Serologic Testing of US Blood Donations to Identify Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2)–Reactive Antibodies: December 2019–January 2020

Abstract

Background SARS-CoV-2, the virus that causes COVID-19 disease, was first identified in Wuhan, China in December 2019, with subsequent worldwide spread. The first U.S. cases were identified in January 2020. Methods To determine if SARS-CoV-2 reactive antibodies were present in sera prior to the first identified case in the U.S. on January 19, 2020, residual archived samples from 7,389 routine blood donations collected by the American Red Cross from December 13, 2019 to January 17, 2020, from donors resident in nine states (California, Connecticut, Iowa, Massachusetts, Michigan, Oregon, Rhode Island, Washington, and Wisconsin) were tested at CDC for anti-SARS-CoV-2 antibodies. Specimens reactive by pan-immunoglobulin (pan Ig) enzyme linked immunosorbent assay (ELISA) against the full spike protein were tested by IgG and IgM ELISAs, microneutralization test, Ortho total Ig S1 ELISA, and receptor binding domain / Ace2 blocking activity assay. Results Of the 7,389 samples, 106 were reactive by pan Ig. Of these 106 specimens, 90 were available for further testing. Eighty four of 90 had neutralizing activity, 1 had S1 binding activity, and 1 had receptor binding domain / Ace2 blocking activity >50%, suggesting the presence of anti-SARS-CoV-2-reactive antibodies. Donations with reactivity occurred in all nine states. Conclusions These findings suggest that SARS-CoV-2 may have been introduced into the United States prior to January 19, 2020.

Early Identification of SARS-CoV-2 Emergence in the DoD via Retrospective Analysis of 2019-2020 Upper Respiratory Illness Samples

“…Our results are similar to other retrospective testing that focused on PCR-based detection of residual samples [4-6]. Evaluation of residual specimens using antibody tests is still an on-going effort and may lead to different data as better assays comes available [7].…”

Immunogenicity and crossreactivity of antibodies to the nucleocapsid protein of SARS-CoV-2: utility and limitations in seroprevalence and immunity studies

“…In fact, increasing number of reports in the literature are consistent with some antibodies to HCoV being crossreactive with the betacoronaviruses SARS-CoV-2 and SARS-CoV-1. [28][29][30][31][32] Interestingly, significant protein similarity between SARS-CoV-1, SARS-CoV-2, and other HCoV has been reported for N, including a highly conserved motif in the N-terminal (NT) half of the protein (FYYLGTGP) 33 and relevant immunodominant epitope regions. 24,34 Likewise, preexisting SARS-CoV-2-specific T cells have also been reported in »40%À60% of unexposed individuals and attributed to crossreactivity with HCoV previously encountered.…”

Biorepositories (biobanks) of human body fluids and materials as archives for tracing early infections of COVID-19

“…While these may diminish its usefulness as an approach for detecting ongoing infections, for which the reliability needs to be improved by adopting smarter testing strategies ( CDC, 2020f ) or combining with other testing methods ( Guo et al., 2020 ), the method itself serves a useful tool for conducting retrospective investigations on early infections and propagation of COVID-19, especially in the lack of pre-archived samples specifically fulfilling such a purpose. In fact, the usefulness of this approach was demonstrated in two recent serological surveys published in the interim during the review of this article, which showed real-life evidence that antibody testing of archived human blood donations can be a useful tool for identifying early infections of COVID-19 in the population before the first known local case of COVID-19 infection ( Apolone et al., 2020 ; Basavarain et al., 2020 ). These findings confirmed the earlier observation of SARS-CoV-2 antibodies in a small number of stored plasma samples ( n = 5) in Lombardy, Italy and the postulation that a prior unnoticed circulation of the virus had occurred in the area ( Percivalle et al., 2020 ).…”