The COVID-19 pandemic caused significant disruption to medical education globally. Fogarty International Center (FIC) training programs, designed to strengthen research capacity in low- and middle-income countries (LMICs), through partnerships between United States and LMIC institutions were particularly vulnerable to COVID-19 disruptions. We adapted short-term training for our FIC HIV Patient-Centered Outcomes Research program in Tanzania to the virtual environment using synchronous, asynchronous, and blended approaches and a variety of teaching pedagogies. We evaluated the acceptability and effectiveness of the new trainings among trainees and facilitators using a mixed-methods approach. Ninety percent of trainees and Muhimbili University of Health and Allied Sciences (MUHAS) facilitators agreed that the virtual training methods used were effective. Trainees reported high levels of satisfaction with the technology, group work, and relevance to their research. More than 50% of trainees and MUHAS facilitators agreed that learning in the virtual environment was as effective as, or more effective than, traditional in-person learning. However, they desired more interaction, opportunities to ask U.S. facilitators questions, and choices about topics for online versus in-person trainings. Two-thirds of U.S. facilitators agreed that the virtual delivery method was an effective way for participants to learn the material, although they also rated interaction less favorably. Virtual training incorporating pedagogical best practices of blended learning and traditional teaching online was a feasible, acceptable, and effective way of conducting research training to junior scientists during COVID-19. Virtual learning could become an integral part of post-pandemic training with some adaptation to improve interactions.