In Spain, for many years allergy to eggs was considered to contraindicate vaccines cultured in fibroblasts from chick embryos such as the measles, mumps, rubella (MMR) and influenza vaccines. Consequently, an alternative vaccine (Triviraten Berna) incubated in diploid human cells has been systematically administered to children who are allergic to eggs, without questioning tolerance to the standard MMR vaccine. After Biotech Bern Laboratory discontinued the production of Triviraten, this alternative was no longer available for children with egg allergy, who should receive a first dose of the MMR vaccine at the age of 15 months and a second one (booster dose) at the age of 3 years. In this context, from November 2004 to June 2005, a single dose of the MMR vaccine was administered to 40 children with allergy to eggs and none showed an adverse reaction. We conclude that this vaccine can be safely administered to this group of patients.