Children with egg allergies may be able to safely get their flu shot in one dose, just like other kids, a new study suggests.
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.
To be safe, children with egg allergies often get their flu shot divided into smaller doses. They might, for instance, get 10 percent of the dose, then if they have no allergic reaction get the remainder of the dose 30 minutes later.
Children with a history of severe allergic reaction to egg could get up to five small doses.
However, today's flu vaccines actually contain "vanishingly small" amounts of egg protein, said Dr. Susan Laubach, the senior researcher on the new study and a physician at Walter Reed Army Medical Center in Washington, D.C.
And studies have been suggesting that flu vaccination is safe for most children with egg allergies.
A study last year in the journal Pediatrics found that of 171 egg-allergic children who received a two-dose flu shot, upwards of 95 percent had no significant reaction. A few had mild symptoms like hives and itchy skin.
The new study, published in the Journal of Allergy & Clinical Immunology, looked at the safety of single-dose vaccination.
Laubach and her colleagues reviewed the records of 152 egg-allergic patients—mostly young children—who had gotten a seasonal flu shot and/or the vaccine against "swine flu" during the 2009-2010 flu season.
All of the patients underwent skin-prick testing to see if they were likely to have an immune reaction to the flu vaccine. Only one child had a positive result on the skin test, while six had unclear findings. So, most of the study group was given a single-dose flu shot.
Overall, Laubach's team found, none of the patients had a serious reaction to the vaccine, whether they got one dose or divided doses. That included the 22 percent of patients with a history of severe reactions to egg.
"The results of this study, combined with others, suggest that most kids with egg allergy can probably receive the flu vaccine safely," Laubach told Reuters Health.
These latest findings also suggest that many kids can be vaccinated, literally, in one shot—which would offer the advantage of having to jab young children only once.
However, more research is needed to confirm that, according to Laubach. She said a clinical trial is now underway comparing two- and single-dose vaccination in egg-allergic kids.
Such clinical trials, Laubach noted, "are our 'gold standard' for proof."
For now, she recommended that parents of children with egg allergies talk with their doctor about flu vaccination.
In general, experts recommend that all children age 6 months or older get an annual flu shot.
Although the flu causes no more than a week or so of misery in most kids, children younger than 5 are at increased risk of flu complications like pneumonia, bronchitis and sinus infections.
There are probably many children with egg allergies who have never gotten the flu shot, Laubach noted. "I hope that will change in the future," she said.
It's estimated that about 1.5 percent of children are allergic to eggs, according to the American College of Allergy, Asthma and Immunology.