The Second Affiliated Hospital of Chongqing Medical University has enrolled in the first batch of subjects for human testing of China's first recombinant subunit COVID-19 vaccine, which marked that the vaccine has officially entered the clinical trial stage. On June 23, according to the Second Affiliated Hospital of Chongqing Medical University, the vaccine, jointly developed by Chongqing Zhifei Biological Products Co., Ltd. and Institute of Microbiology, Chinese Academy of Sciences, was the second recombinant subunit COVID-19 vaccine which has entered clinical trials in the world.

In the COVID-19 vaccine test room, pic by Visual Chongqing.

Vaccines are the most effective means of preventing and controlling infectious diseases. At present, countries around the world are accelerating the research and development of COVID-19 vaccines. On January 29 this year, Zhifei Longcom Biopharmaceutical Co., Ltd, a wholly-owned subsidiary of Zhifei, signed the Framework Agreement of Cooperation Intention with the Institute of Microbiology, Chinese Academy of Sciences. The two sides pledged to develop the recombinant subunit COVID-19 vaccine jointly. The project has been included in the "public security risk prevention and control and emergency technical equipment" critical special project under the national emergency special-key research and development plan.

the first batch of subjects is on clinical test

Through joint efforts, researchers from both sides have developed the recombinant subunit COVID-19 vaccine by adopting the recombinant DNA technology to use the receptor-binding domain (RBD) of the spike glycoprotein of the novel coronavirus as antigen together with traditional adjuvant.

"The efforts we made in developing the recombinant subunit vaccine was to find the part of the novel coronavirus gene responsible for producing the spike glycoprotein, and then we used microbes as petri dishes to produce the spike protein we need to make vaccines," said Professor Ren Hong, President of the Second Affiliated Hospital of Chongqing Medical University. Currently, the vaccines for the novel coronavirus under development include inactivated vaccine, recombinant subunit vaccine, adenovirus vector vaccine, attenuated influenza virus vector live vaccine, nucleic acid vaccine, and so on.

The results of the preliminary animal challenge protection experiments with the recombinant subunit vaccine showed that the vaccine was able to induce high levels of neutralizing antibodies, significantly reduce the viral load of lung tissue, mitigate the lung injury caused by a viral infection, and has an obvious protective effect.