◎ Science and Technology Daily reporter Zhang Jiaxing
"Recently, with the approval of the joint prevention and control mechanism of the State Council, the National Health Commission has begun to deploy a sequential strengthening of immunization." At the press conference of the joint prevention and control mechanism of the State Council on February 19, Wu Liangyou, deputy director of the Disease Control Bureau of the National Health Commission, introduced that according to the progress of the development and use of the new crown virus vaccine, the vaccination strategy has been further supplemented and improved.
Image source: China Net Live
Sequential booster immunization refers to the selection of a COVID-19 vaccine that is different from the inactivation technology route when strengthening immunization. Previously, the mainland has been implementing a homologous vaccination strategy to strengthen immunization, that is, the booster needle must choose the same technical route of the new crown vaccine for vaccination.
Sequential booster immunization means that boosters can choose between recombinant protein vaccines and adenovirus vector vaccines. Wu Liangyou said that after the implementation of the sequential strengthening immunization strategy, the target population of the inactivated vaccine of Sinopharm Zhongsheng Beijing Company, Wuhan Company and Beijing Kexing Company can be completed, and the recombinant protein vaccine of Zhifeilong Koma or the adenovirus vector vaccine of CanSino can be selected for sequential enhancement of immunization.
Who is eligible for vaccination?
Under the deployment of the new sequential booster immunization, not all people are suitable for sequential immunization. So who can choose vaccines with different technical routes as booster vaccinations?
Wang Huaqing, chief expert of the immunization program of the Chinese Center for Disease Control and Prevention, said that the object of this sequential immunization has three conditions, one is for people over 18 years old, and the other is to complete 2 doses of inactivated vaccination according to the procedure, and the vaccine is one of the three inactivated vaccines of the new crown virus in China National Medicine Zhongsheng Beijing Company, Beijing Kexing Company, and Sinopharm Zhongsheng Wuhan Company. Third, there is no booster immunization, that is, the third injection is not given.
Wang Huaqing reminded that after vaccination, it is necessary to stay for 30 minutes, and when there is an adverse reaction suspected of being related to vaccination, if the duration is long and the symptoms are more serious, one is to report to the vaccination unit, and the other is to seek medical treatment in time.
Why sequential immunization?
Before the enhancement of the needle needed to be consistent with the previous vaccine technology route, now it can be different, why is this?
Shao Yiming, a member of the vaccine research and development expert group of the scientific research group of the joint prevention and control mechanism of the State Council, said that according to the previous experience in the prevention and control of infectious diseases, a single vaccine can deal with conventional viruses, but for the cunning viruses that are good at mutation, different vaccines can be implemented "joint operations".
"Sequential immunity has two advantages." Shao Yiming explained: First, different vaccines can complement each other's advantages, and the other is that for some people, side reactions can be reduced, due to different human physiques, people who may have side reactions to a certain vaccine are heavier, and they can be transformed by vaccines to reduce the occurrence of side reactions.
In response to the Omilon, there is a greater need for enhanced immunization
Omikeron has become a mainstream strain of the global epidemic. Wu Liangyou said that at present, the Aumechjong variant strain has become the dominant strain of imported and local epidemics outside the mainland, its transmission force is stronger, the transmission speed is faster, and the risk of overseas imported epidemics and local epidemics in the mainland has increased significantly.
In response to the coronavirus mutation, the World Health Organization supports flexible homologous vaccines and heterologous vaccination programmes. Wang Huaqing introduced that based on the research evidence, some countries in the Americas, Europe and Southeast Asia have begun to implement a sequential strengthening of immunization.
"The research data shows that homologous enhanced immunization and sequential enhanced immunization can further improve the immunization effect, and people who hope to meet the vaccination conditions can take the initiative to vaccinate and vaccinate early." Wu Liangyou said.