A vaccine targeting the RBD of the S protein of SARS-CoV-2 induces protective immunity.

Yang, Jingyun; Wang, Wei; Chen, Zimin; Lu, Shuaiyao; Yang, Fanli; Bi, Zhenfei; Bao, Linlin; Mo, Fei; Li, Xue; Huang, Yong; Hong, Weiqi; Yang, Yun; Zhao, Yuan; Ye, Fei; Lin, Sheng; Deng, Wei; Chen, Hua; Lei, Hong; Zhang, Ziqi; Luo, Min; Gao, Hong; Zheng, Yue; Gong, Yanqiu; Jiang, Xiaohua; Xu, Yanfeng; Lv, Qi; Li, Dan; Wang, Manni; Li, Fengdi; Wang, Shunyi; Wang, Guanpeng; Yu, Pin; Qu, Yajin; Yang, Li; Deng, Hongxin; Tong, Aiping; Li, Jiong; Wang, Zhenling; Yang, Jinliang; Shen, Guobo; Zhao, Zhiwei; Li, Yuhua; Luo, Jingwen; Liu, Hongqi; Yu, Wenhai; Yang, Mengli; Xu, Jingwen; Wang, Junbin; Li, Haiyan; Wang, Haixuan; Kuang, Dexuan; Lin, Panpan; Hu, Zhengtao; Guo, Wei; Cheng, Wei; He, Yanlin; Song, Xiangrong; Chen, Chong; Xue, Zhihong; Yao, Shaohua; Chen, Lu; Ma, Xuelei; Chen, Siyuan; Gou, Maling; Huang, Weijin; Wang, Youchun; Fan, Changfa; Tian, Zhixin; Shi, Ming; Wang, Fu-Sheng; Dai, Lunzhi; Wu, Min; Li, Gen; Wang, Guangyu; Peng, Yong; Qian, Zhiyong; Huang, Canhua; Lau, Johnson Yiu-Nam; Yang, Zhenglin; Wei, Yuquan; Cen, Xiaobo; Peng, Xiaozhong; Qin, Chuan; Zhang, Kang; Lu, Guangwen; Wei, Xiawei

The novel Coronavirus SARS-CoV-2 causes a respiratory illness called COVID-19 leading to a pandemic. An effective preventive vaccine against this virus is urgently needed. As the most critical step during infection, SARS-CoV-2 uses its Spike protein receptor-binding domain (S-RBD) to engage with the host cell receptor angiotensin-converting enzyme 2 (ACE2)1,2. Here we showed that a recombinant vaccine comprising residues 319-545 of the S-RBD could induce a potent functional antibody response in the immunized mice, rabbits and non-human primates (Macaca mulatta) as early as 7 or 14 days after a single dose injection. The sera from the immunized animals blocked RBD binding to ACE2 expressed on the cell surface and neutralized the infection by SARS-CoV-2 pseudovirus and live SARS-CoV-2 in vitro. Importantly, the vaccination also provided protection in non-human primates from SARS-CoV-2 challenge in vivo. The elevated RBD-specific antibodies were also found in the sera from patients with COVID-19. Several immune pathways and CD4 T lymphocytes were implicated in the induction of the vaccine antibody response. Our finding highlights the importance of the RBD domain in the SARS-CoV-2 vaccine design and provides the rationale for the development of a protective vaccine through the induction of antibody against the RBD domain.