The influenza vaccine is indicated for active immunization against influenza type A and influenza type B viruses that trigger acute respiratory disease. There are 3 main forms of the influenza vaccine: the trivalent inactivated vaccine, the quadrivalent inactivated vaccine, and the live attenuated influenza vaccine. Influenza vaccines available for use in the United States include Afluria (CSL Limited), Agriflu (Novartis), FluLaval (ID Biomedical Corporation of Quebec), Fluarix (GlaxoSmithKline), Flublok (Protein Sciences Corporation), Flucelvax (Novartis), Fluvirin (Novartis), Fluzone (Sanofi Pasteur), and FluMist (MedImmune, LLC). ACIP guidelines recommend routine annual influenza vaccination of all persons aged 6 months or older.
14 Children with chronic underlying medical conditions including diabetes mellitus, asthma (does not have to be uncontrolled) or other chronic disorders of the pulmonary or cardiovascular systems, renal dysfunction, or hemoglobinopathies should not be vaccinated with the live attenuated influenza vaccine.
15 Also, any adolescent female who is pregnant should not receive the live attenuated influenza vaccine.
15 Adolescents through age 17 years who are receiving aspirin or other salicylates should not receive the live attenuated influenza vaccine because of the potential for Reye syndrome.
16 In the United States, the live attenuated vaccine is only available in the intranasal form.
In children aged 6 to 17 years, the most common systemic adverse events after influenza vaccination were fatigue, muscle ache, headache, arthralgia, and gastrointestinal symptoms. According to our VAERS search results, from January 2000 to January 2013, a total of 63,882 adverse events related to the influenza vaccine were reported to the VAERS, with 8050 events in children aged 6 to 17 years. Less than 1% of the reported events were considered life-threatening. In 1976, the swine influenza vaccine was associated with an increased frequency of GBS, but the risk was lower among persons younger than 25 years. Subsequent studies have not demonstrated an increase in GBS of the same magnitude.
17 However, individuals who developed GBS within 6 weeks of receiving a prior influenza vaccination may have an increased risk of GBS after subsequent vaccination with the influenza vaccine. In those circumstances, the physician must consider the potential risks and benefits of administering the influenza vaccine. Certain multi-dose vial preparations of the inactivated influenza vaccine contain thimerosal, a mercury-containing antibacterial compound used to reduce the likelihood of bacterial growth. Evidence to date shows no increased risks from exposures to thimerosal-containing vaccines.
15 The tip caps of prefilled syringes of the influenza vaccine may contain natural rubber latex, which can lead to allergic reactions in individuals who are sensitive to latex.
18
Patients with egg allergy should receive influenza vaccinations because the benefits outweigh the risks of vaccinating in this population. Persons with a history of suspected egg allergy should be evaluated by an allergist to further clarify the egg allergy, but such an evaluation should not delay the administration of the influenza vaccination. Patients with egg allergy should receive influenza vaccines in a setting where clinicians are experienced in recognizing and treating anaphylaxis and should be observed for 30 minutes after vaccination. Patients with egg allergy and with a history of only hives after egg ingestion can receive the influenza vaccine in a primary care provider's office, provided the appropriate observation and equipment are available. Those with a history of a more severe reaction (eg, anaphylaxis) after egg ingestion should receive their vaccine in an allergist's office (
Table). All influenza vaccines available in the United States contain low amounts of ovalbumin, including the intranasally administered form. The injectable vaccination is the preferred form of influenza vaccination for patients with egg allergy. For patients with a history of an allergic reaction to the influenza vaccine itself, referral to an allergist for further evaluation, including skin testing with the vaccine and vaccine ingredients, is appropriate.
19