In 2020 and 2021, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a novel coronavirus, caused a global pandemic. Vaccines are expected to reduce the pressure of prevention and control, and have become the most effective strategy to solve the pandemic crisis. SARS-CoV-2 infects the host by binding to the cellular receptor angiotensin converting enzyme 2 (ACE2) via the receptor-binding domain (RBD) of the surface spike (S) glycoprotein. In this study, a candidate vaccine based on a RBD recombinant subunit was prepared by means of a novel glycoengineered yeast Pichia pastoris expression system with characteristics of glycosylation modification similar to those of mammalian cells. The candidate vaccine effectively stimulated mice to produce high-titer anti-RBD specific antibody. Furthermore, the specific antibody titer and virus-neutralizing antibody (NAb) titer induced by the vaccine were increased significantly by the combination of the double adjuvants Al(OH)₃ and CpG. Our results showed that the virus-NAb lasted for more than six months in mice. To summarize, we have obtained a SARS-CoV-2 vaccine based on the RBD of the S glycoprotein expressed in glycoengineered Pichia pastoris, which stimulates neutralizing and protective antibody responses. A technical route for fucose-free complex-type N-glycosylation modified recombinant subunit vaccine preparation has been established.

2020年和2021年，新型冠状病毒严重急性呼吸综合征冠状病毒2（SARS-CoV-2）引起了全球大流行。疫苗有望减轻防控压力，成为解决疫情危机的最有效策略。SARS-CoV-2 通过表面刺突 (S) 糖蛋白的受体结合域 (RBD) 与细胞受体血管紧张素转换酶 2 (ACE2) 结合来感染宿主。本研究利用新型糖工程酵母毕赤酵母制备了基于 RBD 重组亚基的候选疫苗。具有与哺乳动物细胞相似的糖基化修饰特征的表达系统。候选疫苗有效刺激小鼠产生高滴度抗RBD特异性抗体。_{此外，双佐剂Al(OH) 3}和CpG的组合显着提高了疫苗诱导的特异性抗体效价和病毒中和抗体(NAb)效价。我们的研究结果表明，病毒-NAb 在小鼠体内持续了六个多月。总而言之，我们已经获得了一种基于糖工程毕赤酵母中表达的 S 糖蛋白 RBD 的 SARS-CoV-2 疫苗，该疫苗可刺激中和和保护性抗体反应。无岩藻糖复合N型的技术路线-糖基化修饰的重组亚单位疫苗制剂已经建立。