Clinical trials

This study will create and follow an online cohort of sexual and gender minorities in Brazil to better understand the use of HIV prevention and treatment strategies, particularly pre-exposure prophylaxis (PrEP) and antiretroviral treatment (ART). Participants will complete online questionnaires at the beginning of the study and every three months for one year to provide information about medication use and adherence, sexual behaviors, HIV prevention and testing, sexually transmitted infections, mental health, and experiences of discrimination in health services. Participants who are using PrEP or ART and agree to take part in the intervention will be randomly assigned to receive either a digital intervention or no digital intervention. The digital intervention will consist of weekly WhatsApp messages for six months, including reminders and information intended to support adherence to PrEP or ART. The main question of the study is whether weekly WhatsApp messages can improve adherence to PrEP or ART among sexual and gender minorities in Brazil. The study hypothesis is that participants who receive the digital intervention will have higher adherence to PrEP or ART than participants who do not receive the intervention.

Up to 650,000 people in Brazil are living with chronic hepatitis c virus (HCV) infection. Hepatitis C is a silent disease, and up to 20% of cases can progress to liver cirrhosis and its complications. Rapid tests for diagnosis of HCV infection and non-invasive methods for detecting liver cirrhosis are available in the Brazilian Public Health System. Additionally, safe and highly effective drugs (direct-acting antivirals, DAAs) have been delivered for free for hepatitis C treatment by the Brazilian Unified Health System (Sistema Único de Saúde, SUS) since 2015. Sustained virological response (SVR) rates with DAAs in studies conducted in Brazil and Latin America were higher than 90%. Despite the availability of rapid tests for early diagnosis and effective drugs, the HCV continuum of care remains deficient in Brazil. It is estimated that only 10% of individuals known to have hepatitis C achieve HCV cure (SVR). This is explained by multiple barriers from diagnosis to treatment access, such as low rates of population screening (HCVST are not available in Brazil) and few available slots in tertiary centers for hepatitis C treatment by specialists. International studies have described that SVR rates by simplified hepatitis C treatment performed by non-specialists in the Primary Care System were similar to those treated in tertiary centers by specialists (standard-of-care). However, the optimal strategy for managing hepatitis C within the Brazilian-SUS remains unclear.This project aims to evaluate the improve of the HCV continuum of care by a implementation of a test-and-treat strategy in the Primary Care System in Brazil. The project consists of two parallel studies (and a sub-study). The project consists of two parallel studies (and a sub-study). Study I is a population-based cross-sectional screening study using rapid tests to determine the prevalence of HCV infection in people attending a Basic Health Care Unit. The sub-study associated with Study I is a cross-sectional study to assess the usability of a self-test for the detection of HCV antibodies in oral fluid (participants included in Study I). Study II is a phase IV open-label randomized clinical trial to evaluate the non-inferiority of simplified and decentralized hepatitis C treatment ("Simplified-and-Decentralized (SD) HCV treatment"; experimental arm) compared to specialist reference treatment ("Standard-of-Care (SC) HCV treatment"; control arm) within the SUS.

This study aims to improve access to HIV prevention using pre-exposure prophylaxis (PrEP) among underserved populations in Rio de Janeiro, including gay and bisexual men, transgender women, and sex workers. Despite the proven effectiveness of PrEP, many people at higher risk of HIV face barriers to accessing and continuing this prevention method, especially those living in socially and economically vulnerable communities. The study will evaluate whether offering PrEP directly in community-based settings-such as non-governmental organizations, mobile health units, and through telehealth and digital tools-can increase its uptake and continued use. Participants who test negative for HIV will be offered daily oral PrEP, along with counseling and follow-up support. Those who test positive will be referred for appropriate treatment. The main hypothesis is that delivering PrEP in community settings, combined with supportive strategies like mobile health interventions, will be feasible, acceptable, and more effective in reaching and engaging vulnerable populations, ultimately helping to reduce new HIV infections.

The goal of this clinical trial is to learn if doxycycline post-exposure prophylaxis (doxy-PEP) can help prevent bacterial sexually transmitted infections (STIs) among sexual and gender minorities in Rio de Janeiro, Brazil, including men who have sex with men, transgender women, and travestis who are living with HIV or using HIV pre-exposure prophylaxis (PrEP). Bacterial STIs such as syphilis, gonorrhea, and chlamydia remain common in these populations, even with existing prevention strategies. This study aims to answer the following questions: whether doxy-PEP can reduce the number of new STIs, whether it is safe and well tolerated, whether participants use it as recommended, and whether its use may contribute to antibiotic resistance or changes in the body's natural bacteria. Doxy-PEP involves taking a dose of doxycycline, an antibiotic, shortly after sexual activity to reduce the risk of acquiring STIs. Participants will first receive information and counseling about doxy-PEP, including its possible benefits and risks, and will then choose whether or not to use this prevention strategy. Those who choose to use doxy-PEP will take doxycycline after sex as instructed and will be followed for up to 48 weeks, with clinic visits approximately every three months. During these visits, participants will be tested for STIs, monitored for side effects, and asked about medication use, sexual health, and overall well-being. Researchers will collect information on new STI diagnoses, safety, and how consistently participants use doxy-PEP. The study will also explore participants' experiences and perceptions of this strategy. The results of this study will help determine whether doxy-PEP is a practical and acceptable approach for STI prevention in Brazil and may inform future public health strategies.

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 participants get HIV while using long-acting lenacapavir? How safe is long-acting lenacapavir in real-world health services? How many participants continue using their chosen prevention method over time? What factors help or make it harder for participants to stay on prevention? Researchers will compare two HIV prevention options to understand how they work in routine care: Long-acting lenacapavir, given as an injection under the skin every 6 months, Daily oral pre-exposure prophylaxis (PrEP), taken as a pill containing tenofovir disoproxil fumarate and emtricitabine, Participants will choose the prevention option they prefer after receiving counseling. This is not a randomized study. Researchers will follow participants for up to 2 years. Participants will: Receive either an injection every 6 months or take a daily pill, Visit the clinic regularly for HIV testing and health checkups, Receive testing and treatment for sexually transmitted infections, Answer questions about their health, medication use, and experiences, Receive prevention counseling and condoms. This study will help health services understand how to offer long-acting HIV prevention in Brazil and how to better support people who want to prevent HIV infection.

Phase 4 study to evaluate the immunogenicity and Safety of the 17DD Yellow Fever vaccine in HIV infected individuals, compared to non-HIV-infected individuals. Main objective: To compare the proportion of seroconversion and the geometric mean of neutralizing antibodies 30 days and 365 days after vaccine. Secondary objectives: To evaluate whether the titles of neutralizing antibodies are associated with CD4 lymphocyte counts, CD8 lymphocyte counts, CD4 nadir, HIV viral load and use of antiretroviral therapy. To assess the yellow fever vaccine viremia at day 10 after vaccine.To compare the incidence of adverse events in HIV-infected and non-HIV-infected individuals.