FluMist influenza vaccine live intranasal

Medically Reviewed on 4/23/2022

Brand Names: FluMist, FluMist Quadrivalent

Generic Name: influenza nasal vaccine

What is FluMist influenza nasal vaccine, and what is it used for?

FluMist is a nasal vaccine that protects against infection with the influenza virus or the "flu." FluMist contains live influenza virus that has been weakened so that it causes minimal or no symptoms. When FluMist is inhaled, the body responds to the weakened viruses in FluMist by developing antibodies that fight influenza viruses. These antibodies protect against later infections by the naturally-occurring influenza virus.

FluMist is effective only against the strains of influenza virus that are included in it, and the strains of virus change from year to year. FluMist has no effect on the flu once infection has begun. FluMist should be given shortly before the flu season begins to allow time for antibodies to be produced and for protection throughout the entire flu season.

FluMist and FluMist Quadrivalent are similar except for the addition of one additional virus strain to Flumist Quadrivalent. FluMist is a trivalent vaccine because it has three flu virus strains (two type A viruses and one B type) and FluMist Quadrivalent has four virus strains (two A type and two B types).

The FDA approved FluMist in June 2003 and FluMist Quadrivalent in February 2012.


  • Do not administer FluMist to children 5 to 17 years of age who are also receiving aspirin therapy because of the risk of Reye's syndrome, a serious disease of the liver.
  • FluMist should not be administered to individuals with asthma because it may increase wheezing.
  • FluMist should not be given to pregnant women. 
  • The safety of FluMist in breastfeeding women has not been evaluated.

What are the side effects of FluMist?

The most common side effects of FluMist are:

 Other important side effects includes:

Hypersensitivity reactions also have been reported.

What is the dosage for FluMist?

  • Children 2 to 8 years of age who have not previously received FluMist should be given 2 doses of 0.2 ml at least one month apart.
  • Children 2 to 8 years of age, who previously received FluMist and adults 9 to 49 years of age, should be given 1 dose (0.2 ml) of FluMist each season.
  • FluMist is administered by inhaling through the nose while standing or sitting in an upright position. FluMist is not administered by injection.
  • Since FluMist contains viruses that are likely to cause the flu in the upcoming season, FluMist developed for previous seasons will not be effective and should not be used.

Which drugs interact with FluMist?

  • Children 5 to 17 years of age who are receiving aspirin therapy should not be given FluMist because of the association between aspirin, influenza infection, and Reye's syndrome, a serious disease of the liver.
  • Use of FluMist together with antiviral drugs that are active against the influenza virus has not been evaluated. Since there is a potential for antiviral drugs to reduce the effectiveness of FluMist (by preventing infection with the weakened viruses in FluMist), antiviral drugs should not be administered until 2 weeks after FluMist therapy, and FluMist should not be administered until 48 hours after antiviral therapy is discontinued.
  • Administering FluMist with inactivated virus vaccines was not evaluated in FluMist clinical trials, and combining FluMist with other intranasal products has not been evaluated. FluMist did not interfere with, and was not affected by measles, mumps, rubella, or varicella live vaccines.


Which illness is known as a viral upper respiratory tract infection? See Answer

Pregnancy and breastfeeding

  • FluMist should not be given to pregnant women.
  • Use of FluMist during breastfeeding has not been adequately evaluated, and it is not known whether FluMist is excreted in breast milk.

What else should I know about influenza nasal vaccine?

Do I need a prescription for influenza nasal vaccine?
  • Yes
What preparations of influenza nasal vaccine are available?
  • Intranasal Spray: prefilled single use intranasal spray, 0.2 ml
How should I keep influenza nasal vaccine stored?
  • FluMist should be stored refrigerated between 2 C to 8 C (35 F to 46 F).


Influenza vaccine live, intranasal (generic names); FluMist, FluMist Quadrivalent (brand names) is a nasal vaccine prescribed to protect against infection with the influenza virus which causes "flu." FluMist contains live influenza virus that has been weakened, to cause minimal to no flu symptoms. Influenza strains change from year to year, so a new influenza vaccine must be created annually to protect against the new strain of influenza viruses. FluMist is administered shortly before the flu season begins. FluMist contains three flu virus strains (two type A viruses and one type B virus). FluMist quadrivalent has four virus strains (two type A viruses and two type B viruses). FluMist and FluMist Quadrivalent do not prevent 2009 H1N1 (swine flu) viral infection. FluMist is prescribed to prevent influenza viral infections in people between the ages of 2 to 49 years. Side effects, drug interactions, dosage, and pregnancy safety information should be reviewed with your doctor prior to taking FluMist or FluMist Quadrivalent.

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Medically Reviewed on 4/23/2022
FDA Prescribing Information.

FDA. Vaccines, Blood & Biologics. "FluMist Quadrivalent." 08/20/2013.

Vaccines, Blood & Biologics. February 29, 2012 Approval Letter - FluMist & Quadrivalent.