Poster abstracts

Poster number 85 submitted by Jack Evans

Cross-reactivity of COVID-19 patient serum neutralizing antibodies against emerging SARS-CoV-2 variants

John P. Evans (Molecular, Cellular, and Developmental Biology), Cong Zeng (Dept. Veterinary Biosciences, OSU), Panke Qu (Dept. Veterinary Biosciences, OSU), Yi-Min Zheng (Dept. Veterinary Biosciences, OSU), Shan-Lu Liu (Dept. Veterinary Biosciences, OSU)

Abstract:
SARS-CoV-2, the viral cause of COVID-19 disease, has recently mutated to produce several emerging “variants of concern” with reports of increased transmission and potential evasion of protective immunity. This is particularly concerning as large scale vaccination campaigns are well underway. Thus, it is critical to monitor the protective humoral immune response at both the individual and population levels, especially the efficacy of vaccines against emerging variants. To this end, we developed a sensitive luciferase-bearing, pseudotyped lentivirus-based virus neutralization assay to detect neutralizing antibody (nAb) titers in COVID-19 patient serum or plasma—nAb titers being the best measure of protection against viral infection. We first demonstrate the utility of this assay in detecting nAb titers in recovered COVID-19 patients and demonstrate a strong correlation between nAb titers and severity of disease. We further assess the relative resistance to neutralization of virus pseudotyped with SARS-CoV-2 Spike (S) from major emerging SARS-CoV-2 variants of concern. From this we identify variants which exhibit escape from the nAb response including the B.1.351 variant, first isolated in South Africa, and P1-501Y-V3 variant, first isolated in Brazil. We further identify the critical mutations leading to this nAb escape. Further monitoring of emerging SARS-CoV-2 variant sensitivity to nAbs from previously infected and vaccinated individuals will be critical to adapting public health and vaccination strategies as we seek to end the ongoing pandemic.

References:
Zeng, C., Evans, J.P., Pearson, R., Qu, P., Zheng, Y.M., Robinson, R.T., Hall-Stoodley, L., Yount, J., Pannu, S., Mallampalli, R.K. and Saif, L., 2020. Neutralizing antibody against SARS-CoV-2 spike in COVID-19 patients, health care workers, and convalescent plasma donors. JCI insight, 5(22).

Keywords: SARS-CoV-2, Neutralizing Antibody, Variants of Concern