Unlike a condom, the operation is a one-time intervention, Ryan notes. And "now we have some very good data, so we can have an extremely strong impact." With fewer infected men, fewer women will also be at risk for HIV infection. But, as she points out, the impact is also proportional to the breadth and speed of the scale-up. If fewer men are circumcised or if the target year is met years later, the epidemic will continue spreading all that much more quickly. This momentum is also the reason for targeting sexually active men and adolescents rather than infants. Although protecting the next generation is a long-term goal, to curb the epidemic as quickly as possible—and lessen the likelihood that children born today will face as high a risk of contracting the illness when they are grown—the analyses suggest putting money toward the older boys and men.
"It doesn't obviate our need to think about other policies," Venkataramani says. But "from a harm-reduction standpoint," he notes, "it's as good as we've got right now."