Vaccinations for babies are recommended to be administered according to the national schedule and are generally not recommended to be postponed without reason. However, if the vaccination is delayed due to special circumstances, the time of postponement varies slightly for different vaccines. If the baby was not vaccinated with Hepatitis B and BCG at birth because of premature birth or low weight, or because of high-risk factors, the vaccination can be postponed until 3 months, and within 3 months, the vaccination can be given anytime as long as the baby is eligible. If more than 3 months old, liver function tests are required first, and hepatitis B vaccination can be given if the liver function is normal. If polio, measles or rubella vaccination is delayed, several vaccines are available at any time as long as the baby is physically eligible. If a baby delays vaccination because of a cold and fever, he or she can be vaccinated 1-2 weeks after healing from the cold, or 4-6 weeks after he or she heals from pneumonia. If the baby has some congenital diseases, vaccination needs to be cautious, such as congenital immunodeficiency, AIDS and other diseases, you need to consult a professional doctor before considering whether to vaccinate. Since infancy is an intensive period for vaccination, if the vaccination is delayed too long, it will easily affect the subsequent vaccination, so parents are reminded that it is best to vaccinate their babies according to the prescribed schedule.