title: A new MF59-adjuvanted influenza vaccine enhances the immune response in the elderly with chronic diseases: results from an immunogenicity meta-analysis.
abstract: BACKGROUND
  The elderly are at a higher risk of morbidity and mortality associated with influenza infection than younger adults, but get less protection from conventional vaccination.
  
  
  OBJECTIVE
  We conducted a meta-analysis of all available data from clinical trials in the elderly on a recently introduced MF59-adjuvanted influenza vaccine to determine its immunogenicity and safety in subjects with underlying chronic disease who are at highest risk of influenza infection.
  
  
  METHODS
  Data on immunogenicity and safety from 3600 subjects immunized with either the MF59-adjuvanted or conventional comparator influenza vaccine in 13 clinical trials were analyzed by disease history. Geometric mean haemagglutination inhibition titres (GMTs) and differences between the vaccine groups were compared using two-way analysis of variance. Differences between vaccine groups in the percentages with post-immunization reactions were assessed using chi-squared test and Fischer's exact test.
  
  
  RESULTS
  At 28 days the adjuvanted:comparator GMT ratio for the A/H3N2 antigen was 1.18 in healthy elderly subjects and 1.43 in elderly subjects with chronic disease (p = 0.004). The respective GMT ratios were 1.17 versus 1.37 for the B antigen (p = 0.065) and 1.10 versus 1.17 for the A/H1N1 antigen (p = 0.41). Although post-immunization reactions were more common in the group receiving the adjuvanted vaccine, these were predominantly mild and transient, and none were serious.
  
  
  CONCLUSIONS
  The MF59-adjuvanted influenza vaccine is more immunogenic in elderly subjects than conventional non-adjuvanted influenza vaccines and especially so in those with chronic disease. Therefore, since its safety profile is clinically acceptable, this adjuvanted vaccine represents an excellent option for influenza immunization of elderly subjects at highest risk of complications.
authors.affiliation: Clinical Research and Medical Affairs, Chiron Vaccines, Marburg, Germany.
authors.forename: Angelika
authors.initials: A
authors.lastname: Banzhoff
authors.forename: Pantaleo
authors.initials: P
authors.lastname: Nacci
authors.forename: Audino
authors.initials: A
authors.lastname: Podda
mesh_terms: D000276:Adjuvants, Immunologic / Q000627:therapeutic use; D000368:Aged; D000369:Aged, 80 and over; D002908:Chronic Disease / Q000188:drug therapy*; D017322:Clinical Trials, Phase II as Topic; D017326:Clinical Trials, Phase III as Topic; D005260:Female; D006385:Hemagglutination Inhibition Tests; D006801:Humans; D007109:Immunity / Q000187:drug effects*; D007252:Influenza Vaccines / Q000276:immunology* / Q000627:therapeutic use; D008297:Male; D011136:Polysorbates / Q000627:therapeutic use; D011446:Prospective Studies; D016032:Randomized Controlled Trials as Topic; D016037:Single-Blind Method; D013185:Squalene / Q000276:immunology* / Q000627:therapeutic use; D016896:Treatment Outcome
chemical_list: D000276:Adjuvants, Immunologic; D007252:Influenza Vaccines; C089950:MF59 oil emulsion; D011136:Polysorbates; D013185:Squalene