Development, clinical translation, and utility of a COVID-19 antibody test with qualitative and quantitative readouts

Bortz, Robert H.; Florez, Catalina; Laudermilch, Ethan; Wirchnianski, Ariel S.; Lasso, Gorka; Malonis, Ryan J.; Georgiev, George I.; Vergnolle, Olivia; Herrera, Natalia G.; Morano, Nicholas C.; Campbell, Sean T.; Orner, Erika P.; Mengotto, Amanda; Dieterle, M. Eugenia; Fels, J. Maximilian; Haslwanter, Denise; Jangra, Rohit K.; Celikgil, Alev; Kimmel, Duncan; Lee, James H.; Mariano, Margarette; Antonio, Nakouzi; Jose, Quiroz; Rivera, Johanna; Szymczak, Wendy A.; Tong, Karen; Barnhill, Jason; Forsell, Mattias N. E.; Ahlm, Clas; Stein, Daniel T.; Pirofski, Liise-anne; Goldstein, D. Yitzchak; Garforth, Scott J.; Almo, Steven C.; Daily, Johanna P.; Prystowsky, Michael B.; Faix, James D.; Fox, Amy S.; Weiss, Louis M.; Lai, Jonathan R.; Chandran, Kartik

The COVID-19 global pandemic caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) continues to place an immense burden on societies and healthcare systems. A key component of COVID-19 control efforts is serologic testing to determine the community prevalence of SARS-CoV-2 exposure and quantify individual immune responses to prior infection or vaccination. Here, we describe a laboratory-developed antibody test that uses readily available research-grade reagents to detect SARS-CoV-2 exposure in patient blood samples with high sensitivity and specificity. We further show that this test affords the estimation of viral spike-specific IgG titers from a single sample measurement, thereby providing a simple and scalable method to measure the strength of an individual’s immune response. The accuracy, adaptability, and cost-effectiveness of this test makes it an excellent option for clinical deployment in the ongoing COVID-19 pandemic.