Serological testing of blood donors in the United States to identify SARS-CoV-2-reactive antibodies: December 2019 to January 2020, in order to determine whether SARS-CoV was present in the serum before the first case was detected in the United States on January 19, 2020 -2 Reactive antibodies, the American Red Cross collected 7389 residual archived samples of routine blood donations from December 13, 2019 to January, 2020, from 9 states (California, Connecticut, Iowa) The anti-CDS-CoV-2 antibodies of residents of the states, Massachusetts, Michigan, Oregon, Rhode Island, Washington and Wisconsin were tested on the CDC. Through IgG and IgM ELISA, micro-neutralization test, Ortho total Ig S1 ELISA and receptor binding domain/Ace2 blocking activity test, for pan Ig enzyme-linked immunosorbent assay (ELISA) for whole ear The protein reacted with the specimen was tested. These findings indicate that SARS-CoV-2 may have been introduced to the United States before January 19, 2020.
https://academic.oup.com/cid/advance-article/doi/10.1093/cid/ciaa1785/6012472