A prevention strategy that public health agencies have promoted since 2023 has stopped working against gonorrhea in Southern California, according to a new observational study of more than 26,000 patients. Effectiveness fell from 42.3 percent in early 2023 to negative 15 percent by the end of the study period.
The strategy, known as doxyPEP, involves taking a dose of the antibiotic doxycycline within 72 hours of unprotected sex. It remains effective against two other common sexually transmitted infections. Across the full study period, protection measured 66.5 percent against chlamydia and 60.7 percent against syphilis, but 1.8 percent against gonorrhea.
