Do You Know How to Recognize a Vaccine Reaction?Do you know how to recognize a vaccine reaction? Like with prescription drugs and other pharmaceutical products, reactions to vaccines can be mild or severe. There can be complete recovery or long lasting health problems after vaccine reactions. Rarely, vaccine reactions can be fatal. If you are making a decision about vaccination for yourself or your child, it is important to first become fully informed about each vaccine’s reported side effects, precautions and contraindications, which means reasons for why a person may be at risk for having a serious reaction. It is especially important for parents to become informed about vaccine complications and how to recognize the symptoms of a vaccine reaction.