334. Is self administration of intradermal influenza vaccine a viable option for adults?
Session: Poster Abstract Session: Challenges in Vaccinology and Vaccine Exploration
Friday, October 21, 2011
Room: Poster Hall B1
  • McNeil Coleman IDSA 2011R.pdf (39.3 kB)
  • Background: Intradermally administered influenza vaccine is as immunogenic as intramuscular vaccine at a lower unit dose. New microinjection systems make it possible to self administer vaccine potentially reducing the cost and inconvenience. Objective: To compare the immunogenicity, reactogenicity, feasibility, and acceptability of self administered (SA) intradermal (ID) trivalent seasonal influenza vaccine (SIV) to health care professional (HCP) administered vaccine.

    Methods: Adults (18-60 years old), including HCP, were randomized to either SA or HCP administered (HCPA) ID SIV. Prior to vaccination subjects completed a questionnaire and had serology for haemagglutination inhibition (HAI) titres. Subjects in the NA group were vaccinated. The SA group were given an instruction sheet and administered their own vaccine with the nurse observing, but not assisting. All subjects completed a questionnaire and adverse event diaries for 7 days post vaccine. Serum for HAI was collected at day 21. Pre-post vaccine seroprotection, seroconversion, and geometric mean titre ratios (GMTR) were calculated.

    Results: 228 people were randomized with 227 vaccinated according to protocol: 114 SA and 113 HCPA. Groups did not differ by sex, age (median 34 years), SIV in past 4 years (92%), experience giving injections (31%), or levels of seroprotection at baseline. Nurses rated 111 of 114 (97%) SA as successful and 3 as failures. There was no difference for rates of seroconversion (23% vs. 27% to all 3 components, P=0.62, for SA and HCPA respectively) or GMTR (B/Brisbane/60/2008: 4.0, 4.3, P=0.74; A/Perth/16/2009: 10.4, 10.0, P=0.89; A/California/7/2009: 5.5, 8.0, P=0.06; for SA and HCPA respectively) for successfully vaccinated participants. SA subjects reported a lower mean pain rating (1.1 vs. 2.0; P<0.001) at vaccination, but had larger areas of redness (36.7 vs. 29.0 mm; P=0.02) post-vaccine. SA subjects were more likely than HCPA to prefer SA (41% vs. 17%; P<0.001, respectively) and 70% of all subjects preferred ID over intramuscular SIV.

    Conclusion: Self administration of ID-TIV using the microinjection system was immunologically non-inferior to HCPA. The ID vaccine was well received and SA preferred over HCPA by those who experienced SA during the trial.

    Subject Category: I. Adult and Pediatric Vaccines

    Shelly McNeil, MD1, Brenda Coleman, PhD2,3, Scott Halperin, MD1, Joanne Langley, MD1 and Allison McGeer, MD2,3, (1)Dalhousie University, Canadian Center for Vaccinology, IWK Health Centre, Halifax, NS, Canada, (2)Department of Microbiology, University of Toronto, Toronto, ON, Canada, (3)Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada


    S. McNeil, sanofi pasteur: Grant Investigator, Research support

    B. Coleman, None

    S. Halperin, Sanofi Pasteur: Grant Investigator and Research Contractor, Research grant

    J. Langley, None

    A. McGeer, sanofi pasteur: Grant Investigator, Research support

    Findings in the abstracts are embargoed until 12:01 a.m. EST Thursday, Oct. 20 with the exception of research findings presented at IDSA press conferences.