The Munich 25th International AIDS Conference
AIDS 2024 saw the term, “DoxyPrEP” (doxycycline pre-exposure prophylaxis to describe taking the antibiotic before sex), make its debut to join the better-known “DoxyPEP” (doxycycline post-exposure prophylaxis).
So, daily doxycycline versus only as needed, which is the current recommendation.
Researchers from opposite sides of the world presented findings on daily. A trial from Canada involving men who have sex with men, living with HIV and with a history of syphilis, showed reductions of 79% in syphilis, 92% in chlamydia and 68% in gonorrhoea in the doxycycline arm compared with the placebo arm. A study from Japan among female sex workers showed a drop in STI incidence from 232.3 to 79.2 per 100 person-years. Syphilis incidence was reduced to zero; there was a marginally significant reduction in chlamydia and no significant change in gonorrhoea.
STI rates among young women using PrEP in central, eastern, southern and western Africa are high. Past research shows that DoxyPEP effectively prevents STIs among cisgender men and trans women but not cisgender women because use of DoxyPEP is low, with barriers such as side effects, pill burden, stigma and fear of partner reaction. A study on DoxyPEP adherence among young women in Kenya concluded that adherence could be better supported by decreasing frequency and urgency of dosing to allow for optimal location and timing of dosing.
A big question mark hangs over the potential for antimicrobial resistance (AMR) with the prolonged use of doxycycline. Large-scale and continued surveillance is crucial to gain further evidence around AMR.