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Vaccines Health Center

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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.

Recommended Related to Adult Vaccines

MMR Vaccine for Adults

The MMR vaccine protects against measles, mumps, and rubella (German measles). Many children in the U.S. are immunized as infants and toddlers, but that doesn't guarantee lifetime protection. And not everyone gets vaccinated as a child. Many adults move to the U.S. from countries without immunization programs. World travel increases the chances of these diseases spreading. Generally, adults born before 1957 are considered immune to measles and mumps. The CDC advises most adults born in 1957 or afterward...

Read the MMR Vaccine for Adults article > >

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

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

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.

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