title: Immunogenicity and safety of intradermal trivalent influenza vaccination in nursing home older adults: a randomized controlled trial.
abstract: OBJECTIVE
  To compare the immunogenicity and safety between full-dose (15 μg) intramuscular (i.m.) and full-dose (15 μg) intradermal (i.d.) immunization of the trivalent influenza vaccine in nursing home older adults.
  
  
  METHODS
  A single-center, randomized, controlled, open-label, parallel group trial from October 2013 to April 2014.
  
  
  METHODS
  Nine nursing homes in Hong Kong.
  
  
  METHODS
  Hundred nursing home older adults (mean age: 82.9 ± 7.4 years).
  
  
  METHODS
  Fifty received i.d. (Intanza) and 50 received i.m. (Vaxigrip) vaccination.
  
  
  METHODS
  Baseline measurements included demographics, comorbidity, frailty and nutritional status. Day 21 and day 180 immunogenicity (seroconversion rate, seroprotection rate, geometric mean titer [GMT] fold increase in antibody titer) using hemagglutination-inhibition and adverse events were measured. Noninferiority and superiority of i.d. compared with i.m. vaccination in immunogenicity were analyzed. The study was registered on ClinicalTrials.gov; identifier: NCT 01967368.
  
  
  RESULTS
  At day 21, noninferiority in immunogenicity of the i.d. vaccination was demonstrated. The seroconversion rate of the H1N1 strain was significantly higher in the i.d. group. At day 180, immunogenicity of both groups fell but the GMT of all strains in i.d. group was higher and the difference was significant for H3N2 strain. The seroconversion rate and GMT fold increase of H3N2 strain was significantly higher in the i.d. group. Local adverse events was significantly more in i.d. group, but they were mild and resolved in 72 hours.
  
  
  CONCLUSIONS
  I.d. vaccination is noninferior, and even superior in some parts of immunogenicity assessment, to i.m. vaccination without compromising safety in nursing home older adults. I.d. vaccination is a good alternative to i.m. vaccination in this population.
authors: Department of Medicine and Geriatrics, TWGHs Fung Yiu King Hospital, Hong Kong SAR, China; Division of Geriatrics, Department of Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong SAR, China. Electronic address: tuenching@yahoo.com.hk.
authors: Tuen-Ching
authors: TC
authors: Chan
authors: Division of Infectious Disease, Department of Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong SAR, China.
authors: Ivan Fan-Ngai
authors: IF
authors: Hung
authors: Department of Microbiology, Queen Mary Hospital, The University of Hong Kong, Hong Kong SAR, China.
authors: Kwok-Hung
authors: KH
authors: Chan
authors: Department of Microbiology, Queen Mary Hospital, The University of Hong Kong, Hong Kong SAR, China.
authors: Clara Pui-Yan
authors: CP
authors: Li
authors: Department of Microbiology, Queen Mary Hospital, The University of Hong Kong, Hong Kong SAR, China.
authors: Patrick Tsz-Wai
authors: PT
authors: Li
authors: Department of Medicine and Geriatrics, TWGHs Fung Yiu King Hospital, Hong Kong SAR, China.
authors: James Ka-Hay
authors: JK
authors: Luk
authors: Division of Geriatrics, Department of Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong SAR, China.
authors: Leung-Wing
authors: LW
authors: Chu
authors: Department of Medicine and Geriatrics, TWGHs Fung Yiu King Hospital, Hong Kong SAR, China.
authors: Felix Hon-Wai
authors: FH
authors: Chan
mesh_terms: D000369:Aged, 80 and over; D005260:Female; D006723:Hong Kong; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype; D053122:Influenza A Virus, H3N2 Subtype; D007252:Influenza Vaccines / Q000008:administration & dosage* / Q000276:immunology*; D007251:Influenza, Human / Q000517:prevention & control* / Q000821:virology; D007271:Injections, Intradermal; D007273:Injections, Intramuscular; D008297:Male; D009735:Nursing Homes; D061214:Patient Safety
chemical_list: D007252:Influenza Vaccines
keywords: Influenza vaccination; immunogenicity; intradermal vaccination; nursing home older adults; randomized controlled trial; safety