title: Humoral and cellular immune responses to split-virion H5N1 influenza vaccine in young and elderly adults.
abstract: We evaluated the humoral and cellular immunogenicity of adjuvanted and non-adjuvanted H5N1 influenza vaccine in two groups of 300 adults: aged 18-60 and >60 years in a randomized, open-label, uncontrolled phase 2 trial. Participants received two injections (D0, D21) of 7.5 microg hemagglutinin without adjuvant or 30 microg with aluminum hydroxide adjuvant. Antibody responses and cytokine secretion were assessed before and after vaccination. Excluding the 6/300 non-elderly and 47/300 elderly participants with pre-existing antibodies, geometric mean titers (dil(-1)) on D42 were higher with 30 microg+Ad and were comparable between age groups. Participants with pre-existing antibodies responded strongly to the first vaccination (GMTs in the range 147-228 on D21). Vaccination increased both Th1 and Th2 T-cell responses. The predominantly Th1 profile observed before vaccination was unaffected by vaccination. H5N1 influenza vaccine is no less immunogenic in elderly adults than in younger adults and, due to a higher proportion non-naïve elderly, immunogenicity was higher in this latter group.
authors.affiliation: Center for Vaccinology, Ghent University and Hospital, De Pintelaan 185, 9000 Ghent, Belgium. Isabel.LerouxRoels@UGent.be
authors.forename: Isabel
authors.initials: I
authors.lastname: Leroux-Roels
authors.forename: Marie
authors.initials: M
authors.lastname: Van der Wielen
authors.forename: Froukje
authors.initials: F
authors.lastname: Kafeja
authors.forename: Corinne
authors.initials: C
authors.lastname: Vandermeulen
authors.forename: Rajeka
authors.initials: R
authors.lastname: Lazarus
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Snape
authors.forename: Tessa
authors.initials: T
authors.lastname: John
authors.forename: Christophe
authors.initials: C
authors.lastname: Carre
authors.forename: Nolwenn
authors.initials: N
authors.lastname: Nougarede
authors.forename: Stephanie
authors.initials: S
authors.lastname: Pepin
authors.forename: Geert
authors.initials: G
authors.lastname: Leroux-Roels
authors.forename: Karel
authors.initials: K
authors.lastname: Hoppenbrouwers
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Pollard
authors.forename: Pierre
authors.initials: P
authors.lastname: Van Damme
mesh_terms: D000276:Adjuvants, Immunologic; D000328:Adult; D000368:Aged; D000536:Aluminum Hydroxide / Q000276:immunology; D000914:Antibodies, Viral / Q000097:blood; D016207:Cytokines / Q000276:immunology; D005260:Female; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000276:immunology; D006801:Humans; D007111:Immunity, Cellular; D056724:Immunity, Humoral; D007117:Immunization, Secondary; D053124:Influenza A Virus, H5N1 Subtype / Q000276:immunology*; D007252:Influenza Vaccines / Q000276:immunology*; D007251:Influenza, Human / Q000276:immunology / Q000517:prevention & control*; D008297:Male; D008875:Middle Aged; D018417:Th1 Cells / Q000276:immunology; D018418:Th2 Cells / Q000276:immunology; D055815:Young Adult
chemical_list: D000276:Adjuvants, Immunologic; D000914:Antibodies, Viral; D016207:Cytokines; D019267:Hemagglutinin Glycoproteins, Influenza Virus; D007252:Influenza Vaccines; D000536:Aluminum Hydroxide