Five Covid-19 vaccines have been approved for use in China, and their safety and effectiveness are supported by certain data.

Five Covid-19 vaccines have been approved for use in China
Security and effectiveness are supported by certain data.

According to the data released by National Health Commission, as of April 3rd, 136.677 million doses of Covid-19 vaccine have been reported in various places.

At present, five Covid-19 vaccines have been approved for use in China. What’s the difference between these five vaccines? Which variety is better? The reporter interviewed relevant experts.

According to the technical route, the five vaccines are divided into three categories: one is inactivated vaccine, including three inactivated vaccines produced by Sinopharm Zhongsheng Beijing Company, Sinopharm Zhongsheng Wuhan Company and Beijing Kexing Zhongwei Company; The second is adenovirus vector vaccine, which is type 5 adenovirus vector vaccine produced by Tianjin Kangxinuo Company; The third is recombinant protein vaccine, which is recombinant novel coronavirus vaccine (CHO cells).

What is the difference between the three technical routes?

"Inactivated vaccine is a vaccine prepared by a series of purification techniques after the live virus is killed by physical and chemical methods." Wang Junzhi, deputy head of the expert group of the vaccine research and development special class of the State Council Joint Prevention and Control Mechanism and academician of China Academy of Engineering, said that its main feature is that the composition of the vaccine is similar to that of the natural virus, and its immune response is strong, so it has good safety. The vaccine is relatively stable, can be stored at 2-8 degrees Celsius for two to three years, and is convenient to transport; Take two injections of immunization.

"Adenovirus vector vaccine is a live vector vaccine made by taking adenovirus type 5 as a vector, introducing Covid-19 antigen gene and making it through bioreactor." Wang Junzhi said that the vaccine preparation process is relatively simple, and the research and development costs and production costs are relatively low, because it was successfully developed on the basis of the original platform of Ebola vaccine for adenovirus type 5 in our country. Vaccine can induce antibody production and enhance cellular immunity; You can take a single needle immunization.

"Recombinant protein vaccine is to express the most effective antigen components in vitro by genetic engineering. In vitro cells are cells commonly used by engineering cell lines in biological products, similar to industrial fermentation, and finally made into vaccines. " Yan Jinghua, a researcher at the Institute of Microbiology, Chinese Academy of Sciences, said that the whole production process is a process of protein expression and purification, and there is no live virus involved, so the production process is safe and easy for mass production. From the past use process of recombinant protein vaccine and the previous experimental results, the safety of recombinant protein vaccine can be guaranteed, and the adverse reaction rate is relatively low. The vaccine is refrigerated at 2-8 degrees Celsius, which has low requirements for transportation and storage conditions; Take two or three injections of immunization.

Which vaccine is more effective?

Wang Junzhi said that the three routes of Covid-19 vaccine have their own characteristics. No matter what technical route is adopted, the most important thing is to develop a safe, effective and quality-controlled vaccine by combining the characteristics of antigen and pathogen, which is the key criterion for vaccine success.

He Qinghua, a first-class inspector of National Health Commission CDC, said that Covid-19 vaccines currently listed in China have been examined and approved by the drug regulatory authorities, and their safety and effectiveness are supported by certain data, so you can safely vaccinate them.

How to choose single needle and double needle?

Shao Yiming, a researcher at the China Center for Disease Control and Prevention, said that it is more suitable to inject a single-needle adenovirus vector vaccine for people who have temporary or urgent tasks but do not have enough time to wait. In addition, single-needle inoculation can avoid the poor immune effect caused by failure to get the second needle for various reasons.

Single-needle vaccine also has shortcomings. Shao Yiming suggested that the immune response intensity induced by single-needle adenovirus vector vaccine is generally weaker than that induced by two-needle vaccine, and it is no problem in preventing early epidemic virus. When it is replaced by late mutant virus, the protection efficiency will mostly decrease. Therefore, when choosing a vaccine, we should make a comprehensive judgment and scientific decision according to the specific situation of the people to be protected and the latest monitoring data of local epidemic viruses. (Reporter Shen Shaotie)