SARS-CoV-2 seroprevalence and neutralizing activity in donor and patient blood.
Dianna L NgGregory M GoldgofBrian R ShyAndrew G LevineJoanna BalcerekSagar P BapatJohn ProstkoMary RodgersKelly CollerSandra PearceSergej FranzLi DuMars StoneSatish K PillaiAlicia Sotomayor-GonzalezVenice ServellitaClaudia Sanchez San MartinAndrea GranadosDustin R GlasnerLucy M HanKent TruongNaomi AkagiDavid N NguyenNeil Montgomery NeumannDaniel QaziElaine HsuWei GuYale A SantosBrian CusterValerie GreenPhillip WilliamsonNancy K HillsChuanyi M LuJeffrey D WhitmanSusan L StramerCandace WangKevin ReyesJill M C HakimKirk SujishiFariba AlazzehLori PhamEdward ThornborrowChing-Ying OonSteve MillerTheodore W KurtzGraham SimmonsJohn HackettMichael P BuschCharles Y ChiuPublished in: Nature communications (2020)
Given the limited availability of serological testing to date, the seroprevalence of SARS-CoV-2-specific antibodies in different populations has remained unclear. Here, we report very low SARS-CoV-2 seroprevalence in two San Francisco Bay Area populations. Seroreactivity was 0.26% in 387 hospitalized patients admitted for non-respiratory indications and 0.1% in 1,000 blood donors in early April 2020. We additionally describe the longitudinal dynamics of immunoglobulin-G (IgG), immunoglobulin-M (IgM), and in vitro neutralizing antibody titers in COVID-19 patients. The median time to seroconversion ranged from 10.3-11.0 days for these 3 assays. Neutralizing antibodies rose in tandem with immunoglobulin titers following symptom onset, and positive percent agreement between detection of IgG and neutralizing titers was >93%. These findings emphasize the importance of using highly accurate tests for surveillance studies in low-prevalence populations, and provide evidence that seroreactivity using SARS-CoV-2 anti-nucleocapsid protein IgG and anti-spike IgM assays are generally predictive of in vitro neutralizing capacity.