PROJECT SUMMARY / ABSTRACT This proposal is a renewal application for years 11-15 of a 5-year National Research Service Award Institutional Research Grant to support a training program in HIV Epidemiology and Prevention Sciences at the Johns Hopkins Bloomberg School of Public Health (BSPH) and the Johns Hopkins School of Medicine (SOM), entitled the “Johns Hopkins HIV Epidemiology and Prevention Sciences Training Program.” The program will be led by Shruti Mehta PhD, MPH who has been the deputy director of this program for the past 10 years. We are requesting support for 3 pre- and 4 post-doctoral trainees The program mission is to train pre-doctoral students and post-doctoral fellows to become leaders at the forefront of highest priority HIV research with advanced competencies and state-of-the-art skills in three training tracks: 1) HIV Epidemiology and Implementation Science Methods including training in (1) Populations and Study Designs, including identifying, recruiting, and retaining populations relevant for domestic and international HIV research as well as contemporary designs for implementation science; (2) Measurement issues in populations infected with and at risk for HIV, including innovative methods for surveillance, population-based measures of disease burden and mHealth/online strategies for data collection; (3) Inference techniques, including causal inference, mathematical modeling; and (4) Synthesis and Implementation of research findings to practice, including systematic reviews, cost-effectiveness analyses, and barriers to implementation of HIV programs; 2) HIV Clinical and Laboratory Sciences including training in (1) the epidemiology, prevention and management of major co- infections with HIV including hepatitis C virus (HCV) infection, tuberculosis and SARS-CoV-2/COVID-19; (2) epidemiology and pathogenesis of HIV and age-associated co-morbidities; and (3) Measurement and use (e.g., phylodynamics) of genetic, virologic and immunologic factors that can inform our knowledge of the pathogenesis and transmission of HIV; and 3) HIV Prevention Sciences including how to prevent and reduce the prevalence and incidence of HIV through training in (1) Design and Analysis of HIV biomedical, behavioral and integrated strategies for prevention trials, including treatment as prevention research (TasP), PrEP, HIV vaccine and passive immune-therapy trials, and (2) Community-based population-level approaches to HIV prevention and control. Our program, which is fully integrated through the JHU Center for AIDS Research (CFAR) has resulted in a rich and interactive environment for trainees working in HIV augmented by the exceptionally innovative, productive and collaborative HIV research conducted by epidemiological, clinical, prevention and implementation scientists throughout Johns Hopkins BSPH, and SOM.