Quick Answer
STI prevention layers like a pyramid: vaccination (HPV, hepatitis A/B) at the base, then mutual testing before unprotected contact, then consistent condom use, then PrEP for HIV, then DoxyPEP for bacterial STIs in high-risk groups. No single method covers everything, but the combination approaches 100% prevention.
- Vaccines: HPV (warts and cancers), hepatitis A and B, mpox (JYNNEOS). None for chlamydia/gonorrhea/syphilis/herpes/HIV yet.
- Condoms: 80-98% effective for HIV, chlamydia, gonorrhea, trich; less for herpes and HPV (skin coverage limits).
- PrEP: daily or on-demand medication preventing HIV >99% effectiveness.
- DoxyPEP: doxycycline 200mg within 72 hours after condomless sex — reduces chlamydia/syphilis ~65-70%.
Context Most Pages Skip
No single prevention method blocks everything, which is why public health recommends combining them. Condoms are excellent for fluid-borne infections but miss skin-to-skin ones.
Building your personal prevention plan
Map your activities: condoms + mutual testing for new partners, PrEP if HIV risk is a concern, HPV vaccine if unvaccinated, DoxyPEP if you are a man who has sex with men and have multiple partners.
Sources & Further Reading
- CDC — Sexually Transmitted Infections
- CDC STI Treatment Guidelines
- WHO — Sexually transmitted infections fact sheet
- MedlinePlus — Sexually Transmitted Diseases
Figures reflect CDC surveillance and WHO estimates; they are population statistics, not personal risk predictions.