Vaccination is also known as vaccination, vaccination has time requirements, without a certain interval, temporarily can not be vaccinated with the next vaccine. Children are the main population of vaccination, small children vaccination time, mainly in accordance with the provisions of the Ministry of Health to implement the children’s program of immunization, vaccination is a time requirement, did not reach a certain interval, temporarily can not go to the next vaccination. There are more types of vaccines, such as hepatitis B vaccine and BCG vaccine for newborns, a second dose of hepatitis B vaccine for babies at one month, polio vaccine at two months, DPT vaccine and polio vaccine at three months, according to the different ages of different vaccines at different ages, and there are also different vaccination times. The time of vaccination cannot be advanced, and the next vaccine cannot be given without a certain interval. It is recommended to go to a regular vaccination center to learn about vaccination.