How Effective Is the Nasal-Spray Flu Vaccine (Live Attenuated Influenza Vaccine [LAIV])?

In one large study among children aged 15 to 85 months, the nasal-spray flu vaccine LAIV reduced the chance of influenza illness by 92 percent compared with placebo. In a study among adults, the participants were not specifically tested for influenza. However, the study found 19 percent fewer severe febrile respiratory tract illnesses, 24 percent fewer respiratory tract illnesses with fever, 23 percent to 27 percent fewer days of illness, 13 percent to 28 percent fewer lost work days, 15 percent to 41 percent fewer health care provider visits, and 43 percent to 47 percent less use of antibiotics compared with placebo.

Who Can Be Vaccinated With the Nasal-Spray Flu Vaccine LAIV?

LAIV is approved for use in healthy* people 2 to 49 years of age† who are not pregnant.

Who Should Not Be Vaccinated With the Nasal-Spray Flu Vaccine LAIV?

• People younger than 2 years of age†

• People 50 years of age and older

• 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 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 to 49 years of age† who are not pregnant.

Are There Any Contraindications to Giving Breastfeeding Mothers LAIV?

Breastfeeding is not a contraindication for LAIV. See www.cdc.gov/mmwr/preview/mmwrhtml/rr5306a1.htm for a list of contraindications.

Can the Nasal-Spray Flu Vaccine LAIV Be Given to Patients When They Are Ill?

The nasal-spray flu vaccine LAIV 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 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 percent to 2.4 percent). 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?

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. 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.

What Side Effects Are Associated With the Nasal-Spray Flu Vaccine LAIV?

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 Be Given?

October or November is the best time to get vaccinated. Children ages 2 to 8 years who have never received influenza vaccine should receive the nasal-spray flu vaccine for the first time in October or earlier because they need a second dose at least one month after the first dose.

How Often Should the Nasal-Spray Flu Vaccine LAIV Be Given?

One dose of LAIV should be given each year before or during the influenza season. Children ages 2 to 8 years† 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 one month apart.

Can People Who Received Inactivated Influenza Vaccine (the Flu Shot) Last Year Get the Nasal-Spray Flu Vaccine LAIV This Year?

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

Can the Nasal-Spray Flu Vaccine LAIV 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 four weeks apart.

Can the Nasal-Spray Flu Vaccine LAIV 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 two 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 Two 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 Stored?

The nasal-spray flu vaccine LAIV must be stored in a refrigerator at 2 degrees to 8 degrees Celsius (35 degrees to 46 degrees Fahrenheit).

What Personal Protective Equipment Is Recommended for Health Care Workers Who Are Giving LAIV?

Personal protective equipment (gloves and masks) are not needed.

Does the Nasal-Spray Flu Vaccine LAIV Contain Thimerosal?

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

What Changes Were Made to the 2007-08 Nasal-Spray Flu Vaccine LAIV Compared to the 2006-07 Vaccine?

On Sept. 19, 2007, the U.S. Food and Drug Administration approved use of the nasal influenza vaccine LAIV for healthy* children ages 2 to 4 years old (24 to 59 months old) without a history of recurrent wheezing, as well as for healthy persons ages 5 to 49 years who are not pregnant. Previously, approval was for healthy persons ages 5 to 49 years who are not pregnant.

The amount of time between the first and second doses of LAIV for children 2 to 8 years who require two doses has been changed to four weeks from six weeks. The number of days between the first and second doses of vaccine is now the same for LAIV as it is for trivalent inactivated influenza vaccine (TIV). Additional changes for LAIV include shipping and storage conditions (refrigerator temperature, not frozen) and a reduced volume of 0.1 mL per nostril compared to the previous 0.25 mL per nostril.

Source: National Center for Immunization and Respiratory Diseases, U.S. Centers for Disease Control and Prevention

Updated: January 17, 2008

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