Ask The Expert
October 23, 2020
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?
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:
- Measurement of serum specific IgE to gelatin using commercial assays such as ImmunoCAP®.
- Skin prick test with a non-standardized solution consisting of commercial gelatine powder (5 g) dissolved in 5 ml of physiological saline.
- Oral provocation testing.
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:
- Non-diluted skin prick test (SPT). If negative:
- Intradermal testing with 1/100 dilution in physiological saline.
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.
- Centers for Disease Control and Prevention. General Best Practice Guidelines for Immunization: Best Practices Guidance of the Advisory Committee on Immunization Practices (ACIP). In: https://www.cdc.gov/vaccines/hcp/acip-recs/general-recs/adverse-reactions.html.
- Echeverría-Zudaire, Luis & Ortigosa, Luis & Lebrero, Elena & Álvarez-García, Francisco & Cortés-Álvarez, Nuria & Martorell-Aragonés, Antonio. (2015). Consensus document on the approach to children with allergic reactions after vaccination or allergy to vaccine components. Allergologia et immunopathologia. 43. 10.1016/j.aller.2015.01.004.
- Russell M, Pool V, Kelso JM, Tomazic-Jezic VJ. Vaccination of persons allergic to latex: a review of safety data in the Vaccine Adverse Event Reporting System (VAERS). Vaccine. 2004;23(5):664-667. DOI: 10.1016/j.vaccine.2004.06.042
- Nilsson, L, Brockow, K, Alm, J, et al. Vaccination and allergy: EAACI position paper, practical aspects. Pediatr Allergy Immunol. 2017; 28: 628– 640. https://doi.org/10.1111/pai.12762
Mariana Gálvez, MD
Allergy and Clinical Immunology
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