Dr. McGowan said the size of the NIH grants reflects a change in Washington, D.C., where the Obama administration has shown greater interest in funding HIV-prevention research.

“The Bush administration had a very high level of discomfort embracing HIV prevention research in men,” he said. “But I think in the Obama administration that’s a non-issue. They regard domestic HIV prevention in men who have sex with men as an important research priority.”

It also reflects growing awareness that not only men have anal sex.

“There’s increasing evidence that men and women have anal sex, too,” he said. “If we are interested in HIV prevention, we have to look at options for both men and women.”