European Union legislation has established that the maximum permissible concentration of egg protein within a vaccine which is considered safe for individuals with egg-induced anaphylaxis is 2 micrograms/ml. The sub-cutaneous influenza vaccines vary from year to year and an updated list of vaccines that are available with their respective ovalbumin content can be found in the Department of Health Green book. Most vaccines contain between 0.2 – 2 micrograms of ovalbumin per ml and there are no current vaccines which are egg free. Adults with an egg allergy should be offered one of the sub-cutaneous vaccines containing low amounts of the egg protein (generally less than 0.12 micrograms of ovalbumin per ml). This can be offered in any setting. Individuals however who have had severe anaphylaxis to egg requiring intensive care should be referred to an adult allergist for assessment and if appropriate the vaccine should be given in hospital.
Immunocompetent children with an egg allergy will be offered the live-attenuated influenza vaccine (LAIV) via nasal administration. This is the preferred route of delivery in this group and is less likely to cause systemic reactions. The evidence from various studies including the SNIFFLE study undertaken in the UK, indicates that all children with an egg allergy including those with previous anaphylaxis to egg can be safely vaccinated with the LAIV in any setting, including primary care and schools. The only exception are children who have previously experienced anaphylaxis to egg requiring ventilation in an intensive care setting. These children are rare and the data pertaining to the safety of the LAIV in this cohort is lacking. Immunocompromised individuals should not be given live vaccines and this includes those on immunosuppressive treatment such as biologics.