Aurora, CO—For years, pharmacists have routinely asked potential flu vaccine recipients if they are allergic to eggs. Now, there is no need for that question, according to updated guidelines from American College of Allergy, Asthma and Immunology (ACAAI).

The issue has been that most influenza vaccines are grown in eggs and contain tiny amounts of egg protein. Multiple studies have shown, however, that the risk to patients with egg allergies is small and not much different for others getting influenza vaccines, notes the article in Annals of Allergy, Asthma and Immunology.

“When someone gets a flu shot, healthcare providers often ask if they are allergic to eggs,” says lead author Matthew Greenhawt, MD, of the University of Colorado Medical School, chair of the ACAAI Food Allergy Committee. “We want healthcare providers and people with egg allergy to know there is no need to ask this question anymore, and no need to take any special precautions. The overwhelming evidence since 2011 has shown that a flu shot poses no greater risk to those with egg allergy than those without.”

The guideline points out that since publication of the 2013 practice-parameter update, additional data have been published regarding the safety of both inactivated influenza vaccine (IIV) and live attenuated influenza vaccine (LAIV) in egg-allergic recipients, adding that two large multicenter, prospective, cohort studies demonstrated the safety of LAIV in egg-allergic individuals.

The new report also points to guidelines from a range of organizations, including the CDC and the American Academy of Pediatrics, that suggest no additional precautions are necessary for vaccinating adults or children with egg allergies.

The CDC, in 2017-2018 influenza guidelines produced with its Advisory Committee on Immunization Practices, states that Americans with egg allergy of any severity can receive any age-appropriate influenza vaccine; however, the guidelines also advise that those who have had reactions with symptoms other than hives receive the vaccine in a medical setting and be supervised by a healthcare professional.

The article points out that prior practice parameters have recommended that egg-allergic patients could safely receive their vaccination at an allergist’s office but that the updated parameter calls for no such special precautions.

“There are hundreds of thousands of hospitalizations, and tens of thousands of deaths in the United States every year because of the flu, most of which could be prevented with a flu shot,” said coauthor John Kelso, MD. “Egg allergy primarily affects young children, who are also particularly vulnerable to the flu. It's very important that we encourage everyone, including children with egg allergy, to get a flu shot.”

The guidelines add that because anaphylaxis can happen with any vaccine at a rate of about one per million, whether or not the recipient has an allergy, those administering immunizations should always have procedures in place to address such events, however rare.
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