For the first time, scientists have now seen a case of an individual contracting the human immunodeficiency virus (HIV) while being compliant with taking pre-exposure prophylaxis (PrEP) daily. The patient was allegedly infected with a multidrug-resistant strain of HIV. In other words, the strain of HIV acquired by the person who was taking PrEP is resistant to many levels of HIV medications.
A 43-year-old man who has sex with men (MSM) who had been taking PrEP 24 months before his HIV test provided a positive result. The researchers gave him a blood spot test to determine whether or not he had stayed compliant to PrEP, which it was inferred that the patient was compliant. The test also concluded that the HIV medication-resistant strain that he was infected with was indeed from only one person and not because of mutation of another strain of HIV after transmission. The patient is now on Tivicay (dolutegravir), Prezcobix (darunavir/cobicistat), and Edurant (rilpivirine), and continues to have an undetectable viral load.
This new drug-resistant strain doesn't surprise me. PrEP is 92% effective in preventing HIV transmission, so it isn't 100%, but neither is using a condom. Unfortunately, the only thing that is 100% effective is abstinence, and it is farfetched to try to preach that message.
PrEP was approved by the Food and Drug Administration (FDA) on July 16, 2012. I would say four years of no HIV infections for those who are compliant with taking PrEP is a huge step for public health in eradicating the threat of HIV transmission.
PrEP is made up of two medications: tenofovir and emtricitabine. In the world right now if someone is infected with HIV they usually either have resistance to tenofovir or emtricitabine. But they usually almost never have resistance to both tenofovir and emtricitabine at the same time.