Our reporter Zhang Jiaxing
On March 1, the State Drug Administration approved the registration application of Zhifeilong Kema recombinant novel coronavirus protein vaccine (CHO cells) with conditions.
The vaccine is the first approved domestic recombinant new coronavirus protein vaccine.
The technical route of recombinant protein vaccine is one of the five new crown vaccine research and development technologies deployed in my country.
Its safety has been tried and tested.
The familiar hepatitis B vaccine that can be vaccinated for newborns is produced using this technical route.
Zheng Zhongwei, head of the vaccine research and development team of the Joint Prevention and Control Mechanism Scientific Research Team of the State Council, previously said, "The safety of recombinant protein vaccines has been verified for a long time, and other vaccines under this technical route have been tested for billions of people around the world. vaccinate."
Three shots of recombinant protein vaccine are effective against Omicron
Different from other well-known technical routes, the new crown recombinant protein vaccine adopts a three-needle immunization procedure. Phase III clinical trials conducted in adults aged 18-59 showed that after 2 doses of subjects were inoculated, the positive conversion rate of neutralizing antibodies was After 3 doses of subjects, the positive conversion rate of neutralizing antibodies reached 97%.
According to the data, the research results of the international multi-center phase III clinical trial of the vaccine show that after 3 doses of recombinant new coronavirus vaccine (CHO cells) for people aged 18 and over, they have protective efficacy against different new coronavirus variants.
According to the data released by Zhifei Bio’s public account, the protective efficacy of the vaccine against the alpha variant is 92.68%; the protective efficacy against the gamma variant is 100%; the protective efficacy against the kappa variant is 84.82%; the protective efficacy against the delta variant The protective efficacy of the strain was 81.38%.
The latest research shows that the vaccine can still provide good protection against the Omicron variant.
Genetically engineered antigens are produced in 'cell factories'
The working mechanism of recombinant protein vaccines is like using a part of the virus "artificial wax figure" to induce an immune response in the body.
The researchers designed the "wax skeleton" and placed it in cells or microorganisms. The new crown vaccine approved for marketing this time is expressed and produced by recombinant engineered cells CHO (the name of a domesticated cell factory), and synthesized according to the design antigen. The new coronavirus spike glycoprotein receptor binding domain protein is purified and added with aluminum hydroxide adjuvant to make a suspension vaccine injection, which is a vaccine that the public can vaccinate.
After vaccination, it can stimulate the body to produce immunity against the new coronavirus.
When interpreting the design strategy of the antigen "skeleton", Dai Lianpan, a researcher at the Institute of Microbiology, Chinese Academy of Sciences, said that the antigen of this new coronavirus vaccine is a structurally designed S protein receptor domain dimer antigen, which has a unique structure and does not carry any form The exogenous label can significantly improve the immunogenicity of the vaccine.
Recombinant protein vaccines can be produced more efficiently because they can be produced in "cell factories".
Yan Jinghua, the head of recombinant protein vaccine research and development and a researcher at the Institute of Microbiology of the Chinese Academy of Sciences, previously stated that the design of the dimer makes the antigen expression yield very high, and does not require a high-level biosafety laboratory production workshop, enabling large-scale industrial production.
Recombinant protein vaccines have been approved for sequential vaccination before they are marketed
At present, the vaccine has been approved for registration or emergency use in many places around the world.
According to the data, on March 1 last year, the vaccine was registered and marketed in Uzbekistan, becoming the first registered recombinant new coronavirus protein vaccine in the world. It was subsequently approved for emergency use in Indonesia, Colombia and other places.
Indonesia also approved it as a sequential booster shot for the inactivated Covid-19 vaccine.
In my country, the vaccine was approved for emergency use in China on March 10 last year. After nearly a year of real-world research and data and performance in epidemic prevention and control, it was awarded the qualification for "normalization" on March 1 this year. Approved for listing with conditions.
Before being approved for marketing, the vaccine was approved for sequential vaccination of two-shot inactivated vaccine recipients.
At the press conference of the Joint Prevention and Control Mechanism of the State Council on February 19, the relevant person in charge introduced, "Recently, with the approval of the Joint Prevention and Control Mechanism of the State Council, the National Health Commission has begun to deploy sequential strengthening immunizations."
This means that after the implementation of the sequential strengthening immunization strategy, people who have completed two doses of inactivated vaccines from Sinopharm Zhongsheng Beijing Company, Sinopharm Zhongsheng Wuhan Company, and Beijing Kexing Zhongwei Company can choose this recombinant developed by Zhifeilong Kema. Protein vaccines are given as booster shots.