Protection against rectal transmission of an emtricitabine-resistant simian/human immunodeficiency virus SHIV162p3 M184V mutant by intermittent prophylaxis with Truvada

Mian Er Cong, Ae S. Youngpairoj, Qi Zheng, Wutyi Aung, James Mitchell, Elizabeth Sweeney, Debra L. Hanson, R. Michael Hendry, Charles Dobard, Walid Heneine, J. Gerardo García-Lerma

Research output: Contribution to journalArticle


Daily preexposure prophylaxis (PrEP) with Truvada (emtricitabine [FTC] and tenofovir disoproxil fumarate [TDF]) is a novel HIV prevention strategy recently found to reduce HIV incidence among men who have sex with men. We used a macaque model of HIV transmission to investigate if Truvada maintains prophylactic efficacy against an FTC-resistant isolate containing the M184V mutation. Five macaques received a dose of Truvada 3 days before exposing them rectally to the simian/human immunodeficiency virus mutant SHIV162p3 M184V, followed by a second dose 2 h after exposure. Five untreated animals were used as controls. Virus exposures were done weekly for up to 14 weeks. Despite the high (>100-fold) level of FTC resistance conferred by M184V, all five treated animals were protected from infection, while the five untreated macaques were infected (P = 0.0008). Our results show that Truvada maintains high prophylactic efficacy against an FTC-resistant isolate. Increased susceptibility to tenofovir due to M184V and other factors, including residual antiviral activity by FTC and/or reduced virus fitness due to M184V, may all have contributed to the observed protection.

Original languageEnglish (US)
Pages (from-to)7933-7936
Number of pages4
JournalJournal of Virology
Issue number15
Publication statusPublished - Aug 2011
Externally publishedYes


ASJC Scopus subject areas

  • Immunology
  • Virology

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