My 4 year old had a very strong reaction to a vaccine this year and had to be transferred by ambulance. We have an appointment to special center where they test

My 4 year old had a very strong reaction to a vaccine this year and had to be transferred by ambulance. We have an appointment to special center where they test the vaccine's different components separately. Maybe that could be another option in your case too. His next vaccine is only at 12 so we could just do nothing but we want to know if tetanus shots could be the culprit because they are often administered following an accident.