On May 18, 2020, with $9 million from the COVID-19 Therapeutics Accelerator, an international group of physicians and scientists established a research network to evaluate promising therapies for COVID-19. The group, called the COVID-19 Research Outcomes Worldwide Network (CROWN) Collaborative, will test whether the antimalaria drug chloroquine can prevent COVID-19 infection or decrease its severity in front-line health-care workers. An estimated 30,000 such workers from across the globe will participate in the clinical trial, which the collaborative is calling the CROWN CORONATION trial.