October 23, 2020
MMR vaccine
Question
When administering MMR vaccine, is there any concern with patients that have either egg allergy, latex allergy, or gelatin allergy? How would you go about testing for these allergens in MMR vaccine?
Answer
Anaphylaxis following vaccines is rare, occurring at a rate of approximately one per million doses for many vaccines. The MMR (measles, mumps, and rubella) vaccine is generally considered safe for children with egg allergy because modern MMR vaccines are grown in chick embryo fibroblast cultures containing insignificant or no egg protein.
Allergic reactions to vaccines due to natural rubber latex in vial stoppers or siringe plungers rarely occur. According to the FDA website, the MMR vaccine marketed in the United States does not contain latex in the packaging (www.fda.gov/BiologicsBloodVaccines/Vaccines/ApprovedProducts/ucm093833.html).
Gelatin, which is added to many vaccines as a stabilizer, is probably responsible for the majority of allergic reactions to the MMR vaccine. It should be noted that Priorix® brand does not contain gelatin.
Patients with a history of an immediate allergic reaction following the ingestion of gelatin should be carefully evaluated by an allergist prior to the administration of any gelatin-containing vaccine like MMR and varicella. Allergy testing to gelatin is based on:
If a patient reports a previous allergic reaction after receiving the MMR vaccine, it is imperative to assess the severity of the reported reaction and carefully evaluate the risk-benefit of a new dose. If benefit outweighs risk, prior skin testing with the full vaccine is recommended in the following steps:
After a thorough allergy approach, there will be cases where the risk of anaphylaxis from an additional MMR vaccine will outweigh the benefit. These patients must be treated by multidisciplinary teams involving infectious disease and immunology physicians.
On the other hand, some patients will require the administration of MMR vaccine in gradual doses. This should be directed by experienced allergists in appropriate healthcare settings, prepared to rapidly detect and treat anaphylaxis.
References
Mariana Gálvez, MD
Allergy and Clinical Immunology
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