SARS-CoV-2 seroprevalence and neutralizing activity in donor and patient blood from the San Francisco Bay Area

Ng, Dianna L.; Goldgof, Gregory M.; Shy, Brian R.; Levine, Andrew G.; Balcerek, Joanna; Bapat, Sagar P.; Prostko, John; Rodgers, Mary; Coller, Kelly; Pearce, Sandy; Franz, Sergej; Du, Li; Stone, Mars; Pillai, Satish K.; Sotomayor-Gonzalez, Alicia; Servellita, Venice; Martin, Claudia Sanchez San; Granados, Andrea; Glasner, Dustin R.; Han, Lucy M.; Truong, Kent; Akagi, Naomi; Nguyen, David N.; Neumann, Neil M.; Qazi, Daniel; Hsu, Elaine; Gu, Wei; Santos, Yale A.; Custer, Brian; Green, Valerie; Williamson, Phillip; Hills, Nancy K.; Lu, Chuanyi M.; Whitman, Jeffrey D.; Stramer, Susan; Wang, Candace; Reyes, Kevin; Hakim, Jill M.C.; Sujishi, Kirk; Alazzeh, Fariba; Pham, Lori; Oon, Ching-Ying; Miller, Steve; Kurtz, Theodore; Hackett, John; Simmons, Graham; Busch, Michael P.; Chiu, Charles Y.

We report very low SARS-CoV-2 seroprevalence in two San Francisco Bay Area populations. Seropositivity was 0.26% in 387 hospitalized patients admitted for non-respiratory indications and 0.1% in 1,000 blood donors. We additionally describe the longitudinal dynamics of immunoglobulin-G, immunoglobulin-M, and in vitro neutralizing antibody titers in COVID-19 patients. Neutralizing antibodies rise in tandem with immunoglobulin levels following symptom onset, exhibiting median time to seroconversion within one day of each other, and there is >93% positive percent agreement between detection of immunoglobulin-G and neutralizing titers.