A way to prevent HIV infection?
It has been almost 3 decades since the first reports of a mysterious ailment among the homosexual community of San Francisco. During the intervening time, millions of people have died worldwide, and many more remain infected. However we have come a tremendous distance with our understanding of virology, but have made little progress towards identifying a vaccine for HIV infection. A story in the New York Times describes a recent approach to try and prevent infection using another approach.
The drug Truvada is a combination of nucleoside analogs that inhibit the retroviral enzyme reverse transcriptase. Recent clinical studies appear to show that a daily dose of Truvada is able to prevent infection by HIV. With this promising preliminary study, a more complete pilot study is being funded by the National Institutes of Health. In this expanded study, 500 uninfected men will be recruited to test preexposure prophylaxis, or PrEP treatment. Particularly at risk groups, including young homosexual men and African Americans, will be monitored for compliance with taking Truvada, their sexual behavior, and their health status.
The study raises several questions for clinical studies in general, most significantly as to whether it is fair to provide expensive medications to HIV-negative individuals, when many more lack access to adequate medication? This is a question that we as a society must be able to answer, and in light of the lack of an inexpensive post-infection treatment option, preventing infection in the first place for a potentially long-term, chronic disease might be more cost effective in the long run. I see merits to both arguments; on the one hand, it is essential that we explore a very promising approach to preventing infection in the first place. The preliminary evidence suggests that Truvada prophylaxis is very effective in preventing HIV infection in couples where one partner is HIV positive and the other is not, with an up to 70% decrease in infection rates in an East African study. However, an editorial in the medical journal The Lancet opined “How can these drugs be provided as prevention to those high-risk populations, while people with the disease in need of treatment continue to go without?”
I personally feel that our present approach, with education towards the prevention of infection by safe-sex practices done a very good job lowering the infection rate in the US, and that access to medicines for those already infected should be a higher priority. Low cost medications do not exist currently, but the ones that we do have effectively turned a terminal diagnosis into a chronic, but fairly long-term survivable disease.