"I don't take this action lightly," Pence said when he initially authorized the program. The move came following a recommendation by the CDC and state public-health officials, and since then, Pence has stressed that he still opposes needle exchanges as an "anti-drug" policy. But advocates see a conflicted governor, reluctantly acting in response to a crisis but unwilling to move aggressively enough to end it.

"I think he just wants this problem to go away, and it's not," said Beth Meyerson, co-director of the Rural Center for AIDS/STD Prevention at Indiana University's School of Public Health. Meyerson told me the needle-exchange program should be implemented statewide and that Pence acted to pre-empt legislation that would have authorized a broader policy. Indiana lawmakers late Wednesday night voted to approve a measure allowing other counties to seek approval for needle-exchange programs when infection rates hit epidemic levels. After initially resisting proposals to expand the policy, Pence said he would sign the legislation and that it would "save lives."

Pence, 55, took office in 2013 after serving a dozen years in the House. He had drawn some notice as a possible presidential contender in 2016. But that buzz diminished following the uproar earlier this year over his signing of the Religious Freedom Restoration Act, which prompted an outcry from gay-rights advocates and led to threats of a boycott of the state by businesses.

While HIV/AIDS prevention is more frequently discussed in the context of safe-sex practices, the virus's transmission among intravenous drug users has sparked a debate about needle-exchange programs since the onset of the epidemic in the early 1980s, said William McColl, director of health policy at AIDS United. The policy has always been a tough sell politically in the "Just Say No" culture toward drugs. Lawmakers couldn't stomach the thought of enabling the injection of heroin and other opiates, even as public-health experts insisted that providing addicts with clean syringes would reduce HIV/AIDS and hepatitis transmission. Congress first barred funding for needle exchanges in 1988, and while Democrats succeeded in lifting it during the early years of the Obama administration, the ban returned after Republicans re-took the House majority in 2010.

Despite the lack of federal funding, local needle-exchange programs were in place in nearly 200 locations across the U.S. in 2014, according to the Foundation for AIDS Research (amFAR). And experts say they work: Needle-exchange programs have been credited with a drop of more than 80 percent in incidences of HIV among intravenous drug users between 1988 and 2006, the CDC reported in 2008. "It both decreases incidence of HIV and decreases drug abuse," McColl said. The drop in drug use occurs because addicts who participate in needle exchanges are often taking their first steps toward protecting themselves and engaging with social services. By taking that initial precaution, McColl explained, "they're getting interested in their own health." At many sites, workers will offer drug users information about treating addiction, or refer them to other programs through which they can get help to reduce their dependence. The idea, he said, is "to meet the people where they are."