Authorities explain China Covid-19 vaccine in detail.

Xinhua News Agency, Beijing, April 12 (Reporter Peng Yunjia, Xu Penghang) According to the latest news from National Health Commission, the total dose of vaccination in Covid-19, China is the second in the world. He Qinghua, the first-class inspector of National Health Commission CDC, said that all the four vaccines listed conditionally in China were safe and effective after being examined and approved by the government authorities.

Zheng Zhongwei, head of the vaccine research and development working group of the State Council Joint Prevention and Control Mechanism, believes that the very important indicators for evaluating a vaccine include "four characteristics", namely, safety, effectiveness, accessibility and affordability, of which safety and effectiveness are the two most important indicators.

"The data of protection efficiency of a vaccine in phase III clinical research is based on the field conditions of clinical research and the clinical research plan, and the ratio calculated based on the incidence of vaccine group and control group at a specific time node." Liu Peicheng, a spokesperson for Kexing Holding Biotechnology Co., Ltd., said that its meaning refers to the probability that the vaccinated group has a reduced risk of illness compared with the unvaccinated group.

What factors affect the protection efficiency of vaccines? Liu Peicheng said that the vaccine protection efficiency will be affected by many factors, such as the epidemic intensity of local diseases, vaccine immunization procedures, different epidemic strains, the criteria for judging cases, the age range of observation, and so on, which is one of the reasons why the Covid-19 vaccine of Beijing Kexing Zhongwei has different protection efficiency in clinical research in different countries.

A few days ago, the World Health Organization said that two Covid-19 vaccines developed by Sinopharm Group China Bio and Beijing Kexing Zhongwei respectively have entered the final stage of WHO’s emergency use authorization evaluation, and the relevant data of two Covid-19 vaccines submitted by them show that their protective efficacy meets WHO requirements.

"Up to now, Kexing Zhongwei’s inactivated COVID-19 vaccine has been inoculated nearly 130 million times in the world." Liu Peicheng introduced that in the phase III clinical studies in Brazil, Indonesia, Turkey and Chile, the number of cases in the vaccine group was much lower than that in the placebo group, and there were no hospitalizations, severe cases and deaths in the vaccine group. In addition, the antibody-dependent enhancement effect of the vaccine was not observed in clinical research, emergency use or large-scale use after conditional marketing.

"Vaccination has two protective effects." Wu Zunyou, chief expert of epidemiology at China CDC, introduced that the first is the protective effect on vaccinated individuals; Second, when the vaccinated individuals reach a certain proportion, they can form protection for the group, that is, group immunity.

He said that only when the vaccination rate in Covid-19 reaches 70% and 80% of the population can it produce group protection effect, otherwise it can only protect individuals and cannot produce group immunity. "This is also why the whole world is vigorously promoting vaccination, and it is necessary to achieve the coverage required for mass immunization coverage before the next epidemic peak in autumn and winter."

Five vaccines have been approved for conditional marketing or emergency use in China. Wang Huaqing, chief expert of immunization program of China CDC, said that the mRNA vaccine developed in China has also entered the clinical trial stage.

At present, all parts of the country are doing a good job in the vaccination of people in key areas and key industries according to the principle of "taking all the connections, advancing step by step, highlighting key points and ensuring safety", and carrying out vaccination in large and medium-sized cities, port cities and border areas with high risk of epidemic situation.

Beijing, Shanghai and other regions have begun to provide vaccination services for some elderly people over 60 years old and patients with chronic diseases who are willing to vaccinate and have good physical condition on the premise of fully evaluating the health status and infection risk of the vaccinated objects.

"At present, the vaccination work in Covid-19 is progressing smoothly." Wu Liangyou, deputy director of the National Health Commission Municipal Bureau of Disease Control and Prevention, said that it is necessary to adhere to the principle of combining "taking everything" with the principle of voluntariness, and on the basis of full notification, guide and encourage the masses to actively vaccinate and take the initiative to achieve "taking everything" and effectively improve their sense of acquisition, happiness and security.

"In response to the COVID-19 epidemic, vaccines are a very important prevention and control strategy." Wu Zunyou said that the global COVID-19 epidemic is still in the high-level epidemic stage, and the risk of local epidemic spread caused by overseas imports still exists. Timely vaccination is to protect the public.