SARS-CoV-2 specific antibody responses in COVID-19 patients

NISREEN M.A. OKBA; Marcel A Muller; Wentao Li; Chunyan Wang; Corine H. GeurtsvanKessel; Victor M. Corman; Mart M. Lamers; Reina S. Sikkema; Erwin de Bruin; Felicity D. Chandler; Yazdan Yazdanpanah; Quentin Le Hingrat; Diane Descamps; Nadhira Houhou-Fidouh; Chantal B. E. M. Reusken; Berend-Jan Bosch; Christian Drosten; Marion P.G. Koopmans; Bart L. Haagmans

Validated serologic assays are crucial for patient contact tracing, identifying the viral reservoir hosts and for epidemiological studies. Epidemiological studies are urgently needed to help uncover the burden of disease, in particular, the rate of asymptomatic infections, and to get better estimates on morbidity and mortality. Additionally, these epidemiological studies can help reveal the extent of virus spread in households, communities and specific settings; which could help guide control measures Serological assays are also needed for evaluation of the results of vaccine trials and development of therapeutic antibodies. Among the four coronavirus structural proteins, the spike (S) and the nucleocapsid (N) are the main immunogens (5) . Here, we describe development of serological assays for the detection of virus neutralizing antibodies and antibodies to the nucleocapsid (N) protein and various spike (S) domains including the S1 subunit, and receptor binding domain (RBD) of SARS-CoV-2 in ELISA format. Using a wellcharacterized cohort of serum samples from PCR-confirmed SARS-CoV-2 and patients PCR-confirmed to be infected with seasonal coronaviruses and other respiratory pathogens, we validated and tested various antigens in different platforms developed in-house as well as a commercial platform.