Live Attenuated Influenza Vaccine [LAIV] (The Nasal Spray Flu Vaccine)

Overview

What flu viruses does the nasal spray vaccine protect against?

All nasal spray influenza (flu) vaccines for the 2024-2025 season are trivalent, meaning they are designed to protect against three influenza viruses: an influenza A(H1N1) virus, an influenza A(H3N2) virus and one influenza B virus.

Who can be vaccinated with the nasal spray flu vaccine?

The nasal spray flu vaccine is approved for use in healthy non-pregnant people, ages 2 through 49 years old. People who are pregnant and people with certain medical conditions should not get the nasal spray flu vaccine.

Can nasal spray vaccine be self-administered?

On September 20, 2024, The Food and Drug Administration (FDA) approved the nasal spray flu vaccine, FluMist, for self or caregiver administration. The option for self or caregiver administration is not expected to be available until next flu season (2025-2026).

Who should not get the nasal spray flu vaccine?

Some people should not get the nasal spray flu vaccine:

• Children younger than 2 years old.
• Adults 50 years and older.
• People with a history of severe allergic reaction to any ingredient of the vaccine (except for egg protein) or to a previous dose of any flu vaccine.
• Children 2 through 17 years old who are receiving aspirin- or salicylate-containing medications.
• Children 2 through 4 years old who have asthma or who have had a history of wheezing in the past 12 months.
• People with weakened immune systems (immunosuppression) from any cause.
• People who care for severely immunocompromised persons who require a protected environment (or otherwise avoid contact with those persons for 7 days after getting the nasal spray vaccine).
• People without a spleen, or with a non-functioning spleen.
• Pregnant people.
• People with an active leak between the cerebrospinal fluid and the mouth, nose, ear, or other place within the skull.
• People with cochlear implants.
• People who have taken flu antiviral drugs within a certain amount of time (within the past 48 hours for oseltamivir and zanamivir, the past 5 days for peramivir, and the past 17 days for baloxavir).

In addition, the following medical conditions are precautions to the use of the nasal spray flu vaccine:

• Asthma in people 5 years and older.
• Other underlying medical conditions that can put people at higher risk of serious flu complications. These include conditions such as lung disease, heart disease (except isolated hypertension), kidney or liver disorders, neurologic/neuromuscular, or metabolic disorders (like diabetes).
• Moderate or severe acute illness with or without fever.
• Guillain-Barré Syndrome within 6 weeks following a previous dose of flu vaccine.

How effective is the nasal spray seasonal flu vaccine?

Flu vaccine effectiveness (VE) can vary from year to year, among different age and risk groups, by vaccine type, and even by virus type and subtype. Prior to the 2009 flu pandemic, the nasal spray vaccine was found to be effective against different flu viruses. After the 2009 pandemic, several U.S. studies among 2 through 17-year-olds found that the nasal spray vaccine was as effective against influenza B viruses and influenza A(H3N2) viruses as inactivated influenza vaccines but was less effective than inactivated flu vaccines against the 2009 pandemic H1N1 viruses. These data led ACIP and CDC to recommend against use of the nasal spray vaccine for the 2016-2017 and 2017-2018 seasons.

Since the 2017-2018 season, the manufacturer of nasal spray vaccine has used new influenza A(H1N1) vaccine virus ingredients in production. Because of limited use, there have been no effectiveness estimates in the United States since LAIV was recommended again in the 2018-2019 influenza season. Data from other countries have demonstrated protection from LAIV to be similar to that of standard-dose, egg-based inactivated flu vaccine in children.

Can I get the nasal spray flu vaccine at the same time as other vaccines?

Yes, nasal spray flu vaccine can be given at the same time as other vaccines (live or non-live). If nasal spray flu vaccine is not given at the same time as another live vaccine, they should be spaced at least four weeks apart. There is no recommended spacing period between nasal spray flu vaccine and non-live vaccines.

Should the nasal spray flu vaccine be given to patients with chronic diseases?

Nasal spray flu vaccine is not recommended for use in people with some chronic health conditions because the safety and effectiveness of this vaccine in people with those conditions has not been established.

Prevention and Control of Seasonal Influenza with Vaccines: Recommendations of the Advisory Committee on Immunization Practices has a list of contraindications and precautions for the nasal spray vaccine.

Should pregnant and postpartum people avoid contact with people who were recently vaccinated with the nasal spray vaccine?

Pregnant and postpartum people do not need to avoid contact with people who recently got the nasal spray flu vaccine. However, the nasal spray flu vaccine should not be given to people who are pregnant. People who have recently had a baby can get a flu shot or the nasal spray flu vaccine.

Are there any contraindications to giving breastfeeding people the nasal spray vaccine?

Breastfeeding is not a contraindication for the nasal spray vaccine. Breastfeeding people younger than 50 years can get the nasal spray flu vaccine as long as they do not have a contraindication to getting that vaccine. Prevention and Control of Seasonal Influenza with Vaccines: Recommendations of the Advisory Committee on Immunization Practices has a list of contraindications and precautions for the nasal spray vaccine.

Can the nasal spray flu vaccine be given to patients when they are ill?

The nasal spray flu vaccine can be given to people with mild illnesses (e.g., diarrhea or mild upper respiratory tract infection with or without fever). However, nasal congestion might limit delivery of the vaccine to the nasal lining, and so delaying vaccination until the nasal congestion is reduced or using an age-appropriate injectable vaccine instead should be considered. People with moderate or severe illness, with or without fever, should generally wait to be vaccinated until they have recovered. Your health care provider can provide advice about when to get vaccinated if you are feeling ill.

Can nasal spray flu vaccine give me flu?

Flu vaccines do not cause flu illness. The nasal spray flu vaccine contains weakened (attenuated) viruses, so that they will not cause flu illness. The weakened viruses are cold-adapted, which means they are designed to only multiply at the cooler temperatures found within the nose, and not the lungs or other areas where warmer temperatures exist.

What are the side effects that could occur with the nasal spray flu vaccine?

In children, side effects from the nasal spray may include:

• Runny nose.
• Wheezing.
• Headache.
• Vomiting.
• Muscle aches.
• Fever (low grade).
• Sore throat (in older children).

In adults, side effects from the nasal spray vaccine may include:

• Runny nose.
• Headache.
• Cough.

If these problems occur, they begin soon after vaccination and usually are mild and short-lived. People sometimes faint after medical procedures, including vaccination. Tell your provider if you feel dizzy or have vision changes or ringing in the ears. Rarely, people can experience a severe allergic reaction after a flu vaccine (or any vaccine); there are about 1-2 cases of severe allergic reactions per million flu vaccine doses administered and these reactions can be treated with medication. People who think that they have been injured by a flu vaccine can file a report with the Vaccine Adverse Event Reporting System (VAERS).

Vaccine Information Statements (VIS)

Flu VISs are no longer updated every year. The edition dated 8/16/2021 should be used for the current flu season. Several formats including PDF are available.