Weeks after Truvada (tenofovir and emtricitabine) received US approval for HIV prevention in adults at high risk of infection, it remains unclear whether government and private health insurers would pay for it. Regulatory approval of Truvada for pre-exposure prophylaxis (PrEP) followed years of speculation about whether it would curb new infections.

"Instead of just trying to distribute it in massive numbers, we need to understand how we'll deliver PrEP, and to whom we'll deliver PrEP, along with making a good case for whatever investment that will require," said Mitchell Warren, executive director of the AIDS Vaccine Advocacy Coalition.

Demonstration projects by the National Institutes of Health and the California HIV/AIDS Research Program will focus on possible implementation strategies for specific groups. Warren said he is looking forward to these trials and would like private insurers and Medicaid and Medicare to cover PrEP.

Michael Weinstein, president of AIDS Healthcare Foundation, pledged his organization would oppose Medicare or Medicaid coverage. "We believe this will lead to more infections," Weinstein said of Truvada's approval for PrEP. Government insurance coverage for it would be a "bad use of public funds," he said.

A Centers for Medicare and Medicaid Services (CMS) spokesperson could not comment on a possible PrEP coverage decision. However, Truvada prescribed as part of antiretroviral therapy for people with HIV has been on Medicare Part D formularies for several years, he noted.

Most private insurers pay for Truvada prescribed as treatment, said Susan Pisano, a spokesperson for America's Health Insurance Plans. AHIP members usually base coverage decisions on medical reviews, clinical trial reports, and decisions by federal agencies including CMS. But it is too early to say whether members will pay for PrEP, she said.