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  • Oral presentation
  • Open Access

Clinical Trials of DNA and Recombinant Adenovector (rAd) Vaccines for HIV

Retrovirology20052(Suppl 1):S61

https://doi.org/10.1186/1742-4690-2-S1-S61

Published: 8 December 2005

Keywords

  • Peptide
  • Fusion Protein
  • Cell Response
  • Antibody Response
  • Cytokine Expression

Background

Gene-based vaccine delivery is an important strategy for induction of T cell responses that may be critical for a successful AIDS vaccine. Despite promising results in animal models, evidence of immune responses to DNA and rAd vaccines in humans has been limited.

Materials and methods

Three Phase I studies have evaluated a series of DNA and rAd vaccine candidates expressing constructs encoding clades A, B, and C Envelope and clade B Gag and Pol with or without Nef, as fusion proteins or individually.

Results

T cell and antibody responses are detected by IFN-α ELISpot and FACS detection of intracellular IL-2 or IFN-α in the large majority of vaccinees. Env peptide pools elicit the strongest response, but the 6-plasmid and rAd product also induced robust responses to Gag, Pol, and Nef. Both T cell and humoral responses were dose dependent. The T cell responses induced by DNA are detectable for at least 52 weeks, and the pattern of cytokine expression evolves over time with fewer IFN-γ and more IL-2 producing T cells at one year.

Conclusion

DNA and rAd5 vaccine candidates are well tolerated and induce broad, durable immune responses. The combination will be tested in Phase II trials beginning 4Q2005.

Notes

Authors’ Affiliations

(1)
Vaccine Research Center, NIAID, NIH, Bethesda, USA

Copyright

© The Author(s) 2005

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