Class I vaccine is the vaccine that infants and young children must be vaccinated, and others can choose to receive Class II vaccine at their own expense according to their actual situation. One type of vaccine is free vaccine for infants and young children, which belongs to the national immunization plan vaccine, hepatitis B vaccine three doses, BCG vaccine one dose, polio vaccine four oral doses, DPT vaccine five doses, measles vaccine two doses, including hepatitis A vaccine, influenza vaccine, encephalitis B vaccine, hemorrhagic fever vaccine and so on. The second type of vaccines for infants and young children are self-funded vaccines, including chickenpox vaccine, inactivated hepatitis A vaccine, influenza vaccine, rabies vaccine, Haemophilus influenzae type B vaccine, oral rotavirus vaccine, pneumonia vaccine, etc., which can be chosen according to one’s own actual situation. Regular vaccinations for infants and young children can effectively prevent many kinds of diseases, and are the most effective means of protecting the physical health of infants and young children.