Chlamydia, Gonorrhea, Syphilis Prevention Now Includes Re-Purposed Products

While there are no U.S. FDA preventive vaccines and few chemoprophylaxis options targeting bacterial sexually transmitted infections (STIs), syphilis, chlamydia, and gonorrhea cases have increased in the United States.

In 2022, more than 2.5 million cases of syphilis, gonorrhea, and chlamydia were reported by the U.S. Centers for Disease Control and Prevention (CDC).

The most alarming concerns center around syphilis and congenital syphilis epidemics, signaling an urgent need for swift innovation and collaboration from all STI prevention partners, says the CDC.

On June 6, 2024, the CDC published its recommendation for the use of doxycycline postexposure prophylaxis (doxy PEP), a novel, ongoing, patient-managed biomedical STI prevention strategy for a selected population.

Doxycycline is a tetracycline antibiotic that generally treats infections by preventing the growth and spread of bacteria, such as acne and malaria.

The CDC now recommends that certain people who have had a bacterial STI diagnosed in the past 12 months should receive counseling that doxy PEP can be used as postexposure prophylaxis to prevent these infections.

Following shared decision-making with their healthcare provider, the CDC recommends that certain persons be offered a prescription for doxy PEP to be self-administered within 72 hours after having unprotected sex. The recommended dose of doxy PEP is 200 mg and should not exceed a maximum dose of 200 mg every 24 hours.

Furthermore, persons prescribed doxy PEP should undergo bacterial STI testing at anatomic exposure sites at baseline and every 3–6 months after that. Ongoing need for doxy PEP should be assessed every 3–6 months.

And HIV screening should be performed according to current CDC recommendations.

Seperately, in the United Kingdom, the Joint Committee on Vaccination and Immunisation recommended a targeted vaccination program in 2023 using the 4CMenB vaccine to prevent gonorrhea.

Various studies and real-world evidence suggest that the MenB vaccine provides cross-protection against gonorrhea. Two doses are estimated to reduce the chances of getting gonorrhea by 33%.

As of June 2024, the CDC has not issued a similar MenB vaccine recommendation.