Early catch-up vaccination is recommended for those who have not completed the 2-dose or 3-dose procedure. It is not necessary to restart the immunisation process, but to complete the appropriate dose. For those who have completed 2 doses of inactivated New Coronavirus vaccine within 14 days, catch up with 1 dose of inactivated vaccine as soon as possible, 3 weeks after the second dose. For those who complete 2 doses of inactivated neo-coronavirus vaccine within 14 to 21 days, no catch-up is required.