We’re going to have to wait a little longer for our secret weapon against HIV. A major trial of one promising microbicide just found no protective effect against HIV. The microbicide, PRO 2000, had showed promise in a previous trial. This larger trial, however, found no impact.
PRO 2000 in two different strengths was tested against an inert gel. It was hoped that the PRO 2000 gel would block HIV’s entry into cells and therefore prevent infection. After one year of use, however, there was no difference in the infection risk between the inert gel and the PRO 2000 gels.
This wasn’t the only microbicide in development. An antiretroviral microbicide is currently under trial in South Africa. Antiretroviral microbicides use a different mechanism of action than PRO 2000 – they may well be more effective than PRO 2000. Let’s hope.