Vaccination is an artificial active immunity, which is the input of antigenic substances, such as vaccines, vaccines and toxoids, into the body by artificial inoculation to stimulate the body to produce specific immunity on its own initiative, and is mainly used for specific prevention of diseases. Babies can acquire some resistance to infectious diseases from their mothers after birth, but this resistance will gradually weaken or even disappear as they grow older, so children should receive various vaccines according to the regular immunization program from birth to prevent various infectious diseases.