Brief Reports

Flu Vaccine: Does Egg Allergy Matter?

By Carol A. Kemper, MD, FACP, Clinical Associate Professor of Medicine, Stanford University, Division of Infectious Diseases, Santa Clara Valley Medical Center. Dr. Kemper does research for Abbott Laboratories and Merck. The articles originally appeared in the November 2012 issue of Infectious Disease Alert.

Source: Kelso JM, et al. Adverse reactions to vaccines practice parameter update 2012. J Allergy Clin Immunol 2012;130:25-43.

Data continue to lend support for the administration of influenza vaccine to individuals with serious egg allergy. Serious egg allergy occurs in about 1.5% of people, most of whom, as a result, choose not to get influenza vaccination. Influenza vaccine is developed in a chicken egg, and does include minute amounts of egg protein.

Researchers at the Mayo Clinic evaluated 367 individuals, mostly children, with a history of serious egg allergy, who received annual influenza vaccine for 5 years. One-third of participants reported a history of anaphylaxis to egg. During the 5-year project, only 13 (3.5%) developed “allergy-type” side effects from vaccination, none of which were severe, and most of which consisted of mild rash or urticaria within a day of vaccination.

The investigators also examined 26 additional influenza vaccine studies involving a total of more than 4000 egg-allergic people, and found that none of the participants had developed a serious reaction to the injectable vaccine. The investigators stressed that the benefits of influenza vaccination outweigh the potential risks, especially in small children under the age of 5.