Nearly three years ago on this blog (see “A Daily Pill Against HIV Infection”, Aug. 10, 2008) I reported that research was underway to determine whether HIV infection could prevented in healthy people by giving them AIDS drugs before they became infected, not after. It’s called pre-exposure prophylaxis (PrEP), and according to a news release from the CDC, there is now convincing evidence that it works!
In one study by researchers from the University of Washington in conjunction with the CDC, a daily pill comprised of two known AIDS drugs (or a placebo) was given to nearly 5,000 “discordant couples” in Kenya and Uganda (one partner HIV-infected, the other not). Uninfected partners who took the daily pill had a 73% lower chance of becoming infected, compared to those who received the placebo. The study was stopped early because the results were so clear-cut that it was deemed unethical to continue withholding the drug from the control group. A second study by the CDC of 1,200 sexually active young adults in Botswana revealed that those who took a daily PrEP pill had a 63% lower chance of infection, compared to those who did not.
Given these recent findings, PrEP is likely to become a new standard of prophylaxis for healthy, at-risk individuals who request it. However, it should be noted that the PrEP pill has not yet been tested in pregnant women, so it may not be for everyone.