Recommendations for the administration of influenza vaccine in children allergic to egg.

For the full versions of these articles see bmj.com Egg allergy affects about 2.6% of preschool children by 3 years of age, and influenza immunisation using egg based vaccines has been classified as a " relative contra indication " (prescribe with extra caution) in this patient group. 1 Until now the numbers of children with egg allergy requiring immunisation has been low, but this may change with the potential for a mass immunisation campaign. This article reviews the literature on the safety of flu vaccines and provides guidelines for the administration of these vaccines to children with egg allergy. Although egg-free flu vaccines are expected to be available for this season, the provision of sufficient amounts of this vaccine cannot be guaranteed at the time of writing, and a pragmatic strategy for the safe immunisation of children with egg allergy is required. Sources and selection criteria We identified articles using PubMed and the search terms " influenza " and " egg allergy ". We identified further references within relevant papers. We found two randomised clinical trials, but most evidence comes from small case series. what vaccines are available? This season two varieties of flu vaccine will be available: a pandemic A/H1N1 strain and the normal trivalent seasonal flu vaccine that will contain an A/H1N1 virus but will not protect against the pandemic strain. There is an egg-free flu vaccine for seasonal immunisation, and it is anticipated that there will be one available for the pandemic strain (table 1). These egg-free vaccines are produced using new viral culture techniques in a mammalian cell line. 2 3 Inactivated, split flu virus, split virion, subunit, or surface antigen flu vaccines are grown in hens' eggs and contain residual allergenic egg white proteins. Some but not all of last season's flu vaccines (2008) reported maximum egg protein content above the proposed safety cutoff of 1.2 μg/ml, with levels up to 2 μg/ml. Virosomal vaccines are highly purified, and although still grown in egg cultures, often have much less residual egg protein. 4 what is the evidence for the current contraindications? According to the Department of Health guidance on immunisation in the Green Book and manufacturer's product characteristics, flu immunisation is contraindi-cated by a confirmed anaphylaxis to a previous dose of the vaccine, to any component of the vaccine, or to egg products. 5 Despite the use of anaphylaxis as a severity cutoff , flu …