A single dose SARS-CoV-2 simulating particle vaccine induces potent neutralizing activities

Yin, Di; Ling, Sikai; Tian, Xiaolong; Li, Yang; Xu, Zhijue; Jiang, Hewei; Zhang, Xue; Wang, Xiaoyuan; Shi, Yi; Zhang, Yan; Da, Lintai; Tao, Sheng-ce; Wang, Quanjun; Xu, Jianjiang; Ying, Tianlei; Hong, Jiaxu; Cai, Yujia

Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) for which a vaccine is urgently needed to control its spreading. To facilitate the representation of a native-like immunogen without being infectious, here, we reported a SARS-CoV-2 vaccine candidate (designated ShaCoVacc) by incorporating spike-encoding mRNA inside and decorating spike protein on the surface of the virus simulating particles (VSPs) derived from lentiviral particles. We characterized the mRNA copy number, glycosylation status, transduction efficiency, and innate immune property of the new vaccine platform. Importantly, we showed the ShaCoVacc induced strong spike-specific humoral immune responses and potent neutralizing activities by a single injection. Additionally, we disclosed the epitopes of spike-specific antibodies using peptide microarray and revealed epitopes susceptible to specific neutralizing antibodies. These results support further development of ShaCoVacc as a candidate vaccine for COVID-19 and VSP may serve as a new vaccine platform for emerging infectious diseases.