WHO regularly issues scientific briefs to explain topics in-depth for a scientific audience. The brief on COVID-19 transmission summarizes what is known about how the virus spreads between people, who can transmit the virus and when people pass the infection from one to another, and the implications for preventive measures to be adopted. It also outlines some key areas where more research is needed and how these results will help inform advice and guidance. This information is important for understanding how best to prevent infection and limit the spread of the virus between people.
WHO scientific briefs are living documents, meaning they are updated as more studies become available. COVID-19 is a new disease and we are learning more every day.