title: A prospective study of the factors shaping antibody responses to the AS03-adjuvanted influenza A/H1N1 vaccine in cancer outpatients.
abstract: OBJECTIVE
  To identify the determinants of antibody responses to adjuvanted influenza A/H1N1/09 vaccines in a cohort of cancer outpatients.
  
  
  METHODS
  Patients with cancer and controls were enrolled in a prospective single-center field study. Two doses of AS03-adjuvanted pandemic influenza vaccine were administered to patients and one dose was administered to controls. Antibody responses were measured using hemagglutination inhibition and confirmed by microneutralization. Geometric mean titers (GMTs) and seroprotection rates (defined as GMTs ≥40) were compared.
  
  
  RESULTS
  Immunizations were safe and well tolerated in 197 cancer patients (lymphoma, 57; glioma, 26; lung or head and neck, 37; gastrointestinal, 41; breast, 36) and 138 controls. Similar seroprotection rates (82.3% versus 87%) and GMTs (336.9 versus 329.9) were achieved after two doses of adjuvanted vaccine in cancer patients and one dose in controls. Univariate analyses identified older age, prior immunization against seasonal influenza, lymphoma, CD4 count, active chemotherapy, and rituximab and steroid treatments as being associated with weaker antibody responses. However, only age and chemotherapy plus rituximab remained independent determinants of vaccine responses in multivariate analyses.
  
  
  CONCLUSIONS
  Two doses of AS03-adjuvanted influenza vaccine elicited potent antibody responses in most cancer patients despite ongoing chemotherapy, with the exception of rituximab-induced B-cell depletion. Oncology patients treated in an outpatient setting benefit from preventive vaccination against influenza with adjuvanted vaccines.
authors.affiliation: Center of Oncology, Geneva University Hospitals, 4 Rue Gabrielle Perret-Gentil, 1211 Geneva 4, Switzerland.
authors.forename: Andreas F
authors.initials: AF
authors.lastname: Hottinger
authors.forename: Anne-Claude C
authors.initials: AC
authors.lastname: George
authors.forename: Michael
authors.initials: M
authors.lastname: Bel
authors.forename: Laurence
authors.initials: L
authors.lastname: Favet
authors.forename: Christophe
authors.initials: C
authors.lastname: Combescure
authors.forename: Sara
authors.initials: S
authors.lastname: Meier
authors.forename: Stéphane
authors.initials: S
authors.lastname: Grillet
authors.forename: Klara
authors.initials: K
authors.lastname: Posfay-Barbe
authors.forename: Laurent
authors.initials: L
authors.lastname: Kaiser
authors.forename: Claire-Anne
authors.initials: CA
authors.lastname: Siegrist
authors.forename: Pierre-Yves
authors.initials: PY
authors.lastname: Dietrich
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000906:Antibodies / Q000097:blood / Q000276:immunology*; D000917:Antibody Formation / Q000276:immunology*; D005260:Female; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000276:immunology; D007252:Influenza Vaccines / Q000008:administration & dosage* / Q000276:immunology*; D007251:Influenza, Human / Q000150:complications / Q000517:prevention & control*; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000150:complications; D010045:Outpatients; D011446:Prospective Studies; D012737:Sex Factors
chemical_list: D000906:Antibodies; D007252:Influenza Vaccines