A novel DNA and protein combination COVID-19 vaccine formulation provides full protection against SARS-CoV-2 in rhesus macaques

Li, Yuzhong; Bi, Yanwei; Xiao, Hongjian; Yao, Yueting; Liu, Xiaojuan; Hu, Zhengrong; Duan, Jinmei; Yang, Yaoyun; Li, Zhihua; Li, Yadong; Zhang, Heng; Ding, Chen; Yang, Jianbo; Li, Haiwei; He, Zhanlong; Liu, Longding; Hu, Guangnan; Liu, Shuying; Che, Yanchun; Wang, Shixia; Li, Qihan; Lu, Shan; Cun, Wei

The current study aims to develop a safe and highly immunogenic COVID-19 vaccine. The novel combination of a DNA vaccine encoding the full-length Spike (S) protein of SARS-CoV-2 and a recombinant S1 protein vaccine induced high level neutralizing antibody and T cell immune responses in both small and large animal models. More significantly, the co-delivery of DNA and protein components at the same time elicited full protection against intratracheal challenge of SARS-CoV-2 viruses in immunized rhesus macaques. As both DNA and protein vaccines have been proven safe in previous human studies, and DNA vaccines are capable of eliciting germinal center B cell development, which is critical for high-affinity memory B cell responses, the DNA and protein co-delivery vaccine approach has great potential to serve as a safe and effective approach to develop COVID-19 vaccines that provide long-term protection.