This Notice of Special Interest (NOSI) highlights the need for research on strategies, and interventions to address vaccine hesitancy, uptake, and implementation among populations who experience health disparities in the US and its territories. Research is needed to understand and address misinformation, distrust, and hesitancy regarding uptake of vaccines (e.g., SARS-CoV-2, pneumococcal, influenza, hepatitis B, human papilloma virus (HPV)) among adults in the United States and territories, especially in populations at increased risk for morbidity and mortality due to long-standing systemic health and social inequities and chronic medical conditions. This NOSI is focused on adults 18 years and older except for SARS-CoV-2 and HPV-related vaccine topics, which may include eligible children and adolescents. The purpose of this NOSI is to solicit research to: 1) evaluate community-engaged interventions (e.g., expand reach, increase access, address psychosocial barriers) to facilitate vaccination uptake in clinical and community contexts; 2) evaluate organizational, local, state, and federal policies and initiatives that mitigate or exacerbate disparities in vaccine access, uptake, and series completion, and 3) understand and address barriers to increasing reach, access, and uptake of vaccinations among populations who experience health disparities.