Find the latest update on clinical trials for vaccines and drugs that might be able to treat COVID-19 caused by the coronavirus. This official site is from NIH (National Institutes of Health) National Library of Medicine. As of May 27, 2020, an amazing number of 1748 studies were listed, nearly four times the number (469) of six weeks ago. While more than 600 studies were not yet recruiting participants, more than 900 were recruiting or enrolling subjects by invitation. Given the pandemic was only declared March 11, this speed is quite impressive. Short summaries available for each study may give an idea of how long the study will continue. See what is still being studied for chloroquine and hydroxychloroquine; over 100 studies are still recruiting or enrolling subjects by invitation. A recent search for COVID vaccine showed 102 studies, up from 30 six weeks ago.