There is no specific requirement for how late the third dose of the new coronavirus vaccine can be delayed, and it is generally recommended that it be given as early as possible within the required range for optimal prevention. The new crown vaccines that require a third dose are divided into two categories: recombinant subunit vaccines and inactivated vaccines, which are designed to prevent novel coronavirus pneumonia. The recommended interval between 2 adjacent doses of recombinant subunit vaccine is ≥4 weeks. The second dose of vaccine should be given within 8 weeks of the first dose, and the third dose of vaccine should be given within 6 months of the first dose. The recommended interval between 2 doses of inactivated vaccine is ≥3 weeks, with the second dose completed as early as possible within 8 weeks, and the third dose requires an interval of more than 6 months between the second and third doses of inactivated vaccine, as specified in the New Crown Vaccination Guidelines. For those who have not completed the vaccination according to the program, early catch-up vaccination is recommended. It is not necessary to start the immunization program again, and it is sufficient to complete the corresponding dose of vaccine. It is recommended that vaccinators strictly follow the local requirements for vaccination, which will usually be prompted by SMS. If you are unable to receive the vaccine on time, you need to confirm with the local CDC and do not treat it arbitrarily. Tips] The “new coronavirus pneumonia” mentioned in this article has been renamed to “new coronavirus infection” on December 26, 2022, as announced by the National Health Commission.