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Live Intranasal Influenza Vaccine: What You Need to Know

1. Why get vaccinated?

Influenza (“flu”) is a contagious disease. It is caused by the influenza virus, which can be spread by coughing, sneezing, or nasal secretions.

Other illnesses can have the same symptoms and are often mistaken for influenza. But only an illness caused by the influenza virus is really influenza.

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Anyone can get influenza, but rates of infection are highest among children. For most people, it lasts only a few days. It can cause:

  • fever
  • sore throat
  • chills
  • fatigue
  • cough
  • headache
  • muscle aches

Some people get much sicker. Influenza can lead to pneumonia and can be dangerous for people with heart or breathing conditions. It can cause high fever, diarrhea, and seizures in children. On average, 226,000 people are hospitalized every year because of influenza and 36,000 die – mostly elderly.

Influenza vaccine can prevent influenza.

2. Live, attenuated influenza vaccine (nasal spray).

There are two types of influenza vaccine:

  1. Live, attenuated influenza vaccine (LAIV) contains live but attenuated (weakened) influenza virus. It is sprayed into the nostrils.
  2. Inactivated influenza vaccine, sometimes called the “flu shot,” is given by injection. Inactivated influenza vaccine is described in a separate Vaccine Information
    Statement.

Influenza viruses are always changing. Because of this, influenza vaccines are updated every year, and an annual vaccination is recommended.

Each year scientists try to match the viruses in the vaccine to those most likely to cause flu that year. When there is a close match the vaccine protects most people from serious influenza-related illness. But even when the there is not a close match, the vaccine provides some protection.

Influenza vaccine will not prevent “influenza-like” illnesses caused by other viruses. It takes up to 2 weeks for protection to develop after the vaccination. Protection lasts up to a year.

LAIV does not contain thimerosal or other preservatives.

3. Who can get LAIV?

LAIV is approved for people from 2 through 49 years of age, who are not pregnant and do not have certain health conditions (see #4, below). Influenza vaccination is
recommended for people who can spread influenza to others at high risk, such as:

  • Household contacts and out-of-home caregivers of children up to 5 years of age, and people 50 and older.
  • Physicians and nurses, and family members or anyone else in close contact with people at risk of serious influenza.

Health care providers may also recommend a yearly influenzavaccination for:

  • People who provide essential community services.
  • People living in dormitories, correctional facilities, or under other crowded conditions, to prevent outbreaks.

Influenza vaccine is also recommended for anyone who wants to reduce the likelihood of becoming ill with influenza or spreading influenza to others.

4. Some people should not get LAIV

LAIV is not licensed for everyone. The following people should get the inactivated vaccine (flu shot) instead:

  • Adults 50 years of age and older or children between 6 months and 2 years of age. (Children younger than 6 months should not get either influenza vaccine.)
  • Children younger than 5 with asthma or one or more episodes of wheezing within the past year.
  • People who have long-term health problems with:
    • heart disease
    • kidney or liver disease
    • lung disease
    • metabolic disease, such as diabetes
    • asthma
    • anemia, and other blood disorders
  • Anyone with certain muscle or nerve disorders (such as seizure disorders or cerebral palsy) that can lead to breathing or swallowing problems.
  • Anyone with a weakened immune system.
  • Children or adolescents on long-term aspirin treatment.
  • Pregnant women.

WebMD Public Information from the CDC

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