When to get vaccinated is as follows: 1. Vaccination according to the national immunization schedule, such as hepatitis B vaccine and BCG vaccine at birth, the second hepatitis B vaccine at 1 month, polio vaccine at 2 months, polio vaccine and the second polio vaccine at 3 months, etc. The vaccine is given in accordance with the planned immunization schedule. 2. The vaccination time should be chosen when the child is in good health. Vaccination should not be carried out in a state of physical illness or when the immunity is poor, which may lead to side effects of the vaccine, such as abscess infection at the injection site or high fever in the child, which is not conducive to the absorption of the vaccine and also has an impact on the health of the child. Therefore, the timing of vaccination should be based on the immunization schedule and the health condition of the child.