Antiretroviral Pre-Exposure Prophylaxis Does Not Enhance Immune Responses to HIV in Exposed but Uninfected Persons.

Published: December 17, 2014

PubMed
Pattacini L1, Murnane PM2, Baeten JM3, Fluharty TR1, Thomas KK4, Bukusi E5, Katabira E6, Mugo N7, Donnell D8, Lingappa JR9, Celum C3, Marzinke M10, McElrath MJ11, Lund JM12; for the Partners PrEP Study Team.
Original Article:  1.usa.gov/1CdeFJT

Abstract

BACKGROUND:
Antiretroviral pre-exposure prophylaxis (PrEP), using daily oral combination tenofovir disoproxil fumarate plus emtricitabine, is an effective HIV prevention strategy for populations at high-risk of HIV acquisition. While the primary mode of action for the protective effect of PrEP is likely direct anti-viral activity, non-human primate studies suggest that PrEP may also allow for development of HIV-specific immune responses, hypothesized to result from aborted HIV infections providing a source of immunologic priming. We sought to evaluate whether PrEP affects the development of HIV-specific immune response in humans.

METHODS AND RESULTS:
Within a PrEP clinical trial among high-risk heterosexual African men and women, we detected HIV-specific CD4+ and CD8+ peripheral blood T-cell responses in 10-20% of 247 subjects evaluated. The response rate and magnitude of T-cell responses did not vary significantly between those assigned PrEP versus placebo, and no statistically significant difference between those assigned PrEP and placebo was observed in measures of innate immune function.

CONCLUSIONS:
We found no evidence to support the hypothesis that PrEP alters either the frequency or magnitude of HIV-specific immune responses in HESN. These results suggest that PrEP is unlikely to serve as an immunologic prime to aid protection by a putative HIV vaccine.

Full text of article available at link below:  1.usa.gov/1CdeFJT
 

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