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

Questions & Answers

Note: On February 26, 2015, the Advisory Committee on Immunization Practices (ACIP) voted on its annual influenza vaccine recommendations. For 2015-2016, ACIP recommends annual influenza vaccination for everyone 6 months and older with either LAIV or IIV, with no preference expressed for either vaccine when either one is otherwise appropriate. More information on this vote is available at the CDC Newsroom. The LAIV content on this web page will be updated after the 2015-2016 recommendations are approved by the CDC Director and published in the MMWR.

What flu viruses does the nasal spray vaccine protect against?

All nasal spray flu vaccines for the 2014-2015 season will provide protection against four flu viruses: an influenza A (H1N1) virus, an influenza A (H3N2) virus and two influenza B viruses.

Are any of the available flu vaccines recommended over the others?

CDC has not expressed a preference for which flu vaccine people should get this season except for one: Starting in 2014-2015, CDC recommends use of the nasal spray vaccine for healthy* children 2 years through 8 years of age when it is immediately available and if the child has no contraindications or precautions to that vaccine. If the nasal spray vaccine is not immediately available and the flu shot is, vaccination should not be delayed and a flu shot should be given. For more information about the new CDC recommendation, see Nasal Spray Flu Vaccine in Children 2 Years through 8 Years Old or the 2014-2015 MMWR Influenza Vaccine Recommendations.

While there will be more than one vaccine option for many people to choose from, including high-dose vaccine, intradermal vaccine and the regular flu shot, the only preferential recommendation is for the nasal spray vaccine in healthy* children 2 years through 8 years of age. The most important thing is for all people 6 months and older to get a flu vaccine every year. If you have questions about which vaccine is best for you, talk to your doctor or other health care professional.

(*“Healthy” in this instance refers to children 2 years through 8 years old who do not have an underlying medical condition that predisposes them to influenza complications.)

Who can be vaccinated with the nasal spray flu vaccine?

The nasal spray is approved for use in people 2 through 49 years of age.

Who should not be vaccinated with the nasal spray flu vaccine?

  • Children younger than 2 years
  • Adults 50 years and older
  • People with a history of severe allergic reaction to any component of the vaccine or to a previous dose of any influenza vaccine
  • People who are allergic to eggs
  • Children or adolescents (2 years through 17 years of age) on long-term aspirin treatment.
  • Pregnant women
  • People with weakened immune systems (immunosuppression)
  • Children 2 years through 4 years who have asthma or who have had a history of wheezing in the past 12 months.
  • People who have taken influenza antiviral drugs within the previous 48 hours.
  • People who care for severely immunocompromised persons who require a protective environment (or otherwise avoid contact with those persons for 7 days after getting the nasal spray vaccine).

There are also other “warnings and precautions” for the nasal spray flu vaccine. These include:

  • People of any age with asthma might be at increased risk for wheezing after getting the nasal spray vaccine.
  • The safety of the nasal spray vaccine has not been established in people with underlying medical conditions that place them at high risk of serious flu complications. This includes children and adults who have lung disease, heart disease (except isolated hypertension), kidney disease (like diabetes), kidney or liver disorders, neurologic/neuromuscular, or metabolic disorders. See “People at High Risk of Developing Flu–Related Complications.” Moderate or severe acute illness with or without fever is a general precaution for vaccination.
  • GBS within 6 weeks following a previous dose of influenza vaccine is considered a precaution for use of all influenza vaccines.

How effective is the nasal spray seasonal flu vaccine?

Influenza vaccine effectiveness (VE) can vary from year to year, among different age and risk groups and by vaccine type. While the flu shot and the nasal spray vaccine both protect against the flu, there is evidence that the nasal spray flu vaccine may work better in younger children than a regular flu shot. CDC now recommends the nasal spray vaccine for healthy* children 2 years through 8 years when it is immediately available. For more information about vaccine effectiveness, visit How Well Does the Seasonal Flu Vaccine Work? For information specific to this season, visit About the Current Flu Season.

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

There is a precaution against giving the nasal spray flu vaccine to people with certain chronic health conditions because the safety of this vaccine in people with those conditions has not been established.

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

Pregnant and postpartum women do not need to avoid contact with persons recently vaccinated with the nasal spray flu vaccine. However, the nasal spray flu vaccine should not be given to women who are pregnant. Postpartum women can receive the flu shot or the nasal spray flu vaccine.

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

Breastfeeding is not a contraindication for the nasal spray vaccine. Breastfeeding mothers younger than 50 years can get the nasal spray flu vaccine as long as they don’t have any contraindication to getting that vaccine. See Prevention and Control of Seasonal Influenza with Vaccines: Recommendations of the Advisory Committee on Immunization Practices (ACIP) – United States, 2014-2015 Influenza Season - August 15, 2014 for a list of contraindications and warnings 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 minor illnesses (e.g., diarrhea or mild upper respiratory tract infection with or without fever). However, if nasal congestion is present that might limit delivery of the vaccine to the nasal lining. Delaying vaccination with that vaccine until the nasal congestion is reduced should be considered.

