The COVID-19 Reseach Data Base is a is a public-private consortium organized by Datavant, which provides data and a platform to publish research to help combat the disease.  I am a member of their scientific steering committee and this web site https://datavant.com/news/leading-healthcare-companies-announce-covid-19-research-database/ will provide the information you need to familiarize yourself with the available data and the procedure for accessing it.