Brief Report: Closing the Implementation Gap: Prioritizing Rapid Science for Global HIV Impact.

The global HIV response has achieved significant progress in recent years, with the rapid adoption of policies enabling millions to access antiretroviral treatment and expanding prevention strategies like preexposure prophylaxis. However, persistent challenges-including socioeconomic inequities, fluctuating donor funding, and systemic barriers to equitable health care-continue to hinder progress. Implementation science, which focuses on integrating evidence-based practices into routine health care, is critical to overcoming these challenges but often suffers from delays that limit its ability to address emerging needs. This commentary advocates for prioritizing "rapid science" within the HIV response to close these gaps. Rapid science, using approaches such as rapid-cycle evaluation, adaptive study designs, embedded research teams, and real-time program data, enables more agile and context-sensitive decision making. These methods can reduce the multi-year lag that typically accompanies traditional implementation research, streamline regulatory and ethical review processes, and allow programs to test, iterate, and course-correct in near real time. By adopting rapid science, the HIV response can become more adaptable, sustainable, and impactful in an increasingly complex global health landscape.