Can people who have gotten the nasal spray flu vaccine spread the vaccine viruses to others?

Yes, it is possible, but it is very rare. Data indicate that both children and adults vaccinated with nasal spray flu vaccine can shed vaccine viruses after vaccination, although in lower amounts than typically occurs during shedding of wild-type influenza viruses. Rarely, shed vaccine viruses can be transmitted from vaccine recipients to unvaccinated persons. However, serious illnesses have not been reported among unvaccinated persons who have been infected inadvertently with vaccine viruses.

Can contacts of people with weakened immune systems get the nasal spray flu vaccine?

People who are in contact with others with severely weakened immune systems when they are being cared for in a protective environment (for example, people with hematopoietic stem cell transplants), should not get the nasal spray vaccine, or they should avoid contact with those persons for 7 days following receipt of the nasal spray vaccine. People who have contact with people with weakened (but not severely weakened) immune systems due to underlying illness (e.g. diabetes, asthma, and heart disease, can get the nasal spray vaccine.

What side effects are associated with the nasal spray flu vaccine?

In children, side effects can include runny nose, headache, wheezing, vomiting, muscle aches, and fever. In adults, side effects can include runny nose, headache, sore throat, and cough. Fever is not a common side effect in adults receiving the nasal spray flu vaccine.

When should the nasal spray flu vaccine be given?

Flu vaccination should begin soon after vaccine is available, ideally by October. However, as long as flu viruses are circulating, it’s not too late to get vaccinated, even in January or later. While seasonal influenza outbreaks can happen as early as October, most of the time influenza activity peaks in January or later.

How often should the nasal spray flu vaccine be given?

One dose of the nasal spray flu vaccine (or the flu shot) should be given during each influenza season. Some children 6 months through 8 years of age require two doses of influenza vaccine and should receive the two doses at least 28 or more days apart. Your child’s health care professional can tell you whether two doses are recommended for your child.

Can people who got an inactivated influenza vaccine (flu shot) last year get the nasal spray flu vaccine this year?

Yes, people who got inactivated influenza vaccine (the flu shot) last year can get the nasal spray flu vaccine this year.

Can the nasal spray flu vaccine be given while taking influenza antiviral medications?

No. If a person is taking an influenza antiviral drug (including Tamiflu® or Relenza®), then the nasal spray flu vaccine should not be given until 48 hours after the last dose of the influenza antiviral medication was given. If a person takes antiviral drugs within two weeks of getting the nasal spray flu vaccine, that person should get revaccinated, because the antiviral drugs may prevent the vaccine from working. The flu shot can be given while taking influenza antiviral drugs since the flu shot (given with a needle) does not contain live virus.

Are there special vaccination instructions for children?

While the flu shot and the nasal spray vaccine both protect against the flu, there is evidence that the nasal spray vaccine may work better in younger children than a regular flu shot. CDC now recommends the nasal spray flu vaccine for healthy* children 2 years through 8 years when it is available. (Children 6 months to 2 years of age should only receive the flu shot (TIV)).

Also, some children 6 months through 8 years of age will need two doses of influenza vaccine. Children in this age group who are getting vaccinated for the first time will need two doses. Some children who have received influenza vaccine previously also will need two doses. Your child’s health care professional can tell you whether two doses are recommended for your child.

Does the nasal spray flu vaccine contain thimerosal?

No, the nasal spray flu vaccine does not contain thimerosal or any other preservative.

Can the nasal spray flu vaccine give you the flu?

No. While the nasal spray flu vaccine does contain live viruses (unlike the flu shot), the viruses are attenuated (weakened) and cannot cause flu illness. The weakened viruses are cold-adapted, which means they are designed to only cause infection at the cooler temperatures found within the nose. The viruses cannot infect the lungs or other areas where warmer temperatures exist. Some children and young adults 2 years through 17 years of age have reported experiencing mild reactions after getting the nasal spray flu vaccine, including runny nose, nasal congestion or cough, chills, tiredness/weakness, sore throat and headache. Some adults 18 years through 49 years of age have reported runny nose or nasal congestion, cough, chills, tiredness/weakness, sore throat and headache. These side effects are mild and short-lasting, especially when compared to symptoms of influenza infection.

(*“Healthy” in this instance refers to children 2 years through 8 years old who do not have an underlying medical condition that predisposes them to influenza complications.)

Questions and Answers about the nasal spray vaccine in Spanish

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