Chow WC, Kwan EYW, Lau YL

Department of Paediatrics, University of Hong Kong, SAR, China


Objective: Measle virus in MMR or single measle vaccines are grown in culture of fibroblasts from chick embryos. Small amount of egg protein is present in the vaccine. First Anaphylactic reaction to MMR was first identified in 1983 and was associated with the egg allergy. However, recent studies did not confirm a definite causal relation of the egg allergy and MMR anaphylaxis. The objectives of this study were to evaluate the recommendations of MMR vaccination of children known to be allergic egg, and to document any association between egg allergy with MMR vaccine anaphylaxis in our locality.

Methods: This study was a retrospective review of all patients admitted into our hospital for MMR vaccination during the period of Jan. 1996 to Dec. 2000.

Results: 146 patient records were reviewed and the male to female ratio was 79/67. Only 96 patients got history of egg allergy. Most of them did not know whether they were sensitive to egg white or egg yolk. Seven cases out of the 96 patients showed anaphylactic reaction to egg component. Others suffered from minor reactions such as rash or urticaria. All patients were given MMR vaccine and none of them developed anaphylaxis. Only two patients got non-specific rash soon after the injection. All cases were discharged on the same day after the injection and no mortality detected.

Conclusions: MMR vaccination is as safe as any other vaccine and allergy to eggs should not delay measle vaccination. Children with milder forms of allergy can be safely vaccinated without additional precaution. All vaccination must be carried out in setting equipped to deal with anaphylactic reaction. Further investigation and formation of registry with full reporting of allergy and reaction clearly defined would be most helpful in understanding  the causes of MMR allergy.