Supplemental vaccinations are recommended if the vaccine has not been administered for more than 2 months. In general, there is some variability in the timing of vaccinations and the number of shots given depending on the type of vaccine. There are some vaccines that may require a fixed time for injection; common ones such as BCG and Hepatitis B vaccines need to be administered at birth. If for other reasons the vaccination has not been given for more than 2 months, it is recommended that you contact your local vaccination office in a timely manner in order not to affect your child’s future schooling. In addition, there is no strict age limit for most other vaccines, so if you have not received a vaccination in time, it is recommended that you get a catch-up vaccination in time. In addition, for epidemic prevention and control work, it may be necessary to receive the new crown vaccine. If you receive multiple doses of the vaccine, and the second or third vaccine has not been given for more than 2 months, it is a case of not completing the vaccination according to the procedure, and it is recommended to make up the vaccination as soon as possible. It is not necessary to restart the immunization process, but to complete the corresponding doses. It is recommended to pay attention to the vaccination schedule and try to complete the vaccination within the specified time to avoid affecting the protective effect of the vaccine.