The authoritative answer to five questions about sequential booster immunization of COVID-19 vaccine is here.
Xinhua News Agency, Beijing, February 28th Title: The authoritative answer to the five questions of COVID-19 vaccine sequential immunization is here.
Xinhua News Agency reporter Dong Ruifeng and Song Chen
Recently, China began to deploy COVID-19 vaccine to strengthen immunization in sequence. What is sequential booster immunization? The third injection has been given. Do you want to strengthen immunization in sequence? In response to public concerns, experts from the State Council Joint Prevention and Control Mechanism gave authoritative answers.
What is sequential immunization?
Wang Huaqing, chief expert of immunization program of China CDC, explained the concept of "sequential immunization", that is, a strategy of vaccinating vaccines with different technical routes at a certain time interval and dose, in order to improve the preventive effect or further reduce the risk of serious adverse reactions.
Shao Yiming, a member of the expert group of vaccine research and development class of the State Council Joint Prevention and Control Mechanism, said that for viruses with strong variability and difficult to deal with, sequential immunization will be adopted.
Why start sequential booster immunization?
In order to cope with the changes in Covid-19 and improve the effectiveness of the existing COVID-19 vaccine, the World Health Organization currently supports flexible homologous and heterologous vaccination programs. For countries considering heterogeneous vaccination, it is recommended to adopt COVID-19 vaccine with different technical routes from the first vaccination for subsequent doses.
Shao Yiming introduced that the sequential immunization with COVID-19 vaccine has two main purposes: one is that different vaccines can complement each other, and the other is that different people have different constitutions, which may have more side effects on a certain type of vaccine, and adopting different technical routes for vaccination can avoid side effects.
Wu Liangyou, deputy director of the CDC of the National Health and Wellness Commission, said that the research data show that both homologous and sequential immunization can further improve the immune effect.
What are the conditions for sequential booster immunization?
Wang Huaqing introduced that there are four important conditions for the sequential immunization of COVID-19 vaccines:
First, the target of this sequential booster immunization is people over 18 years old.
Secondly, the vaccinated object must meet the conditions of having completed two doses of inactivated vaccine inoculation, and these two doses were inoculated with Covid-19 inactivated vaccine from Sinopharm Zhongsheng Beijing Company, Beijing Kexing Company and Sinopharm Zhongsheng Wuhan Company.
Third, two doses of inactivated vaccine should be inoculated in the whole process, and the inoculation interval should not be shorter than 6 months.
Fourth, the vaccinated subjects have not been vaccinated, that is, they have not received the third injection.
Inoculating inactivated vaccines from different manufacturers in COVID-19, is it a sequential booster immunization?
Wang Huaqing said that vaccines with the same technical route, but with different manufacturers, do not belong to sequential immunization.
For example, the first two vaccinations were COVID-19 inactivated vaccine from one manufacturer, and the third one was COVID-19 inactivated vaccine from another manufacturer, which are all vaccines with the same technical route and do not belong to sequential booster immunization.
The third injection has been given. Do you want to strengthen immunization in sequence?
Wang Huaqing introduced that the group that had already completed the booster immunization before the start of the sequential booster immunization, according to the current regulations, there is no need to carry out the sequential booster immunization in the future.
Specifically, if two doses of inactivated COVID-19 vaccine were given in the early stage, and the third dose of inactivated COVID-19 vaccine was given at a prescribed interval of more than 6 months, it is not necessary to use sequential immunization to strengthen it in the follow-up. If two shots of inactivated vaccine are given in the early stage and the third shot is prepared, you can choose vaccines with different technical routes for sequential booster immunization, or you can choose inactivated vaccines with the same technical route for booster immunization.