A small pilot study using a daily dose of the antibiotic doxycycline as pre-exposure prophylaxis (PrEP) against sexually transmitted infections (STIs) has found that a group of HIV-positive gay men taking doxycycline was more than 70% less likely to be infected with an STI than men given financial incentives to avoid STIs, a significant difference. There were 76% fewer cases of syphilis, although the small size of the study meant that this difference was not statistically significant. Read More
