The third dose of recombinant New Crown vaccine (CHO cell) is recommended to be completed within 6 months after the first dose. For inactivated vaccines, there is no strict minimum vaccination requirement for the third dose (booster). Recombinant New Crown Vaccine (CHO Cell) is divided into 3 doses, and there should be an interval of more than 4 weeks between the 3rd and 2nd doses. If vaccination needs to be delayed due to special reasons such as pregnancy, acute stage of chronic diseases, etc., it is recommended to make up the vaccination as early as possible, and the 3-dose vaccination should be completed within 6 months after the 1st dose if there is no special reason. If a booster shot of the new crown vaccine is to be given, there is no strict requirement on the latest time of vaccination, but it is necessary to complete 6 months after the completion of the full immunization before vaccination.