elicit either an HAI or an IFN-γ response. This study provides further evidence that a higher dose vaccine for the elderly may result in enhanced immune responses which are predicted to improve protection although still of lower magnitude than those induced in younger healthier individuals.
authors.affiliation: Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, MD 21201, USA. wchen@medicine.umaryland.edu
authors.forename: Wilbur H
authors.initials: WH
authors.lastname: Chen
authors.forename: Alan S
authors.initials: AS
authors.lastname: Cross
authors.forename: Robert
authors.initials: R
authors.lastname: Edelman
authors.forename: Marcelo B
authors.initials: MB
authors.lastname: Sztein
authors.forename: William C
authors.initials: WC
authors.lastname: Blackwelder
authors.forename: Marcela F
authors.initials: MF
authors.lastname: Pasetti
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000914:Antibodies, Viral / Q000097:blood*; D000917:Antibody Formation; D004306:Dose-Response Relationship, Immunologic; D004311:Double-Blind Method; D005260:Female; D006385:Hemagglutination Inhibition Tests; D006801:Humans; D007111:Immunity, Cellular; D007070:Immunoglobulin A / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood; D053118:Influenza A Virus, H1N1 Subtype / Q000276:immunology; D053122:Influenza A Virus, H3N2 Subtype / Q000276:immunology; D007252:Influenza Vaccines / Q000008:administration & dosage*; D007251:Influenza, Human / Q000517:prevention & control*; D007371:Interferon-gamma / Q000276:immunology; D008297:Male; D018417:Th1 Cells / Q000276:immunology*; D015164:Vaccines, Inactivated; D055815:Young Adult
chemical_list: D000914:Antibodies, Viral; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007252:Influenza Vaccines; D015164:Vaccines, Inactivated; D007371:Interferon-gamma