JV for AIDS vaccine

Merck & Co and Aventis are combining their two most promising AIDS vaccines candidates in a joint human test in the US that will begin later this year.

For reasons neither company understands, monkeys that were injected first with the Merck vaccine and then later with the Aventis medicine seemed to fight off AIDS better than monkeys given either vaccine separately or in reverse order.

'It's very clear that there's a certain order of these candidates that's preferred,' said John Shiver, who leads Merck's HIV vaccine program.

The HIV vaccine field has been rocked by disappointments, most notably the recent failure of VaxGen vaccine candidate. Aware that hopes have been raised and dashed numerous times, Dr. Shiver warned that the vaccine programs of Merck, Aventis and their newly combined effort are still in their early stages.

'It is not a sign of desperation that the companies have decided to test their two vaccine candidates together', Dr Shiver said. Both companies are continuing to develop vaccines independently of each other, with Merck testing its vaccine in 1,300 HIV-infected and uninfected volunteers in 70 clinical sites.