The infant quadruple vaccine consists of pertussis antigen, diphtheria toxoid, tetanus toxoid, and Haemophilus influenzae type B antigen, four antigens or toxins that are inactivated and purified together. The first vaccination is given at the age of 3 months, the second at 4 months and the third at 5 months, with an interval of at least one month between each vaccination, and a booster at the age of 18-24 months, with an interval of more than 6 months between this and the first vaccination. After vaccination, local redness, swelling, pain, fever, occasional allergic rash, angioedema may occur, and if the systemic reaction is serious, hospital treatment should be promptly sought.