There are two types of encephalitis B vaccines: inactivated encephalitis B vaccine and live attenuated encephalitis B vaccine. The target of vaccination is children above 6 months of age, and the live attenuated B brain vaccine is given in two doses, one dose at 8 months of age and one dose at 2 weeks of age; the inactivated B brain vaccine is given in four doses, two doses at 8 months of age, with an interval of 7-10 days, and one dose at 2 years of age and one dose at 6 years of age. In addition to the history of allergy, inactivated vaccine should not be injected, fever, other acute and chronic diseases and neurological diseases can not be vaccinated; live attenuated vaccine, in addition to the above contraindications, immunodeficiency, or recent immunosuppressive treatment or the use of drugs related to the suppression of the immune system can not be vaccinated.