Instead of simply treating sexually transmitted infections with antibiotics, a new public-health movement seeks to use one such medication to prevent STIs in the first place. Promising research into variations on this method has raised hopes, but also concerns about whether this method might also contribute to another public health crisis: drug-resistant infections. 

One thing is clear: The nation is in dire need of game changers to battle the STI epidemic, as gonorrhea, chlamydia and syphilis have largely soared during the past decade.

Syphilis, which public health experts thought as recently as the 1990s could possibly be eliminated, has seen especially worrying increases among pregnant women in particular. Congenital syphilis — when…