After radiotherapy, because the immunity of the child’s body decreases, vaccination within a short period of time can cause related diseases and lead to adverse consequences, and it is recommended that vaccination be given at least three months after radiotherapy. Live attenuated vaccines are often used for domestic vaccination, but inactivated vaccination is preferred for children undergoing radiotherapy. Children with liver and kidney damage should have their liver and kidney functions checked first and then be vaccinated after they are normal. Before and after vaccination, parents should closely observe the child’s condition, and if high fever, skin rash or other adverse reactions occur, promptly go to the hospital.