Signal Transduction and Targeted Therapy (Dec 2021)

Long-term stability and protection efficacy of the RBD-targeting COVID-19 mRNA vaccine in nonhuman primates

  • Hui Zhao,
  • Tie-Cheng Wang,
  • Xiao-Feng Li,
  • Na-Na Zhang,
  • Liang Li,
  • Chao Zhou,
  • Yong-Qiang Deng,
  • Tian-Shu Cao,
  • Guan Yang,
  • Rui-Ting Li,
  • Yi-Jiao Huang,
  • Yuan-Guo Li,
  • Yi-Ming Zhang,
  • Fang-Xu Li,
  • Yu-Ren Zhou,
  • Yu-Hang Jiang,
  • Xi-Shan Lu,
  • Shi-Hui Sun,
  • Meng-Li Cheng,
  • Kai-Ping Gu,
  • Mei Zhang,
  • Qing-Qing Ma,
  • Xiao Yang,
  • Bo Ying,
  • Yu-Wei Gao,
  • Cheng-Feng Qin

DOI
https://doi.org/10.1038/s41392-021-00861-4
Journal volume & issue
Vol. 6, no. 1
pp. 1 – 9

Abstract

Read online

Abstract Messenger RNA (mRNA) vaccine technology has shown its power in preventing the ongoing COVID-19 pandemic. Two mRNA vaccines targeting the full-length S protein of SARS-CoV-2 have been authorized for emergency use. Recently, we have developed a lipid nanoparticle-encapsulated mRNA (mRNA-LNP) encoding the receptor-binding domain (RBD) of SARS-CoV-2 (termed ARCoV), which confers complete protection in mouse model. Herein, we further characterized the protection efficacy of ARCoV in nonhuman primates and the long-term stability under normal refrigerator temperature. Intramuscular immunization of two doses of ARCoV elicited robust neutralizing antibodies as well as cellular response against SARS-CoV-2 in cynomolgus macaques. More importantly, ARCoV vaccination in macaques significantly protected animals from acute lung lesions caused by SARS-CoV-2, and viral replication in lungs and secretion in nasal swabs were completely cleared in all animals immunized with low or high doses of ARCoV. No evidence of antibody-dependent enhancement of infection was observed throughout the study. Finally, extensive stability assays showed that ARCoV can be stored at 2–8 °C for at least 6 months without decrease of immunogenicity. All these promising results strongly support the ongoing clinical trial.