Article
Author: Zhang, Qiu ; Yang, Guohuan ; Hu, Chunxia ; Xu, Fangjingwei ; Zhao, Ronghua ; Xu, Jiang ; Fan, Huifen ; Lin, Kang ; Wang, Xuewei ; Liu, Lianxiao ; Li, Xinguo ; Yu, Zhibin ; Hou, Fujun ; Li, Yuwei ; Pan, Xinping ; Lu, Changrui ; Liu, Xiaoke ; Cai, Rujie ; Zhang, Yuntao ; Huang, Hongwei ; Jia, William ; Li, Jing ; Cheng, Xinhua ; Hua, Xianwu ; Wang, Hui ; Liu, Xiaohu ; Ding, Jun ; Lu, Jia ; Liu, Fei ; Cheng, Hang ; Yang, Xiaoming ; Wang, Zejun ; Jia, Rui
The coronavirus SARS-CoV-2 has mutated quickly and caused significant global damage. This study characterizes two mRNA vaccines ZSVG-02 (Delta) and ZSVG-02-O (Omicron BA.1), and associating heterologous prime-boost strategy following the prime of a most widely administrated inactivated whole-virus vaccine (BBIBP-CorV). The ZSVG-02-O induces neutralizing antibodies that effectively cross-react with Omicron subvariants. In naïve animals, ZSVG-02 or ZSVG-02-O induce humoral responses skewed to the vaccine's targeting strains, but cellular immune responses cross-react to all variants of concern (VOCs) tested. Following heterologous prime-boost regimes, animals present comparable neutralizing antibody levels and superior protection against Delta and Omicron BA.1variants. Single-boost only generated ancestral and omicron dual-responsive antibodies, probably by "recall" and "reshape" the prime immunity. New Omicron-specific antibody populations, however, appeared only following the second boost with ZSVG-02-O. Overall, our results support a heterologous boost with ZSVG-02-O, providing the best protection against current VOCs in inactivated virus vaccine-primed populations.