HIV affects more than 40 million people around the world, yet no HIV vaccine has yet emerged. Now, a drug that could prevent infection with the virus is being tested in Africa, Asia and the United States.
The trials of tenofovir, however, have already hit controversy. Two trials, one in Cambodia and one in Cameroon, were stopped in 2004 and 2005 because of government concerns about their methods. Several ethics issues emerged — for instance, how trial participants were chosen and how access to drugs would be assured after the trials.
In this article, Robert Grant of the Gladstone Institute of Virology and Immunology in San Francisco, United States, and colleagues explain why despite the difficulties in testing them, preventive drugs are a promising approach to tackling HIV/AIDS.
Tenofovir only needs to be taken once a day, and might even provide protection if some doses were missed. In addition, it does not seem to interact with tuberculosis drugs or with hormonal contraceptives, meaning it could be used in high-risk groups.
Grant and colleagues say that community advisors and local ethics review boards must be involved in designing the trial – even before seeking the sponsor's final approval. The daunting task of providing proven HIV preventive measures to poor countries must also be tackled, they say. But, they stress, a balance must be struck between conducting trials to very high standards and the need to stem the spread of HIV.