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Influenza virus vaccine (nasal)

Generic name: influenza virus vaccine (nasal) [in-floor-ENZ-a-VYE-rus-VAK-seen]
Brand names include: flumist Quadrivalent 2023-2024 flumist flumist 2010, 2011, flumist 2011, 2012, flumist 2012, 2013… Show all the 14 brands
Dosage form: nasal spray (quadrivalent)
Drug class: viral vaccines

What is the Influenza virus vaccine (nasal)?

Influenza (also known as "the flu") is a contagious illness caused by a viral infection that can be spread through air or surfaces. The flu symptoms include fever and chills. They can also cause aches, nausea, diarrhea, vomiting, and a sore throat. The flu may also lead to ear infections or bronchitis. It can even cause serious complications like pneumonitis.

Influenza is responsible for thousands of deaths and hospitalisations each year. Children, pregnant women, elderly adults, people with weak immune systems, and those with health problems like diabetes or heart disease are at greatest risk.

Influenza virus Nasal vaccination (nasal influenza vaccine) can be used by people aged 2 to 49 to prevent infections due to the influenza virus. This vaccine will help your body build immunity against the virus, but it won't treat an infection that you already have.Each year, the influenza virus vaccine is updated to include strains of flu viruses that have been recommended by health officials.

Nasal flu virus vaccines are made with "live viruses." Influenza virus vaccination is also available in the form of an injection (flu shot), which is a "killed-virus" vaccine. The nasal form is the only one covered in this medication guide.As with any vaccine, the nasal flu vaccine does not protect everyone from infection.

Side effects of Influenza virus vaccine (nasal)

Seek immediate medical attention if you experience any of these symptoms: difficulty breathing, swelling in your face, lips, tongue or throat.If you experienced a severe allergic reaction to the first dose, then a booster shot is not recommended.

Keep track of all side effects. You will need to inform the vaccine provider of any side effects you experienced from the previous nasal flu shot if you are receiving a new one.The nasal flu vaccine contains "live viruses," which may cause mild flu-like symptoms. Flu-like symptoms can occur at any time of the year and could be caused by different strains of influenza viruses.

If the person receiving this vaccine is wheezing or has trouble breathing, call a doctor immediately or seek medical attention.

Side effects that are common include:

  • Fever over 100 degrees F;
  • Chills;
  • Runny or stuffy nasal
  • Sore throat and cough
  • Loss of appetite
  • Muscle pain;
  • Headache
  • Feeling tired or irritable.

There may be other side effects. For medical advice on side effects, call your doctor. Report the side effects of vaccines to the US Department of Health and Human Services by calling 1-800-822-7967.


The vaccine contains "live viruses", which may cause mild symptoms of flu.

Take this medication only if you have been prescribed it.

This vaccine is not recommended if:

  • A history of severe allergy to any influenza vaccine;
  • If you have taken aspirin in the past and are between 2 and 17 years of age,

The nasal flu vaccine is not recommended for children under 2 years of age or adults over 49 years of age.

If you've used:

  • In the last 48 hours, you may have taken oseltamivir or zanamivir.
  • Rapivab or peramivir in the last 5 days
  • In the last 17 days, baloxavir (Xofluza)

If you have certain medical conditions, this vaccine may not be available to you. You should tell the vaccination provider:

  • Asthma or wheezing;
  • A history of wheezing in children younger than five years;
  • A history of Guillain-Barre syndrome within six weeks after receiving the flu vaccine
  • A weak immune system;
  • Heart problems
  • Kidney disease

If you are unable to receive a nasal influenza vaccine due to a medical condition, you may be able to get an injectable influenza vaccine (flu shot) instead.If you are suffering from a minor cold, it is possible to receive a vaccination. Wait until you are better if you have a severe illness, such as a fever or infection.Inform your vaccine provider if you are pregnant or nursing.

The nasal influenza vaccine is not recommended for pregnant women. The Centres for Disease Control and Prevention, however, recommend that pregnant women get a flu shot in any trimester to protect them and their babies against the flu.

How to take Influenza virus vaccine (nasal)?

This vaccine is administered as a nasal spray into each nostril.A second nasal vaccination may be required for children aged 2–8 years, at least one month after their first dose.

Influenza virus vaccines are usually administered in November or October. You can follow the instructions of your doctor or those recommended by your local department of health.You should get a flu shot every year, as the influenza virus vaccines are redeveloped for each strain of influenza.

Details on dosage

Usual Adult Dose for Influenza Prophylaxis:

After 49 years of age:
1 dose (0.2 ml), intranasally, once per influenza season; administer 0.1 ml per nostril.
The CDC recommends against using this vaccine during the flu season of 2016–2017.

Usual Geriatric Dose for Influenza Prophylaxis:

Over 50s are not recommended.

Usual Paediatric Dose for Influenza Prophylaxis:

From 2 to 8 years:
1 or 2 doses (0.2 ml), intranasally, per influenza season: administer 0.1 ml per nostril.
If using two doses, give them at least one month apart.
Use the annual recommendations of the Advisory Committee on Immunization Practices to determine doses.
Age 9 and older
1 dose (0.2 ml), intranasally, once per influenza season; administer 0.1 ml per nostril.
The CDC recommends against using this vaccine during the flu season of 2016–2017.

What happens if I miss the dose?

If you have forgotten to get your annual nasal flu shot in November or October, or if your children missed a booster shot, call your doctor.

What happens if I overdose?

It is very unlikely that this vaccine will cause an overdose.

What should be avoided?

Avoid antiviral flu medication for at least two weeks following the vaccination (such as amantadine, oseltamivir, rimantadine, zanamivir, flumadine, Tamiflu, and Relenza).

Avoid close contact for at least seven days after receiving the nasal flu vaccine with anyone who is suffering from a weakened immune system due to a disease like cancer, HIV, or a treatment such as steroids, chemotherapy, radiotherapy, or any other treatments that can weaken your immune system. If you have recently received a vaccine that contains a live virus, people with weak immune systems may become sick if you are in contact with them.

Interaction with other drug

If you are between the ages of 2 and 17, do not take aspirin until at least four weeks after receiving a nasal influenza vaccine. This could cause a fatal or serious condition known as Reye syndrome.

Tell your provider of vaccinations about any other vaccines that you may have received recently before receiving this vaccine.The influenza virus nasal vaccination may be affected by other drugs, such as prescription and over-the-counter medicines, vitamins, and herbal products. Inform your doctor of all the other medications you take.