Towards a next-day antibiotic against sexually transmitted infections?

Today we’re talking about prevention of sexually transmitted diseases and an antibiotic that could provide double protection when in doubt.

Géraldine Zamansky, journalist at the Health Magazine on France 5, talks to us today about a question of sexual health with information concerning very good results from a French clinical trial on the prevention of sexually transmitted diseases.

franceinfo: You tell us Géraldine, that we are wrong to associate syphilis and gonorrhea, formerly called gonorrhea, with previous centuries?

Geraldine Zamansky: Yes, and this French clinical trial called ANRS Doxyvac, also concerns a third less known disease, but also caused by a bacteria: chlamydia. It is also against it and syphilis that the results have been excellent, with protection in more than 80% of cases.

The results were less good against gonorrhea, with only 33% effectiveness. Because these sexually transmitted infections really do not belong to the past. A network of general practitioners even saw the number of cases of syphilis and gonorrhea detected in their practices double between 2020 and 2022.

This mainly concerned men, having relationships with men. While heterosexual women were most affected by chlamydia, which can impair their fertility.

What is the solution that would therefore provide at least double protection?

It is an antibiotic, doxycycline, taken here on average within 15 hours after risky sexual intercourse, that is to say without a condom. The idea is that it arrives in the body very quickly to destroy the bacteria, before it can proliferate.

Its lower effectiveness against gonorrhea is not a surprise, as Professor Jean-Michel Molina, who coordinated this trial, promoted by the ANRS (emerging infectious diseases), explained to me. Because resistance of gonococci to this antibiotic is very common. The study therefore also tested the effectiveness on them of a vaccine against a fairly similar bacteria, meningococcus, but without success.

The idea would be a “morning after” antibiotic in some way?

Exactly. But Professor Molina told me that we had to be careful because of the risk of antibiotic resistance. And it would therefore be necessary to identify the population that could benefit the most. Always as part of overall sexual health care.

With regular screenings for HIV and these infections which remain without symptoms for a long time. Without forgetting to recall the protection provided by the condom, but without denying the difficulties which still hinder its use today. Particularly because of the taboos that persist on all these diseases.