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Questions & Answers
The Nasal-Spray Flu Vaccine (Live Attenuated Influenza Vaccine [LAIV])
How effective is the nasal-spray flu vaccine LAIV (FluMist®)?
In one large study among children aged 15-85 months, the nasal-spray flu vaccine LAIV (FluMist®) reduced the chance of influenza illness by 92% compared with placebo. In a study among adults, the participants were not specifically tested for influenza. However, the study found 19% fewer severe febrile respiratory tract illnesses, 24% fewer respiratory tract illnesses with fever, 23-27% fewer days of illness, 13-28% fewer lost work days, 15-41% fewer health care provider visits, and 43-47% less use of antibiotics compared with placebo.
Who can be vaccinated with the nasal-spray flu vaccine LAIV (FluMist®)?
LAIV (FluMist®) is approved for use in healthy* people 2-49 years of age who are not pregnant.
Who should not be vaccinated with the nasal-spray flu vaccine LAIV (FluMist®)?
- People less than 2 years of age
- People 50 years of age and over
- People with a medical condition that places them at high risk for complications from influenza, including those with chronic heart or lung disease, such as asthma or reactive airways disease; people with medical conditions such as diabetes or kidney failure; or people with illnesses that weaken the immune system, or who take medications that can weaken the immune system.
- Children <5 years old with a history of recurrent wheezing
- Children or adolescents receiving aspirin
- People with a history of Guillain-Barré syndrome, a rare disorder of the nervous system
- Pregnant women
- People who have a severe allergy to chicken eggs or who are allergic to any of the nasal spray vaccine components.
Should the nasal-spray flu vaccine LAIV (FluMist®) be given to patients with chronic diseases other than those specifically listed above?
No. The nasal-spray flu vaccine is approved for use only in healthy* people 2-49 years of age who are not pregnant.
Are there any contraindications to giving breastfeeding mothers LAIV (FluMist®)?
Breastfeeding is not a contraindication for FluMist®. See www.cdc.gov/mmwr/preview/mmwrhtml/rr5306a1.htm for a list of contraindications for FluMist®.
Can the nasal-spray flu vaccine LAIV (FluMist®) be given to patients when they are ill?
The nasal-spray flu vaccine LAIV (FluMist®) 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, then delaying of vaccination until the nasal congestion is reduced should be considered.
Can people receiving the nasal-spray flu vaccine LAIV (FluMist®) pass the vaccine viruses to others?
In clinical studies, transmission of vaccine viruses to close contacts has occurred only rarely. The current estimated risk of getting infected with vaccine virus after close contact with a person vaccinated with the nasal-spray flu vaccine is low (0.6%-2.4%). Because the viruses are weakened, infection is unlikely to result in influenza illness symptoms since the vaccine viruses have not been shown to mutate into typical or naturally occurring influenza viruses.
Can contacts of people with weakened immune systems get the nasal-spray flu vaccine LAIV (FluMist®)?
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 LAIV (FluMist®). People who have contact with others with lesser degrees of immunosuppression (for example, people with diabetes, people with asthma taking corticosteroids, or people infected with HIV) can get LAIV (FluMist®).
What side effects are associated with the nasal-spray flu vaccine LAIV (FluMist®)?
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 LAIV (FluMist®) be given?
Yearly flu vaccination should begin in September or as soon as vaccine is available and continue throughout the influenza season, into December, January, and beyond. This is because the timing and duration of influenza seasons vary. While influenza outbreaks can happen as early as October, most of the time influenza activity peaks in January or later.
Children 2 years up to 9 years of age getting a flu vaccine for the first time will need two doses of vaccine the first year they are vaccinated, with the first dose ideally being given in September or as soon as vaccine becomes available. The second dose should be given 28 or more days after the first dose. The first dose "primes" the immune system; the second dose provides immune protection. Children who only get one dose but who need two doses can have reduced or no protection from a single dose of flu vaccine. Two doses are necessary to protect these children. If your child needs the two doses, begin the process early, so that children are protected before influenza starts circulating in your community. Be sure to follow up to get your child a second dose if they need one. It usually takes about two weeks after the second dose for protection to begin.
How often should the nasal-spray flu vaccine LAIV (FluMist®) be given?
One dose of LAIV should be given each year before or during the influenza season. Children ages 2 to 9 years of age who require two doses (those receiving influenza vaccine for the first time, and those vaccinated for the first time during the previous influenza season but who only received one dose in that previous season) should receive the two doses at least 28 or more days apart.
Can people who received inactivated influenza vaccine (the flu shot) last year get the nasal-spray flu vaccine LAIV (FluMist®) this year?
Yes, people who got inactivated influenza vaccine (the flu shot) last year can get the nasal-spray flu vaccine LAIV (FluMist®) this year.
Can the nasal-spray flu vaccine LAIV (FluMist®) be given at the same time as other vaccines?
An inactivated vaccine may be given either at the same time or at any time before or after the nasal-spray flu vaccine. A live vaccine may be given together with the nasal-spray flu vaccine. If the two live vaccines are not given at the same visit, they should be given more than 4 weeks apart.
Can the nasal-spray flu vaccine LAIV (FluMist®) be used together with influenza antiviral medications?
If a person is taking an influenza antiviral drug (including Symmetrel [amantadine] for Parkinson's disease), 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 has received the nasal-spray flu vaccine, an influenza antiviral medication should not be given until 2 weeks after the nasal-spray flu vaccine was administered.
If a child under the age of 9 years is getting influenza vaccine for the first time and requires 2 doses, does the same type of vaccine have to be used for both doses?
No, the first and second doses do not have to match; live or inactivated vaccine can be used for either dose. The doses should be separated by at least one month.
How is the nasal-spray flu vaccine LAIV (FluMist®) stored?
The nasal-spray flu vaccine LAIV (FluMist®) must be stored in a refrigerator at 2-8°C (35-46°F).
What personal protective equipment is recommended for health-care workers who are giving LAIV (FluMist®)?
Personal protective equipment (gloves and masks) are not needed.
Does the nasal-spray flu vaccine LAIV (FluMist®) contain thimerosal?
No, the nasal-spray flu vaccine LAIV (FluMist®) does not contain thimerosal or any other preservative.
Can the nasal spray flu vaccine give you the flu?
Unlike the flu shot, the nasal spray flu vaccine does contain live viruses. However, 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 2-17 years of age have reported experiencing mild reactions after receiving nasal spray flu vaccine, including runny nose, nasal congestion or cough, chills, tiredness/weakness, sore throat and headache. Some adults 18-49 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" indicates persons who do not have an underlying medical condition that predisposes them to influenza complications.
- Page last modified July 17, 2008
- Content Source: Coordinating Center for Infectious Diseases (CCID)
- National Center for Immunization and Respiratory Diseases (NCIRD)
