title: Cross-subtype immunity against avian influenza in persons recently vaccinated for influenza.
abstract: Avian influenza virus (H5N1) can be transmitted to humans, resulting in a severe or fatal disease. The aim of this study was to evaluate the immune cross-reactivity between human and avian influenza (H5N1) strains in healthy donors vaccinated for seasonal influenza A (H1N1)/(H3N2). A small frequency of CD4 T cells specific for subtype H5N1 was detected in several persons at baseline, and seasonal vaccine administration enhanced the frequency of such reactive CD4 T cells. We also observed that seasonal vaccination is able to raise neutralizing immunity against influenza (H5N1) in a large number of donors. No correlation between influenza-specific CD4 T cells and humoral responses was observed. N1 may possibly be a target for both cellular and humoral cross-type immunity, but additional experiments are needed to clarify this point. These findings highlight the possibility of boosting cross-type cellular and humoral immunity against highly pathogenic avian influenza A virus subtype H5N1 by seasonal influenza vaccination.
authors.affiliation: Laboratory of Virology, National Institute for Infectious Diseases Lazzaro Spallanzani, Istituti di Ricovero e Cura a Carattere Scientifico, Via Portuense 292, Rome, Italy.
authors.forename: Cristiana
authors.initials: C
authors.lastname: Gioia
authors.forename: Concetta
authors.initials: C
authors.lastname: Castilletti
authors.forename: Massimo
authors.initials: M
authors.lastname: Tempestilli
authors.forename: Paola
authors.initials: P
authors.lastname: Piacentini
authors.forename: Licia
authors.initials: L
authors.lastname: Bordi
authors.forename: Roberta
authors.initials: R
authors.lastname: Chiappini
authors.forename: Chiara
authors.initials: C
authors.lastname: Agrati
authors.forename: Salvatore
authors.initials: S
authors.lastname: Squarcione
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Ippolito
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Puro
authors.forename: Maria R
authors.initials: MR
authors.lastname: Capobianchi
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Poccia
mesh_terms: D000328:Adult; D000917:Antibody Formation / Q000276:immunology*; D003429:Cross Reactions / Q000276:immunology*; D004334:Drug Administration Schedule; D005260:Female; D006282:Health Personnel; D006388:Hemagglutinins / Q000145:classification / Q000276:immunology; D006801:Humans; D007111:Immunity, Cellular / Q000276:immunology; D053118:Influenza A Virus, H1N1 Subtype / Q000276:immunology; D053122:Influenza A Virus, H3N2 Subtype / Q000276:immunology; D053124:Influenza A Virus, H5N1 Subtype / Q000276:immunology*; D007252:Influenza Vaccines / Q000145:classification* / Q000276:immunology*; D008297:Male; D008875:Middle Aged
chemical_list: D006388:Hemagglutinins; D007252:Influenza Vaccines