Vaccinations of children allergic to eggs with vaccine prepared with egg

Background: The mumps, influenza, yellow fever and measles vaccines are grown in chick-embryos. Because allergic reactions to these vaccines have occasionally been reported in children who have suffered anaphylaxis from egg ingestion, it has been claimed that these children should not receive such vaccines.

Methods: 17 egg-allergic children aged 1 year 1 month to 7 years 10 months (mean 2 years 4 months) were studied. All had developed an allergic reaction less than one hour after egg ingestion. Allergy was confirmed by skin testing (prick skin test) and detection of IgE antibodies to egg (RAST).

Results: Seven children were immunized normally by their general practitioner, who was not aware of their allergy; 8 children having negative prick skin and intradermal tests with the vaccine were also immunized normally while 2 children who had positive intradermal test with the vaccine received divided doses following a protocol established for this study. None of these 17 egg-allergic children developed local and/or general reactions. Reintroduction of egg (yolk then white) was tested on the day of immunization in 4 children: only one developed facial edema.

Conclusions: This protocol permits these vaccines to be safely given to egg-allergic children.