A trial of a preventive HIV vaccine candidate has begun enrollment in the United States and South Africa. The Phase 1 trial will evaluate a novel vaccine known as VIR-1388 for its safety and ability to induce an HIV-specific immune response in people. The National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, has provided scientific and financial support throughout the lifecycle of this HIV vaccine concept and is contributing funding for this study.