Results from a new study suggest COVID-19 was circulating in the U.S. weeks before the first cases were officially reported.
Scientists tested 24,000 blood samples collected in early 2020 for an unrelated study
Results from a new study suggest COVID-19 was circulating in the U.S. weeks before the first cases were officially reported.
Scientists tested 24,000 blood samples collected in early 2020 for an unrelated study