Revised CDC Recommendations for Influenza Allows Vaccine for Children with Egg Allergy
The US Centers for Disease Control and Prevention have issued its latest recommendations for the Prevention and Control of Influenza with Vaccines. The Advisory Committee on Immunization Practices provides guidance for the types of vaccine strains to be included in this year’s flu shots as well as recommendations for patients who have egg allergy, once thought to have to avoid receiving the vaccine.
Severely Allergic Patients Should Continue to Avoid Flu Shot
All currently available influenza vaccines are prepared by inoculation of virus into chicken eggs. On most packaging labels and inserts, hypersensitivity to eggs has been listed as a contraindication for receipt of the flu shot. However, per the CDC, several recent studies have documented safe receipt of the influenza vaccine in the case of a mild reaction to egg protein.
According to the report, published in the Morbidity and Mortality Weekly Report (MMWR), the quantity of egg protein (ovalbumin) in the administered vaccine – 1.4 micrograms per milliliter – was tolerated without serious reaction. For those with severe allergy, such as those who experience anaphylaxis upon the ingestion of egg, there is no known safe threshold known at this time. These patients are still advised against receiving the flu shot.
The CDC offers these recommendations for physicians to decide whether a patient who reports an egg allergy should be offered the influenza vaccine:
• Persons who have experienced only hives following exposure to egg should receive influenza vaccine. However, they should only receive the intramuscular or intradermal shot, and not the intranasal mist (which contains live virus). The patient should be monitored for at least 30 minutes afterward for signs of reaction.
• All other patients who report serious reactions to egg protein, such as angioedema, respiratory distress, lightheadedness or recurrent emesis, or those who required epinephrine or other emergency medical intervention, are more likely to have a serious reaction to the flu vaccine.
• All vaccines should be administered in settings in which personnel and equipment for rapid recognition and treatment of anaphylaxis are available.
The report by the CDC continues to advise that all persons aged 6 months and older receive an annual influenza vaccine. The 2011-2012 formulation will provide protection against A/California/7/2009 (H1N1)-like, A/Perth/16/2009 (H3N2)-like, and B/Brisbane/60/2008-like antigens. This is the same formula offered in last year’s flu shot.
Children aged 6 months through 8 years are required two receive 2 doses of influenza vaccine, administered a minimum of 4 weeks apart, during their first season of immunization to optimize immune response. If children received the flu shot last year, only one dose is recommended for this season.
In addition to the intramuscular vaccine, a new Fluzone Intradermal preparation was approved by the FDA in May 2011. This injection is administered via single-dose, prefilled microinjection syringe in the deltoid muscle. It is indicated for persons aged 18 through 64 and contains less antigen than the intramuscular injection. The intranasal administered live attenuated influenza vaccine (LAIV) – FluMist – is also available and indicated for healthy, nonpregnant persons aged 2 through 49 years.
The updated ACIP guidance is based, in part, on findings from recent studies discussed in the Guidelines for the Diagnosis and Management of Food Allergy in the United States: Report of the NIAID-Sponsored Expert Panel.