FluMist is the brand name of a nasal spray influenza vaccine. FluMist contains live, weakened influenza viruses intended to trigger protective immunity against disease-causing influenza viruses. The U.S. Food and Drug Administration has approved FluMist for use in nonpregnant, healthy people ages 2 through 49. FluMist warnings advise against use of this vaccine in specific populations and note possible risks and complications of FluMist administration.
Asthma and Wheezing
The prescribing information for FluMist warns that children younger than 2 years of age, children younger than age 5 with a history of wheezing, and people of any age with asthma should not be given the FluMist vaccine. The manufacturer notes an increased risk of wheezing episodes after vaccination with FluMist in these populations.
Weakened Immune Function
The Centers for Disease Control and Prevention (CDC) recommends people with HIV/AIDS or other illnesses or conditions that weaken the immune system should not receive FluMist due to an increased risk of complications. CDC recommends the flu shot for people living with HIV/AIDS. Notably, CDC advises FluMist is safe for people in close contact with others who have a weakened immune system, such as those with HIV/AIDS and people taking immunosuppressive medications.
Pre-existing Medical Conditions
CDC advises that FluMist is appropriate only for healthy people without pre-existing medical conditions such as lung, heart, liver or kidney disease, diabetes and chronic anemia or other blood diseases. People with pre-existing medical conditions have an increased risk of influenza-related complications that may be triggered by FluMist administration.
Pregnancy
Pregnant women should not take FluMist, according to the CDC. The prescribing information for FluMist notes the safety of FluMist in pregnant women has not been studied. CDC recommends the flu shot for pregnant women.
Guillain-Barre Syndrome
Guillain-Barre syndrome is a rare disorder in which the immune system attacks sensory and muscle-controlling nerves, causing loss of sensation and temporary paralysis. The National Institute for Neurological Disorders and Stroke reports that Guillain-Barre syndrome most commonly occurs after a viral illness but may also occur after vaccinations. CDC warns that people who have previously experienced Guillain-Barre syndrome after an influenza immunization should not take FluMist.
Reye's Syndrome
Reye's syndrome is a rare disorder characterized by marked brain swelling and severe liver damage, typically occurring during recovery from a viral illness. Research studies indicate an increased risk of Reye's syndrome associated with aspirin and aspirin-like medicines. Therefore, the prescribing information specifies FluMist should not be administered to children ages 2 through 17 taking aspirin or aspirin-like medications.
Allergic Reaction
FluMist contains trace amounts of eggs, gelatin and the antibiotic gentamicin. CDC and the manufacturer of FluMist warn people with egg allergy, gentamicin allergy or a history of severe allergic reaction to a prior influenza vaccination should not take FluMist.
References
- MedImmune: FluMist Influenza Vaccine Live, Intranasal--Prescribing Information
- MedImmune: FluMist Contraindications, Warnings and Precautions
- Centers for Disease Control and Prevention: Vaccine Information Statement, Live Intranasal Influenza Vaccine 2009
- Centers for Disease Control and Prevention: The Nasal-Spray Flu Vaccine
- National Institute of Neurological Disorders and Stroke: Guillain-Barre Syndrome
