In light of the recent outbreak of measles, which has now grown to more than 150 cases, we have been asked an increased number of questions about the safety of the MMR vaccine (measles-mumps-rubella) for patients with egg allergy. These questions stem from the fact that measles and mumps vaccine viruses are grown in chicken embryo fibroblasts. However, it is a misconception that the virus is grown inside of actual eggs.
The recommendations of the Advisory Committee on Immunization at the Centers for Disease Control (CDC) and the American Academy of Pediatrics (AAP) acknowledge that the MMR vaccine can be safely administered to all patients with egg allergy, without the use of special protocols or desensitization procedures. These recommendations have been based, in part, on scientific evidence that supports the routine use of one-dose administration of the MMR vaccine to patients with an egg allergy. This includes those patients with a history of severe, generalized anaphylactic reactions to egg. Additionally, egg-allergic children may be vaccinated with MMR without prior skin testing.
While there have been very rare allergic reactions to the vaccine, these reactions are not believed to be caused by egg antigens, but by other components of the vaccine such as gelatin.
If you have additional questions about you or your child receiving the MMR vaccine, please consult with your allergist.