Every year on the occasion of World AIDS Day, 1 December, the Joint UN Programme on HIV/AIDS (UNAIDS) releases a report on pressing issues facing the global response to the AIDS pandemic. As the AIDS and COVID-19 pandemics collide, the 2021 World AIDS Day report warns that the colossal new challenges created by COVID-19 threaten the gains made against AIDS thus far. There have been substantial setbacks, particularly during the first six months of the crisis. People living with HIV are also at elevated risk of COVID-19-related morbidity and mortality. In many places, the upheaval caused by COVID-19 has summoned the inventiveness and resilience that have become hallmarks of the HIV response. HIV programmes that are well-resourced, willing to adapt, and anchored in strong community involvement have tended to cope the best. The Global AIDS Strategy 2021-2026 and the UN General Assembly''s 2021 Political Declaration on Ending AIDS call on countries to address inequalities and close gaps. With no time to spare, those agreed actions are not being made at the required speed and scale. What is at stake is bigger than AIDS. During negotiations on a global framework for pandemic prevention, preparedness, and response, the hard-won successes and bitter failures from the response to AIDS have experiences to share. Those lessons must be quickly learned and applied to end AIDS within the next decade, to swiftly defeat COVID-19, and to proactively confront the pandemics of tomorrow