The nasal-spray flu vaccine (sometimes called LAIV for Live Attenuated Influenza Vaccine) is a new flu vaccine that was licensed in 2003. It is different from the other licensed influenza vaccine (also called the "flu shot") because it contains weakened live influenza viruses instead of killed viruses and is administered by nasal spray instead of injection.
Updated Dec 10, 2003
How does the nasal-spray flu vaccine (LAIV) work?
The nasal-spray flu vaccine contains three different live (but weakened) influenza viruses. When the viruses are sprayed into the nose, they stimulate the body's immune system to develop protective antibodies that will prevent infection by naturally occurring influenza viruses.
Updated Dec 10, 2003
The live viruses in the nasal-spray flu vaccine (LAIV) are attenuated, cold-adapted, and temperature sensitive. What does this mean?
Attenuated means the viruses are weakened and will not cause severe symptoms often associated with influenza illness. Cold-adapted and temperature sensitive mean the viruses can grow in the nose and throat, but not in the lower respiratory tract where the temperature is higher.
Updated Dec 10, 2003
How effective is the nasal-spray flu vaccine (LAIV)?
In one large study among children aged 15-85 months, the nasal-spray flu vaccine (LAIV) 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.
Updated Dec 10, 2003
Who can be vaccinated with the nasal-spray flu vaccine (LAIV)?
LAIV is approved for use in healthy people between the ages of 5 and 49 years.
Updated Dec 10, 2003
Who should not be vaccinated with the nasal-spray flu vaccine (LAIV)?
- People less than 5 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 or adolescents receiving aspirin
- People with a history of Guillain-Barre syndrome, a rare disorder of the nervous system
- Pregnant women
- People with a history of allergy to any of the components of LAIV or to eggs
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 between the ages of 5 and 49 years.
Updated Dec 10, 2003
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%-2.4%). Because the viruses are attenuated and cold-adapted, 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.
Updated Dec 10, 2003
Can contacts of people with weakened immune systems get the nasal-spray flu vaccine (LAIV)?
Use of inactivated influenza vaccine (the flu shot) is preferred for vaccinating household members, health-care workers, and others who have close contact with people who have weakened immune systems because of the theoretical risk that a vaccine virus could be transmitted and cause illness. Otherwise, either inactivated vaccine or the nasal-spray flu vaccine can be used for healthy people between the ages of 5 and 49 years who are in close contact with other people at high risk for flu-related complication (for example, people with heart disease who are not on medications that could weaken the immune system).
Updated Dec 10, 2003
What side effects are associated with the nasal-spray flu vaccine (LAIV)?
In children, side effects can include runny nose, headache, 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.
Updated Dec 10, 2003
