Single-dose influenza vaccination of patients with egg allergy in a multicenter study

To the Editor: Studies have suggested that the ovalbumin content in recent years' influenza vaccines is extremely low1,2 and that most individuals with egg allergy can be safely vaccinated.3,4 Although there are more conservative approaches, the majority of published studies use a 2-step protocol in which 10% of the dose is administered, followed 30 minutes later by the remaining 90%, a strategy used in the pivotal study by James et al5 in 1998 and confirmed in several studies since then.3,6 Some, however, have documented the safety of a single full dose when the vaccine contains a very low amount of ovalbumin.7 Even patients with a history of severe egg allergy have been safely vaccinated by both strategies. The diagnosis of egg allergy was confirmed by an allergist and based on a clinical history consistent with an allergic reaction within 2 hours of the ingestion of egg and evidence of egg-specific IgE by skin or serum testing, or by an egg-specific IgE level or skin prick test (SPT) with >95% predictive value for type I hypersensitivity.9 A full-strength vaccine SPT was performed along with positive and negative controls.