No matter which new crown vaccine, as long as it is approved for marketing in China, it is safe and effective, and there is no difference between good and bad; however, for special populations such as children, care needs to be taken to avoid certain types of vaccines. The brand of vaccine only represents the difference of manufacturer, the specification and production standard of each vaccine have strict requirements. Usually, inactivated virus vaccine, adenovirus carrier vaccine and other vaccines approved for use in our country have the ability to prevent viruses, and there is no difference between good and bad vaccines. The difference between inactivated virus vaccine and adenovirus vector vaccine is mainly the different preparation methods, which can prevent diseases. The active ingredient of adenovirus vector vaccine is mainly the nucleic acid fragment of the virus; the main ingredient of inactivated vaccine is the new coronavirus cultured in vitro, which has been killed, and the inactivated vaccine is relatively less irritating and suitable for children. Therefore, for special populations (such as children), due to the differences in their own physiological characteristics, there are contraindications in the selection of vaccines. Currently, the vaccine approved for emergency use in children is the inactivated New Coronavirus vaccine, which is usually administered in two doses, and a third dose is not recommended for children to enhance immunity. It is advisable to consult the relevant medical institutions to decide whether or not you can be vaccinated and what kind of vaccine you should receive.