Volume 6 Supplement 3

AIDS Vaccine 2009

Open Access

P14-10. Comparable immunogenicity of VRC DNA and rAd5 HIV-1 vaccines delivered by intramuscular, subcutaneous and intradermal routes in healthy adults (VRC 011)

  • JE Ledgerwood1,
  • L Novik1,
  • ME Enama1,
  • IJ Gordon1,
  • LA Holman1,
  • MC Nason1,
  • RT Bailer1,
  • M Roederer1,
  • RA Koup1,
  • JR Mascola1,
  • GJ Nabel1 and
  • BS Graham1
Retrovirology20096(Suppl 3):P198

DOI: 10.1186/1742-4690-6-S3-P198

Published: 22 October 2009

Background

DNA and rAd5 vaccines delivered intramuscularly have been studied in many phase I/II trials. Here, the immunogenicity of the NIAID Vaccine Research Center (VRC) DNA and rAd5 HIV-1 vaccines were evaluated after injection by intramuscular (IM), subcutaneous (SC) and intradermal (ID) routes of administration.

Methods

60 subjects were randomized to one of two schedules. Group 1 received 3 DNA vaccine injections followed by a recombinant adenoviral vector (rAd5) vaccine booster; Group 2 received rAd5 prime followed by rAd5 booster. Within each Group subjects were equally randomized to prime injections by the IM, SC or ID routes of administration and all groups received a boost with rAd5 by IM injection. Half of the subjects in each group had pre-existing Ad5 neutralizing antibody.

Results

All routes induced T cell and humoral immune responses in Ad5 naïve and pre-immune subjects. >95% of subjects made an antibody response to Env. T cell responses to Env were seen in >80% and T cell responses to Gag were seen in >50% of all study subjects. Env T cell responses were of greater magnitude than responses to Gag. The frequency and magnitude of T cell responses were not diminished in Ad5 pre-immune subjects as compared to naïve subjects in either of the ID primed groups.

Conclusion

In this exploratory study, SC delivery of DNA or rAd5 as a prime does not induce a higher frequency or magnitude of T cell immunity than IM delivery. ID delivery may provide a dose sparing effect and also deserves additional evaluation as a means to overcome pre-existing vector immunity.

Authors’ Affiliations

(1)
Clinical Trials Core, Vaccine Research Center, NIAID, NIH

Copyright

© Ledgerwood et al; licensee BioMed Central Ltd. 2009

This article is published under license to BioMed Central Ltd.

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