Administration of the Adjuvanted Ph1n1 Vaccine in Egg-Allergic Children at High Risk for Influenza A/H1N1 Disease (Quantitative Research) (Report‪)‬

Influenza A/H1N1 usually causes mild disease in otherwise healthy children; however, more serious cases, and even death, have been reported in children and in those with pre-existing medical conditions. (1,2) Given the potential serious nature of this illness, administration of the newly developed adjuvanted pH1N1 vaccine (Arepanrix[TM] H1N1) could be beneficial and the vaccine has been recommended for children; particularly those less than 5 years of age or with chronic underlying disease. (3) Similar to the seasonal influenza vaccine, the adjuvanted pH1N1 vaccine contains residual allergenic egg white proteins. Egg allergy is one of the most common food allergies in children (4) and allergic reactions have been reported in egg-allergic patients treated with the seasonal influenza vaccine. (5,6) However, reports have also been published on the safe vaccination of such patients. (7-9) In the setting of high-risk egg allergy, as defined by the Canadian Society of Allergy and Clinical Immunology (CSACI), it is suggested that egg-allergic patients be vaccinated with a physician present and in a location where access to emergency treatment is available. (10,11) Given the potential risk of allergic reaction in such patients, many parents and practitioners are reluctant to vaccinate. Therefore, egg-allergic patients, including those with chronic underlying disease at risk for serious Influenza A/H1N1 illness, fail to benefit from immunization.