According to the instructions of the Technical Guideline for Vaccination against New Coronavirus (First Edition) issued by our Health Care Commission, if the vaccination is the second dose of inactivated new coronavirus vaccine, the time of vaccination can start from the 21st day after the first dose, and the recommended time of vaccination for the second dose is between 21 and 56 days after the first dose of vaccine, and either early or late in this time range will not affect the vaccination effect. Generally speaking, the second dose of inactivated neo-coronavirus vaccine is given on the second day after the first dose, which is the first day of vaccination, and then 21 days later. The Technical Guide to Neocoronavirus Vaccination (First Edition) also emphasizes that those who have completed two doses of inactivated neocoronavirus vaccine within 14 days will need to receive a new dose of inactivated vaccine 21 days after the second dose. For those who completed two doses of inactivated neo-coronavirus vaccination between 14-21 days, no catch-up vaccination is required. Therefore, there is no problem to receive the second dose later than 21 days, but not too early. In addition, if the vaccination is recombinant neocoronavirus vaccine, three doses need to be administered with an interval of 28 days between them, and the third dose needs to be completed within 6 months after the first dose. If acute diseases such as fever or diarrhea occur during the vaccination with the new coronavirus vaccine, or if patients have chronic diseases but are in the acute onset, the vaccination can be postponed to avoid aggravating the discomfort after vaccination.