Preexisting cross-reactivity to SARS-CoV-2 occurs in the absence of prior viral exposure. However, this has been difficult to quantify at the population level due to a lack of reliably defined seroreactivity thresholds. Using an orthogonal antibody testing approach, we estimated that about 0.6% of nontriaged adults from the greater Vancouver, Canada, area between May 17 and June 19, 2020, showed clear evidence of a prior SARS-CoV-2 infection, after adjusting for false-positive and false-negative test results. Using a highly sensitive multiplex assay and positive/negative thresholds established in infants in whom maternal antibodies have waned, we determined that more than 90% of uninfected adults showed antibody reactivity against the spike protein, receptor-binding domain (RBD), N-terminal domain (NTD), or the nucleocapsid (N) protein from SARS-CoV-2. This seroreactivity was evenly distributed across age and sex, correlated with circulating coronaviruses’ reactivity, and was partially outcompeted by soluble circulating coronaviruses’ spike. Using a custom SARS-CoV-2 peptide mapping array, we found that this antibody reactivity broadly mapped to spike and to conserved nonstructural viral proteins. We conclude that most adults display preexisting antibody cross-reactivity against SARS-CoV-2, which further supports investigation of how this may impact the clinical severity of COVID-19 or SARS-CoV-2 vaccine responses.
【저자키워드】 COVID-19, immunology, Adaptive immunity, 【초록키워드】 SARS-CoV-2, Antibody testing, SARS-COV-2 infection, peptide, Viral proteins, SARS-CoV-2 vaccine, Spike protein, Infant, cross-reactivity, Protein, Infants, Viral, Multiplex assay, Receptor-binding domain, nucleocapsid, RBD, NTD, threshold, Canada, false-negative, False-positive, N-terminal domain, Clinical severity, Evidence, evidence of, test results, maternal antibody, maternal antibodies, Support, antibody cross-reactivity, domain, population level, circulating, false, thresholds, antibody reactivity, uninfected, responses, approach, greater, defined, lack, conserved, absence, occur, the spike protein, correlated, reactivity, mapped, age and sex, waned, 【제목키워드】 SARS-CoV-2, uninfected, majority,