In an @AllofUsResearch study, #antibody testing of more than 24K stored blood samples given by participants in Jan.-Mar. 2020 provided evidence of #COVID19 infections in five states (IL, MA, MS, PA, & WI) earlier than those states’ first reported cases. (1/4) We found a total of 9 samples w/ antibodies against SARS-CoV-2, collected as early as Jan. 7 and 8, 2020. Since antibodies take a few weeks to be detected after infection, this adds to evidence that the virus was present in the U.S. in late Dec. 2019. (2/4)