Boosting needle refers to the dose of vaccine that is vaccinated again according to the fading of antibody after vaccination, so as to maintain the immunity of human body to virus. The booster needle is also used for other vaccinations, such as polio vaccine and DTP vaccine.

At present, there are 2 shots of inactivated vaccine in COVID-19, and one shot of adenovirus vector vaccine in COVID-19 1 shot, 18 years old and above who have completed the whole vaccination for 6 months, so as to improve the antibody level.

Why should I get a booster shot? What is the effect after vaccination?

From the existing observation and research, COVID-19 vaccine has a remarkable effect in preventing severe illness and death after the whole vaccination. However, after inoculation for a period of time, the immunity of some people decreased and the protective effect weakened. A booster vaccine can make this weakening "strongly rebound".

According to some data, the antibody level increased by more than 10 times after the second dose of domestic inactivated vaccine was inoculated for half a year.

The results of intensive immunization study of inactivated vaccine in COVID-19 carried out by related enterprises showed that the antibody of inactivated vaccine in COVID-19 decreased in different degrees after 6 months of inoculation, which was the same as that after routine inoculation. After intensive immunization, the antibody level of the recipient will rise or rebound rapidly. After 14 days of intensive immunization, the antibody level was equivalent to the original 10-30 times. After 6 months, although the antibody level also decreased, it was still higher than the peak after two doses of inoculation or 1 dose, which could maintain a high level and had a good cross-neutralization effect on mutants such as Delta.

How to choose a booster vaccine?

Give priority to the use of vaccines produced by the original inoculation enterprises, that is, people who have completed two doses of vaccination with the same inactivated vaccine, in principle, use the original inactivated vaccine for 1 dose to strengthen immunization; In principle, people who have completed two doses of vaccination with different inactivated vaccines should give priority to using the same vaccine as the second dose of inactivated vaccine for 1 dose to strengthen immunization. If they can't provide a second inactivated vaccine, they can use the same vaccine as 1 dose. People vaccinated with adenovirus vector vaccine should be given enhanced immunization with the original vaccine.

Is it safe to inject booster vaccine?

Safe. According to experts' introduction, combined with the research results of relevant enterprises on strengthening immunization of COVID-19 vaccine, it was found that the second or third injection of strengthening immunization was still as safe as the first and second injections.