MMR vaccine and B brain vaccine together will not produce too serious adverse reactions, some children may have fever, skin rash, etc., which will usually subside on their own. MMR vaccine belongs to Class I vaccine, which is given to children at eight months and eighteen months of age respectively; B vaccine is divided into live attenuated B vaccine and inactivated B vaccine, live attenuated B vaccine is given to children at eight months and two years of age; inactivated B vaccine is given to children at eight months of age twice, and then at two weeks of age and six years of age once again. MMR vaccine and Brain B vaccine vaccinated together will not cause too much adverse reaction to children, and they can choose to be vaccinated in different locations or at different intervals. Some children may have adverse reactions such as fever and rash after vaccination, so they can stay at the place of vaccination for half an hour after vaccination, and the symptoms will usually subside by themselves.