In an April 24 Gay City News editorial (gaycitynews.com), Gay Men’s Health Crisis co-founder and writer Lawrence D. Mass, MD, writes that medications to help prevent the sexual transmission of HIV—called pre-exposure prophylaxis, or PrEP—“[show] enough promise now that [they] can be said to be the next frontier of harm reduction for HIV/AIDS.”

According to Dr. Mass, needle-exchange programs have greatly reduced HIV transmission, but there remains a need for effective reduction of sexual transmission of the virus.

“With needle exchanges, you’re not telling people they must change their habits,” Mass writes. “It’s the same concept with PrEP. People are not told they must change their sexual habits…the only guaranteed difference in conduct is that participants in this approach take prescribed medication before and during periods of sexual activity.”

Mass says there are many questions surrounding PrEP, such as whether or not otherwise healthy people will take HIV medications consistently for long periods of time, how to address potential side effects and debates about whether PrEP encourages unsafe sex. However, he says that with recent AIDS vaccine failures, a harm-reduction initiative for sexual transmission of HIV “remains our principal and only defense.”