The second, they said, involves several vaccine developers working in one large trial -- an unprecedented method for vaccine development in the US. Members of ACTIV's clinical trials working group are expected to discuss the options on a call Wednesday. Moderna, based in Massachusetts, is working on a vaccine with the National Institute of Allergy and Infectious Diseases, a part of the NIH. The researchers then wait and see if there is a difference in Covid-19 infections rates between the vaccine group and the control group. Corey said the overall effort -- several vaccine companies working this fast -- is unprecedented.

Source: CNN May 13, 2020 16:07 UTC