Cross-reactive antibody response between SARS-CoV-2 and SARS-CoV infections

Lv, Huibin; Wu, Nicholas C.; Tsang, Owen Tak-Yin; Yuan, Meng; Perera, Ranawaka A. P. M.; Leung, Wai Shing; So, Ray T. Y.; Chan, Jacky Man Chun; Yip, Garrick K.; Chik, Thomas Shiu Hong; Wang, Yiquan; Choi, Chris Yau Chung; Lin, Yihan; Ng, Wilson W.; Zhao, Jincun; Poon, Leo L. M.; Peiris, J. S. Malik; Wilson, Ian A.; Mok, Chris K. P.

The World Health Organization has recently declared the ongoing outbreak of COVID-19, which is caused by a novel coronavirus SARS-CoV-2, as pandemic. There is currently a lack of knowledge in the antibody response elicited from SARS-CoV-2 infection. One major immunological question is concerning the antigenic differences between SARS-CoV-2 and SARS-CoV. We address this question by using plasma from patients infected by SARS-CoV-2 or SARS-CoV, and plasma obtained from infected or immunized mice. Our results show that while cross-reactivity in antibody binding to the spike protein is common, cross-neutralization of the live viruses is rare, indicating the presence of non-neutralizing antibody response to conserved epitopes in the spike. Whether these non-neutralizing antibody responses will lead to antibody-dependent disease enhancement needs to be addressed in the future. Overall, this study not only addresses a fundamental question regarding the antigenicity differences between SARS-CoV-2 and SARS-CoV, but also has important implications in vaccine