Oswaldo Cruz Foundation

This study is testing how well a new, long-acting injection works to prevent HIV infection. Participants choose between getting an injection every six months or taking a daily pill, and researchers follow them for up to two years to see which option people prefer and stick with. …

This study is testing if taking a single dose of the antibiotic doxycycline after sex can prevent bacterial sexually transmitted infections (STIs) like syphilis, gonorrhea, and chlamydia. It involves 200 men who have sex with men, transgender women, and travestis in Rio de Janeir…