Dr Vicente Estrada, a Spanish infectious disease doctor, has dedicated his career to studying and fighting HIV. But when Madrid, where he lives and works, became a hotspot for COVID-19, Dr Estrada and his colleagues pivoted their work to help find a treatment for the disease that is taking a devastating toll on many countries around the world. “This pandemic has changed my job and my activities, and I’m moving to cover it,” he said. “All my time at this moment is devoted to this pandemic.”Through the leadership of the World Health Organization, Dr Estrada and hundreds of other doctors around the world are now working together to find an effective treatment for COVID-19 through WHO’s Solidarity Clinical Trial.