This initiative will solicit research to target gaps in knowledge about barriers and facilitators to ring use, interventions to improve uptake, adherence, and persistence on the vaginal ring, and implementation science studies to improve access to and distribution of the ring. Research topics may include, but are not limited to: studies of individual, interpersonal, and structural factors that are barriers and facilitators to uptake of, adherence to, and persistence on the vaginal ring when the ring is delivered in real world settings (i.e., outside of clinical or open label extension trials); development and testing of behavioral interventions to encourage uptake, consistent use of, and persistence on the vaginal ring; and implementation science studies to understand implementation barriers and facilitators to delivery of the vaginal ring, and to optimize delivery of the ring.