Their efforts span the globe. Organizations including the American Red Cross and the U.S. Centers for Disease Control and Prevention are testing old blood specimens for the presence of antibodies to SARS-CoV-2, the virus that causes Covid-19. Blood banks in the U.S., Europe and other regions are discussing new approaches to testing blood samples for signs of infection.
The scientists want to see whether any of the samples, which were frozen and stored, contain SARS-CoV-2 antibodies, which could help reveal how long the virus was circulating in people before the first cases were discovered.
The report also called for the analysis of blood samples collected prior to the pandemic elsewhere in China and in other countries.