Fran Lowry

November 07, 2011

November 7, 2011 — Trivalent influenza vaccine (TIV) is safe to use in children with severe egg allergy, and can be given as a single dose, according to research presented here at the American College of Allergy, Asthma & Immunology 2011 Annual Scientific Meeting.

This finding, from the interim results of a 2-year multicenter trial, confirms the recommendation made earlier this year by the Advisory Committee on Immunization Practices (ACIP) and the American Academy of Pediatrics (AAP) — that egg allergy is no longer a contraindication to vaccination with TIV.

Previously, the AAP Red Book considered anaphylaxis to egg or severe egg allergy a contraindication to receiving the vaccine.

"The benefits of flu shots are well established and clearly outweigh the risks for children with egg allergy," lead author Matthew J. Greenhawt, MD, from the University of Michigan in Ann Arbor, said in a statement.

"Children with food allergies are more likely to have asthma, which can increase their chance of respiratory complications from the flu. Expanding the population of children who receive flu shots will play an important role in decreasing influenza associated with hospitalization and in promoting the overall health of our children," he explained.

Dr. Greenhawt and his coinvestigators sought to evaluate the safety of TIV in children in this prospective double-blind placebo-controlled trial.

Using a 2-step approach, the group randomized 28 children who were contraindicated for TIV according to previous AAP Red Book criteria to receive either a 10%/90% split dose of TIV (n = 13), or to receive normal saline plus 100% TIV (n = 15) to mimic the split dose.

In these 28 children, the mean egg skin test wheal was 7.7 mm, mean egg white ImmunoCAP was 23.1 kuA/L, mean ovalbumin ImmunoCAP was 20.4 kuA/L, and mean ovomucoid ImmunoCAP was 18.1 kuA/L.

There were no differences in these values between the 2 groups, Dr. Greenhawt reported.

In addition, they investigators retrospectively analyzed 32 children with severe egg allergy who were vaccinated by their primary care physician despite the contraindication, for comparison.

This retrospective group consisted of 13 children who received TIV as a split dose as a safety precaution and 19 who received it as a single dose. The mean egg white ImmunoCAP was 18.2 kuA/L, and there was no difference between children who received a single or a 2-step split dose of TIV.

None of the children developed an allergic reaction.

"Use of 2-step split dosing appears unnecessary, as a single dose was well tolerated by those who received this either in an allergy clinic or in the primary care setting," Dr. Greenhawt concluded.

Dr. Todd Mahr

Todd A. Mahr, MD, director of pediatric allergy/immunology at Gundersen Lutheran Medical Center in La Crosse, Wisconsin, and clinical professor of pediatrics at the University of Wisconsin Medical School in Madison, was comoderator of the session. He told Medscape Medical News that "the nice thing about this paper is that it reaffirms the ACIP and the AAP recommendations that have come out for administration of TIV in egg-allergic patients. This paper was actually submitted before [those recommendations] came out. It is nice to have it at our meeting to reconfirm the new recommendations."

"What ACIP and AAP say now is that if the patient can eat egg cooked in things, the general practitioner can just go ahead and give TIV and watch the patient for 30 minutes afterwards," said Dr. Mahr, who was not part of the current study.

Patients with a history of anaphylactic reaction to egg should be sent to a specialist for vaccination. "That specialist can decide what to do. One option is to do a 2-step dosing; another is to give it in 1 dose and be prepared to handle anaphylaxis," Dr. Mahr said.

Dr. Greenhawt reports financial relationships with Phadia, Sunovion, and Nutricia. Dr. Mahr reports financial relationships with ISTA, Alcon, AstraZeneca, Genentech, GlaxoSmithKline, Merck, and Novartis.

American College of Allergy, Asthma & Immunology (ACAAI) 2011 Annual Scientific Meeting: Abstract 2. Presented November 6, 2011.


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