First case of someone on PrEP getting HIV

For the first time since PrEP emerged onto the scene, and gay men could protect themselves from a virus that exterminated nearly an entire generation of our gay predecessors, a man who was taking Truvada on a daily basis has contracted a drug resistant strain of HIV.

The case was presented on Thursday at the Conference on Retroviruses and Opportunistic Infections (CROI) in Boston.

A 43-year-old man from Toronto contracted the virus after 24 months of being on the drug, without any previous issues. His blood tests and pharmacy records show that the man was taking the drug as directed by his doctor around the time that he contracted the virus.

Truvada, generally, is extremely effective in preventing HIV in those who take it every day. But the scientists concluded that there is an important, though very rare exception: someone who is exposed to a virus strain that is resistant to both drugs included in Truvada, tenofovir and emtricitabine.

The Toronto man had sex with someone who carried a virus that was resistant to both of the drugs in Truvada, as well as others. Where the problem lies, is that we prevent the virus the same way we treat it, Richard Harrigan, director of research labs at the British Columbia Centre for Excellence in HIV and one of the study researchers, told BuzzFeed News.

“I think the evidence that we have says that in general PrEP is working quite well. But there are always exceptions, and we have to keep that in mind,” he said. “In the ideal world, there wouldn’t be any crossover between the drugs we use, but at this point we just don’t have that many things that have been shown to work.”

Exposure to a strain that is resistant to even one of the drugs in Truvada might decrease the effectiveness of the pills.