During the current New Crown outbreak, the third shot of the New Crown vaccine is generally referred to as the third booster shot of the New Crown inactivated vaccine, or the third shot of the recombinant subunit vaccine is the basic immunization. The third shot is voluntary. The new crown virus vaccination, not a mandatory requirement, is voluntary. At present, there are three main types of vaccines approved and marketed in China, inactivated neocoronavirus vaccine, recombinant neocoronavirus vaccine (adenovirus vector type 5) and recombinant neocoronavirus vaccine (CHO cells). Taking the recombinant Neocoronavirus vaccine (CHO cell) as an example, a total of 3 injections are required. It is recommended that the 2nd injection should be completed as far as possible within 8 weeks after the 1st injection, while the 3rd injection should be administered as far as possible within 6 months after the completion of the 1st injection. Currently, it is recommended to choose vaccines from the same company. If there are special circumstances that make it impossible to complete the vaccination with vaccines from the same company, vaccination can be completed with vaccines of the same type produced by other companies.