CCB, Beijing, August 27 (Reporter Lin Mengxi) On the afternoon of the 27th, the Joint Prevention and Control Mechanism of the State Council held a press conference on further efforts to prevent and control the epidemic and vaccination.

Zheng Zhongwei, head of the Vaccine Research and Development Special Team of the Joint Prevention and Control Mechanism Research Team of the State Council, and director of the National Health and Health Commission's Medical and Health Science and Technology Development Research Center, responded to the recent concern about the new crown vaccine booster injection and other related issues.

　　People over 60 years old and at high risk of importing can be vaccinated with the new crown vaccine booster

　　As the epidemic rebounded, the media reported too many cases of infection after vaccination at home and abroad.

In this regard, the new crown vaccine booster has also attracted more and more attention.

　　According to Zheng Zhongwei, as of yesterday, the cumulative number of new crown vaccines in the world has exceeded 5 billion doses, of which more than 2.5 billion doses of China's new crown vaccine have been vaccinated globally.

According to statistics, the anti-infection protection rate of China's new crown vaccine currently on the market ranges from 50% to 90%.

　　Recently, the vaccine research and development class also organized experts to combine the two vaccines of Sinopharm Zhongsheng and Beijing Kexing to conduct special research on whether to carry out intensified vaccination.

The study found that 6 months after the two vaccines were vaccinated, the antibodies of the recipients had decreased to varying degrees, but this was in line with the rules of conventional vaccines.

At this time, the third dose of vaccination, the recipient's antibody level will rise after 3 days, and reach a higher level after 7 days. At 14 days, the antibody can reach 15 to 30 times the original level.

When tested again 6 months later, the antibody will still decline, but the low point it drops to exceeds the peak after 2 doses of vaccination.

Therefore, from the perspective of immunogenicity, the protective effect of the booster vaccination on the vaccine can be improved.

　　At the same time, there are also people with relatively low immune function in routine vaccination, and people over 60 years of age have less immune effects after vaccination than those aged 18-59.

But this kind of population is precisely the high-risk population after infection, and the risk of severe, critically ill, and death after infection is higher than that of other populations.

Therefore, experts also suggest that for these people, a booster shot can be given 6 months after vaccination.

In addition, experts also suggest that people who go to overseas high-risk areas or countries due to work, study, and communication can also carry out booster vaccination after 6 months of vaccination.

However, at this stage, whether to carry out booster immunization for the entire population 6 months after vaccination, experts suggest that further research is needed, and a comprehensive study and judgment should be made based on the situation of the epidemic.

　　People who have been vaccinated do not need to be tested for antibodies

　　At present, many people are worried that the level of neutralizing antibodies will decline after vaccination with the new crown vaccine and lose their protective effect, so they hope to be tested.

Zheng Zhongwei responded by saying that "it is neither necessary nor feasible."

　　Zheng Zhongwei said that the results of clinical trials show that the new coronavirus vaccine has strong immunogenicity.

After vaccination, the positive conversion of neutralizing antibodies has reached more than 90%. At the same time, after vaccination, it can stimulate the human body. In addition to the production of neutralizing antibodies, it will also produce cellular immunity and immune memory.

The gradual decline in antibody levels after vaccination is a natural response of the human immune system, but it does not mean that the vaccine has lost its protective effect.

　　The previous normal vaccines did not carry out human antibody testing, and there were no legal requirements in this regard.

According to Zheng Zhongwei, to judge whether a vaccine is effective, it is mainly through the preliminary clinical trials and the later stage based on the real-world study of the large-scale epidemic. It is not possible to simply judge whether the vaccine is effective or protective based on the level of neutralizing antibodies. .

Therefore, at this stage, it is neither necessary to carry out large-scale population antibody testing, nor is it feasible.

　　Multi-country clinical studies show the effectiveness of China's vaccines

　　So far, my country has provided more than 800 million doses of vaccines to the world, especially developing countries, and many countries have also carried out corresponding large-scale vaccination.

　　Zheng Zhongwei said that since May, Peru, Thailand, Chile, Argentina, Mongolia, Bahrain, Uruguay, Sri Lanka and other countries have been vaccinated with my country's new crown inactivated vaccine on a large scale. Some of these countries have also released relevant real-world research data.

However, due to the different prevention and control strategies of various countries, the prevalence of mutant strains is also different, so the relevant data released are also different.

Overall, the protection rate against infection ranges from 57% to 85%, the average protection rate against severe illness is around 90%, and the protection rate against death is between 84% and 97%.

　　The Chilean Ministry of Health published the research results of Coxing Zhongwei inactivated vaccines in the New England Journal of Medicine. It is the largest real-world data published in medical journals in the world so far, with a sample size of more than 10 million people.

The conclusion of the study is that China's new crown vaccine has a 65.9% protection against infection, an 87.5% protection against hospitalization, a 90.3% protection against severe illness, and an 86.3% protection against death.

　　According to a report from the Peruvian Ministry of Health, 60,593 doctors were vaccinated with Sinopharm’s inactivated vaccine. The report showed that after the completion of two doses of vaccination, the mortality rate of medical staff belonging to the high-risk population dropped by 98%.

　　The Argentine Ministry of Health conducted an age-by-age study on people over 60 years of age who had received two doses of Chinese biologically inactivated vaccines, and issued a related report.

The results show that the overall protection rate is 84%, of which the protection rate for people between 60 and 69 years old is 80.2%, the protection rate for people between 70 and 79 years old is 88.3%, and the protection rate for people over 80 years old is 77.6%.

　　The Sinopharm Inactivated Vaccine Research Report released in Sri Lanka also showed that the antibody titers of the vaccinators to Delta virus dropped by 1.38 times, which still has a good protective effect on Delta virus.