title: Pandemic influenza A/H1N1 vaccine administered sequentially or simultaneously with seasonal influenza vaccine to HIV-infected children and adolescents.
abstract: In order to evaluate the immunogenicity, safety and tolerability of the 2009 A/H1N1 MF59-adjuvanted influenza vaccine administered sequentially or simultaneously with seasonal virosomal-adjuvanted influenza vaccine to HIV-infected children and adolescents, 36 HIV-infected children and adolescents, and 36 age- and gender-matched healthy controls were randomised 1:1 to receive the pandemic vaccine upon enrollment and the seasonal vaccine one month later, or to receive the pandemic and seasonal vaccines simultaneously upon enrollment. Seroconversion and seroprotection rates against the pandemic influenza A/H1N1 virus were 100% two months after vaccine administration in both groups, regardless of the sequence of administration. Geometric mean titres against pandemic and seasonal antigens were significantly higher when the seasonal and pandemic vaccines were administered simultaneously than when the seasonal vaccine was administered alone. Local and systemic reactions were mild and not increased by simultaneous administration. In conclusion, the 2009 pandemic influenza A/H1N1 MF59-adjuvanted vaccine is as immunogenic, safe and well tolerated in HIV-infected children and adolescents as in healthy controls. Its simultaneous administration with virosomal-adjuvanted seasonal antigens seems to increase immune response to both pandemic and seasonal viruses with the same safety profile as that of the pandemic vaccine alone. However, because this finding cannot be clearly explained by an immunological viewpoint, further studies are needed to clarify the reasons of its occurrence.
authors.affiliation: Department of Maternal and Pediatric Sciences, Università degli Studi di Milano, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Via Commenda 9, 20122 Milan, Italy.
authors.forename: Susanna
authors.initials: S
authors.lastname: Esposito
authors.forename: Laura
authors.initials: L
authors.lastname: Tagliaferri
authors.forename: Cristina
authors.initials: C
authors.lastname: Daleno
authors.forename: Antonia
authors.initials: A
authors.lastname: Valzano
authors.forename: Irene
authors.initials: I
authors.lastname: Picciolli
authors.forename: Francesca
authors.initials: F
authors.lastname: Tel
authors.forename: Giulia
authors.initials: G
authors.lastname: Prunotto
authors.forename: Domenico
authors.initials: D
authors.lastname: Serra
authors.forename: Carlotta
authors.initials: C
authors.lastname: Galeone
authors.forename: Anna
authors.initials: A
authors.lastname: Plebani
authors.forename: Nicola
authors.initials: N
authors.lastname: Principi
mesh_terms: D000276:Adjuvants, Immunologic / Q000008:administration & dosage; D000293:Adolescent; D000914:Antibodies, Viral / Q000097:blood; D000917:Antibody Formation; D018791:CD4 Lymphocyte Count; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D002648:Child; D005260:Female; D006678:HIV / Q000502:physiology; D015658:HIV Infections / Q000276:immunology*; D006801:Humans; D007115:Immunization Schedule; D053118:Influenza A Virus, H1N1 Subtype / Q000276:immunology; D007252:Influenza Vaccines / Q000008:administration & dosage* / Q000009:adverse effects / Q000276:immunology; D007251:Influenza, Human / Q000517:prevention & control*; D008297:Male; D011136:Polysorbates / Q000008:administration & dosage; D013185:Squalene / Q000008:administration & dosage; D022721:Vaccines, Virosome / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology; D014779:Virus Replication
chemical_list: D000276:Adjuvants, Immunologic; D000914:Antibodies, Viral; D007252:Influenza Vaccines; C089950:MF59 oil emulsion; D011136:Polysorbates; D022721:Vaccines, Virosome; D013185:Squalene