Background: People with HIV take drugs to keep the amount of virus in their body low. One type of these drugs, called integrase strand transfer inhibitors (INSTIs), can cause weight gain over time. Weight gain can cause diabetes, heart disease, and other serious issues. Researchers want to understand how INSTIs cause weight changes.

Summary: The goals of this clinical study are to compare the effectiveness, safety and tolerability of study drug, tenofovir alafenamide (TAF), versus placebo in teens and children with CHB and to learn more about the dosing levels in children.

Summary: The goal of this study is to learn how well long-acting lenacapavir works to prevent human immunodeficiency virus (HIV) infection in people at higher risk of getting HIV in Brazil. The study will also learn about safety, continued use over time, and whether people prefer this option compared to daily oral pre- exposure prophylaxis (PrEP). The main questions it aims to answer are: How many particip...