With flu season approaching, a Canadian study offers more reassurance that children with egg allergies can be safely vaccinated against the virus.
Because the flu vaccine is grown in chicken eggs, there have traditionally been concerns about the safety of flu shots for people with egg allergies, most of whom are young children. But today's vaccine has only tiny traces of egg protein, and studies have been showing that children with egg allergies can be vaccinated without any serious reaction.
The researchers, whose findings appeared in The Journal of Allergy and Clinical Immunology, followed 367 egg-allergic people, mostly children, who got the flu shot over five years. Almost one-third of them had a history of anaphylaxis after eating eggs – that is, serious allergy symptoms such as trouble breathing or a drop in blood pressure.
However, none of the patients had a serious reaction to the flu vaccine, and only 13 of the 367 had mild "allergy-like" symptoms, such as itchy skin or hives, within a day of being vaccinated.
"The risk of anaphylaxis appears sufficiently low for patients with egg allergy to be vaccinated like all other individuals, without requiring administration by an allergist," wrote lead researcher Anne Des Roches, of Hôpital Sainte-Justine in Montreal, and her colleagues.
They also reviewed 26 past studies that involved close to 4,000 egg-allergic people who got the flu shot. None of those patients developed a serious allergic reaction.
In general, experts recommend that all children six months or older get an annual flu shot. Although the flu causes no more than a week or so of misery in most children, children younger than 5 are at increased risk of complications such as pneumonia, bronchitis and sinus infections.
About 1.5 per cent of children have an egg allergy, according to the American College of Allergy, Asthma and Immunology. It is thought that many of them have never gotten the flu shot over worries about an allergic reaction.
"I think parents of children with egg allergy should be reassured about the safety of the influenza vaccine for their child, and understand that the benefits are likely to outweigh any risks," Lynda Schneider, director of the allergy program at Boston Children's Hospital, said in an e-mail.