An adenovirus-vectored COVID-19 vaccine confers protection from SARS-COV-2 challenge in rhesus macaques

Feng, Liqiang; Wang, Qian; Shan, Chao; Yang, Chenchen; Feng, Ying; Wu, Jia; Liu, Xiaolin; Zhou, Yiwu; Jiang, Rendi; Hu, Peiyu; Liu, Xinglong; Zhang, Fan; Li, Pingchao; Niu, Xuefeng; Liu, Yichu; Zheng, Xuehua; Luo, Jia; Sun, Jing; Gu, Yingying; Liu, Bo; Xu, Yongcun; Li, Chufang; Pan, Weiqi; Zhao, Jincun; Ke, Changwen; Chen, Xinwen; Xu, Tao; Zhong, Nanshan; Guan, Suhua; Yuan, Zhiming; Chen, Ling

The rapid spread of coronavirus SARS-CoV-2 greatly threatens global public health but no prophylactic vaccine is available. Here, we report the generation of a replication-incompetent recombinant serotype 5 adenovirus, Ad5-S-nb2, carrying a codon-optimized gene encoding Spike protein (S). In mice and rhesus macaques, intramuscular injection with Ad5-S-nb2 elicits systemic S-specific antibody and cell-mediated immune (CMI) responses. Intranasal inoculation elicits both systemic and pulmonary antibody responses but weaker CMI response. At 30 days after a single vaccination with Ad5-S-nb2 either intramuscularly or intranasally, macaques are protected against SARS-CoV-2 challenge. A subsequent challenge reveals that macaques vaccinated with a 10-fold lower vaccine dosage (1 × 10(10) viral particles) are also protected, demonstrating the effectiveness of Ad5-S-nb2 and the possibility of offering more vaccine dosages within a shorter timeframe. Thus, Ad5-S-nb2 is a promising candidate vaccine and warrants further clinical evaluation.