An alarming rise in sexually transmitted infections like chlamydia, gonnorhea, and syphilis in the US calls for new prevention and treatment tactics. Dr. Matthew Hamill, a Johns Hopkins clinical researcher specializing in HIV and STIs, talks with Stephanie Desmon about DoxyPEP, or the use of antibiotic doxycycline after sexual contact. They discuss its effectiveness and availability, use in the context of antibiotic resistance, and why DoxyPEP isn't a silver bullet in the prevention of STIs.