Generally speaking, babies are two months old to start receiving the DPT vaccine. Pentavalent vaccine is an inactivated vaccine, including polio vaccine, DPT vaccine and Haemophilus influenzae vaccine, preventing five kinds of infectious diseases, and its advantage is that the number of times of inoculation is less, and the pain of children will be less. The vaccination program in mainland China generally recommends two months of age, three months of age, four months of age, for children with diseases that cause delay can also be three months of age, four months of age, five months of age to vaccinate. Overseas, the Pentavalent vaccine is given at two, four and six months of age, so there is a slight difference.