China News Service, April 21. The State Council's Joint Prevention and Control Mechanism held a press conference on the new crown vaccination situation on the 21st.
Talking about the topic of reactions after vaccination, Wang Huaqing, chief expert of the Chinese Center for Disease Control and Prevention's immunization program, said that adverse reactions are related to the characteristics of the vaccine, the person's age, health, and past allergies.
At the meeting, a reporter asked questions and said that some people may experience discomfort after receiving the new crown vaccine, or suspect that they have an adverse reaction. What factors affect the adverse reaction of the vaccine?
If there is an adverse reaction, will it affect the effect of vaccination?
Wang Huaqing said that after vaccination, some people will experience adverse reactions.
In fact, the occurrence of adverse reactions is related to the characteristics of the vaccine and also to the individual's special physique.
Like in the past, when vaccinated with live attenuated leprosy and mumps vaccine, its fever may appear one or two days after vaccination, and some may appear in about a week.
Why is such a fever process possible?
It is related to the characteristics of live attenuated vaccines.
There are also DPT vaccines, which used to be whole-cell DPT vaccines, but now use acellular DPT vaccines and component DPT vaccines. The incidence of adverse reactions has been greatly reduced, because it The antigen component of the vaccine is smaller, or its antigen component is more pure. These adverse reactions are related to the characteristics of the vaccine.
Wang Huaqing pointed out that sometimes it is also related to individual differences, such as age.
"Why this time I saw that during the clinical trials of the new crown vaccine or during the post-marketing monitoring process, some young people had higher adverse reactions, and the elderly had lower adverse reactions? This also has a lot to do with his physique. Like sometimes If there is a serious allergy, we said that we should not rush to get another vaccination. This has a lot to do with his allergies after he was exposed to the allergen in the early stage.
Wang Huaqing said that in order to ensure the safety of vaccination for some people with immunodeficiency, it is actually recommended that people with immunodeficiency should not receive live attenuated vaccine in principle. Because of this constitution and disease state, they will be vaccinated after vaccination. There is a risk.
In order to reduce the risk or control the risk, in principle, these people with immunodeficiency should not be vaccinated with live attenuated vaccines, and inactivated vaccines should be used instead.
"This means that the situation of adverse reactions is related to the characteristics of its vaccine, as well as factors including the person's age, health status and previous allergic history. So when it comes to the occurrence of adverse reactions, we also adopt Measures, especially serious adverse reactions, can reduce this to a minimum level, further control the risk, and make vaccinated people safer to get the vaccine." Wang Huaqing said.