Clinically, the composition and dose of the first and second doses of the new crown vaccine are the same. It is recommended to try to receive the same type and manufacturer of vaccine, or to ensure that the type is the same if the same manufacturer of vaccine is not available at the moment. There are also applications that require 3 doses of the recombinant New Crown vaccine. The composition and dose of multiple doses of the vaccine are generally the same, but the number of doses varies and the rate of protection is not exactly the same. The first dose of the new crown vaccine is used as basic immunity to induce an immune response in the body, and the second dose is used as booster immunity to make the antibody positivity rate in the body higher and the protection effect on the body stronger. The interval between 2 doses of Neocrown inactivated vaccine generally needs to be >3 weeks, and it is recommended that the 2nd dose be completed within the 8th week. People who are allergic to any component of the vaccine, are in a febrile state or have severe neurological disease, or are pregnant should not be vaccinated and can be re-evaluated if their disease status improves. Those who have not completed the two doses of vaccination within the prescribed period can consult with the vaccination site for a replacement vaccination as soon as possible, and those who are eligible can complete the vaccination procedure as soon as possible.