Bacterial sexually transmitted infections (STIs), such as gonorrhea, chlamydia, and syphilis, are increasing across the United States. In June 2024, the CDC announced new recommendations for a novel approach to combat this rise by using doxycycline as post-exposure prophylaxis (PEP). You may be familiar with using PEP to prevent viral infections like HIV or pregnancy, but this represents a new public health strategy for bacterial infection prevention.