“ More than 30,000 participants at 100 clinical research sites in the United States are participating in the study, which launched on July 27, 2020, after resul

“ More than 30,000 participants at 100 clinical research sites in the United States are participating in the study, which launched on July 27, 2020, after results from earlier stage clinical testing indicated that the vaccine candidate is well-tolerated and immunogenic.” Source: https://www.nih.gov/news-events/news-releases/promising-interim-results-clinical-trial-nih-moderna-covid-19-vaccine https://www.nih.gov/news-events/news-releases/promising-inte...