Pre-Exposure Prophylaxis or PrEP

Pre-exposure prophylaxis (PrEP) involves putting HIV negative people on antiretroviral drugs (ARV) with the aim of protecting them from HIV infection. This blog looks at some of the pros and cons of PrEP.

Saturday, July 20, 2013

Treatment Action Group Raises Concerns About Thai PrEP Trial

The media reacted predictably when it was announced that a pre-exposure prophylaxis trial in Thailand showed some promise in reducing HIV transmission among intravenous drug users (IDU). However, many raised concerns throughout the course of the trial about how it was being conducted. One concern was that clean needles were not provided to trial participants, even though these are known to be the best means of reducing transmission among IDUs. But there were other serious issues that put a question mark over the value of the trial.

Another observation is that "the extent to which tenofovir protected against parenteral versus sexual exposure is unknown". The extent to which sexual versus parenteral exposure may have been involved was never questioned in many other PrEP trials, in mass male circumcision trials and in trials of numerous other HIV prevention interventions. Many HIV related trials fail to account adequately for modes of transmission, assuming that the virus is almost always transmitted sexually, often despite evidence to the contrary.

I'm just curious to know why these concerns have been raised by the Treatment Action Group about this trial in particular, when serious concerns about some other HIV prevention trials don't seem to be heard much, at least, not without attracting accusations of 'denialism' and similar ad hominem responses.