The Hib vaccine is usually administered to infants and children at different ages, and the exact timing can be flexible. Hib vaccine is the abbreviation of Haemophilus influenzae type B conjugate vaccine, which can effectively prevent the occurrence of meningitis, pneumonia, septicemia and other diseases caused by Hib. 1. Less than 6 months old: Infants less than 6 months old receive 4 doses of Hib vaccine. The first injection is given when the infant reaches 2 months of age, and the following 2 injections are given every 1~2 months, and another Hib vaccination is given in the 2nd year of life. 2. 6 months to 12 months: Infants between 6 months and 12 months of age receive a total of 3 doses of Hib vaccine. Initial Hip vaccination, with a one-month interval between the 2 doses, and another H2B vaccination in the 2nd year of life. 3. Age 1~5 years old: In this age group, infants and young children only need to receive one dose of Hib vaccine. In addition, Hib vaccination is an effective measure to prevent infection, and it is recommended to visit your local CDC for standardized vaccination.