title: Randomized, controlled trial of high-dose influenza vaccine among frail residents of long-term care facilities.
abstract: BACKGROUND
  Despite vaccination, residents of long-term-care facilities (LTCFs) remain at high risk of influenza-related morbidity and mortality. More-effective vaccine options for this population are needed.
  
  
  METHODS
  We conducted a single-blinded, randomized, controlled trial comparing high-dose (HD) to standard-dose (SD) inactivated influenza vaccine (IIV) in 205 frail, elderly residents of LTCFs during the 2011-2012 and 2012-2013 influenza seasons. Hemagglutination inhibition (HI) antibody titers were measured at baseline and 30 and 180 days following vaccination.
  
  
  RESULTS
  A total of 187 subjects (91%) completed the study. The mean age was 86.7 years. Geometric mean titers (GMTs) were significantly higher (P < .05) at day 30 for HD recipients, compared with SD recipients, for all comparisons except influenza A(H1N1) during 2012-2013 (the HD formulation was noninferior to the SD formulation for influenza A[H1N1] during 2012-2013). GMTs for HD and SD recipients during 2011-2012 were as follows: influenza A(H1N1), 78 (95% confidence interval [CI], 45-136) and 27 (95% CI, 17-44), respectively; influenza A(H3N2), 26 (95% CI, 17-40) and 10 (95% CI, 7-15), respectively; and influenza B, 26 (95% CI, 19-35) and 14 (95% CI, 11-18), respectively. During 2012-2013, GMTs for HD and SD recipients were as follows: influenza A(H1N1), 46 (95% CI, 33-63) and 50 (95% CI, 37-67); influenza A(H3N2), 23 (95% CI, 18-31) and 14 (95% CI, 11-18), respectively; and influenza B, 26 (95% CI, 21-32) and 17 (95% CI, 14-22), respectively. GMTs were significantly higher at day 180 for HD recipients, compared with SD recipients, for influenza A(H3N2) in both years (P < .001).
  
  
  CONCLUSIONS
  Among frail, elderly residents of LTCFs, HD influenza vaccine produced superior responses for all strains except influenza A(H1N1) in 2012-2013.
  
  
  BACKGROUND
  NCT01654224.
authors.affiliation: Division of Geriatric Medicine.
authors.forename: David A
authors.initials: DA
authors.lastname: Nace
authors.affiliation: Department of Family Medicine, University of Pittsburgh, Pennsylvania.
authors.forename: Chyongchiou Jeng
authors.initials: CJ
authors.lastname: Lin
authors.affiliation: Vaccine and Gene Therapy Institute of Florida, Port Saint Lucie.
authors.forename: Ted M
authors.initials: TM
authors.lastname: Ross
authors.affiliation: Division of Geriatric Medicine.
authors.forename: Stacey
authors.initials: S
authors.lastname: Saracco
authors.affiliation: Division of Geriatric Medicine.
authors.forename: Roberta M
authors.initials: RM
authors.lastname: Churilla
authors.affiliation: Department of Family Medicine, University of Pittsburgh, Pennsylvania.
authors.forename: Richard K
authors.initials: RK
authors.lastname: Zimmerman
mesh_terms: D000369:Aged, 80 and over; D000914:Antibodies, Viral / Q000097:blood; D005260:Female; D016330:Frail Elderly; D006385:Hemagglutination Inhibition Tests; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000276:immunology; D053122:Influenza A Virus, H3N2 Subtype / Q000276:immunology; D009981:Influenza B virus / Q000276:immunology; D007252:Influenza Vaccines / Q000008:administration & dosage* / Q000276:immunology*; D007251:Influenza, Human / Q000517:prevention & control*; D008134:Long-Term Care; D008297:Male; D016037:Single-Blind Method
chemical_list: D000914:Antibodies, Viral; D007252:Influenza Vaccines
keywords: high-dose influenza vaccine; inactivated influenza vaccine; long-term care