Safe administration of the seasonal trivalent influenza vaccine to children with severe egg allergy

Background: Anaphylaxis to egg or severe egg allergy has been considered a contraindication to receiving trivalent seasonal influenza vaccine (TIV). Objective: To evaluate the safety of TIV among severely egg allergic children. Methods: A 2-phase, multicenter study at 7 sites was conducted between October 2010 and March 2012. Inclusion criteria included a history of a severe reaction, including anaphylaxis, to the ingestion of egg and a positive skin test result or evidence of serum specific IgE antibody to egg. Phase 1 consisted of a randomized, prospective, double-blind, placebo controlled trial of TIV administration to egg allergic children, using a 2-step approach; group A received 0.1 mL of influenza vaccine, followed in 30 minutes if no reaction with the remainder of an age-appropriate dose, whereas group B received an injection of normal saline followed in 30 minutes if no reaction with the full 100% of the age-appropriate dose. Phase 2 was a retrospective analysis of single dose vs split-dose administration of TIV in eligible study participants who declined participation in the randomized controlled trial. Results: Thirty-one study participants were prospectively evaluated in the randomized controlled trial (group A, 14; group B, 17); 45.1% had a history of anaphylaxis after egg ingestion. A total of 112 participants were retrospectively evaluated (87 with the single dose and 25 with the split dose); 77.6% of participants had a history of anaphylaxis after egg ingestion. All participants in both phases received TIV without developing an allergic reaction. Conclusion: TIV administration is safe even in children with histories of severe egg allergy. Use of 2-step split dosing appears unnecessary because a single dose was well tolerated.