FluMist Quadrivalent is a nasal spray flu vaccine used to prevent infection against four strains of the influenza virus. FluMist works by exposing you to a small dose of the weakened influenza virus, which helps your body to develop immunity to the disease. FluMist Quadrivalent can be used for people from 2 to 49 years of age.

FluMist Quadrivalent 2023-2024 Formula contains two influenza A subtype viruses (A/H1N1 strain,  A/H3N2 strain) and two influenza B strains (B/Yamagata/16/88 lineages, B/Victoria/2/87 lineages). The vaccine is redeveloped each year to contain specific strains of activated (live) flu virus that are recommended by public health officials for that year.

Influenza (commonly known as "the flu") is a serious disease caused by a virus. Influenza virus can spread from one person to another through small droplets of saliva that are expelled into the air when an infected person coughs or sneezes. The virus can also be passed through contact with objects the infected person has touched, such as a door handle or other surfaces.

This vaccine is made from "live viruses" and may cause you to have mild flu-like symptoms.

FluMist is given as a nasal spray, one spray into each nostril.

Children ages 2 to 8 years old may need a second dose at least 1 month after the first nasal vaccine. Follow your doctor's instructions or the schedule recommended by your local health department.

Since the influenza virus vaccine is redeveloped each year for specific strains of influenza, you should receive a flu vaccine every year.

Usual Dose 9 years to 49 years for Influenza Prophylaxis:
A single dose = One spray (0.1 mL) into each nostril. 

Usual Pediatric Dose (2 to 8 years): for Influenza Prophylaxis:
1 or 2 doses Use Advisory Committee on Immunization Practices annual recommendations to determine the number of doses.
First dose = One spray (0.1 mL) into each nostril.
Second dose (if required) = One spray (0.1 mL) into each nostril at least one month after first dose.

You should not use this nasal spray if you:

• have a severe allergy to eggs or to any inactive ingredient in the vaccine (see Ingredients) 
• you ever had a life-threatening reaction to influenza vaccinations 
• are 2 through 17 years old and take aspirin or medicines containing aspirin. Children or adolescents should not be given aspirin for 4 weeks after getting this nasal spray unless your healthcare provider tells you otherwise. 

Please talk to your healthcare provider if you are not sure if the items listed above apply to you or your child.

Children under 2 years old have an increased risk of wheezing (difficulty with breathing) after getting this vaccination. 

Who may not be able to get FluMist Quadrivalent? 

Tell your healthcare provider if you or your child: 

• are currently wheezing 
• have a history of wheezing if under 5 years old 
• have had Guillain-Barré syndrome 
• have a weakened immune system or live with someone who has a severely weakened immune system 
• have problems with your heart, kidneys, or lungs 
• have diabetes 
• are pregnant or nursing 
• are taking Tamiflu®, Relenza®, amantadine, or rimantadine.

You can still receive a vaccine if you have a minor cold. In the case of a more severe illness with a fever or any type of infection, wait until you get better before receiving this vaccine

 If you or your child cannot take FluMist Quadrivalent, you may still be able to get an influenza shot. Talk to your healthcare provider about this.

Pregnancy

Talk to your doctor if you are pregnant or planning a pregnancy, you may not be able to have the nasal spray. FluMist Quadrivalent is not absorbed systemically following intranasal administration and is not expected to result in exposure to the vaccine to the unborn baby.

Breastfeeding 

Talk to your doctor if you are breastfeeding. FluMist is not absorbed systemically by the mother after being given in the form of a nasal spray, and breastfeeding is not expected to result in the exposure of the child to this vaccine.

Call your doctor if you forget to receive your yearly vaccine in October or November or if your child misses a booster dose.

An overdose of FluMist is unlikely to occur.

Antiviral medicines. Avoid using antiviral flu medications (such as amantadine, oseltamivir, rimantadine, zanamivir, Flumadine, Tamiflu, Relenza) for at least 2 weeks after receiving FluMist,

Immunosuppressed individuals. Avoid close contact for at least 7 days after receiving a nasal flu vaccine, with anyone who has a weak immune system caused by a disease such as cancer or HIV, or by using steroids, chemotherapy, radiation, or other treatments that can weaken the immune system. People with weak immune systems can become ill if they are in close contact with you when you recently received a live vaccine.

Nasal flu vaccine is made from "live viruses" and may cause you to have mild flu-like symptoms. You may have flu-like symptoms at any time during flu season that could be caused by other strains of the influenza virus.

Common FluMist Quadrivalent side effects include:

• fever over 100° F
• chills
• runny or stuffy nose
• sore throat. 

Other possible side effects are:

• low appetite
• muscle pain
• headache
• feeling irritable 
• chills
• feeling tired.

Serious FluMist Quadrivalent side effects 

Get emergency medical help if you have signs of an allergic reaction to this nasal spray: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

You should not receive a booster vaccine if you had a life-threatening allergic reaction after the first shot.

This is not a complete list of side effects, and others may occur. Call your doctor for medical advice about side effects. You may report vaccine side effects to the US Department of Health and Human Services at 1-800-822-7967.

Anyone 2 to 17 years old receiving this nasal spray vaccination should not take aspirin for at least 4 weeks after the vaccine. A possible interaction between the nasal flu vaccine and aspirin can cause a serious or fatal condition called Reye's syndrome.

Before receiving this vaccine, tell your vaccination provider about all other vaccines you have recently received.

Other drugs may interact with influenza virus nasal vaccine, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all other medicines you use.