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Cold & Flu: The Seasonal Flu Vaccine

According to the CDC, the seasonal flu vaccine is the single best way to prevent getting the flu. Your child needs to get a flu vaccine every year, typically at the start of the flu season in early fall (the season lasts October through May). Why every year? The seasonal flu virus can mutate, so the virus that your child was vaccinated against last year may be slightly different than this year's strain. For example, the 2010-11 flu shot includes the H1N1 virus (swine flu), which the previous year's shot did not. This also explains why people who are vaccinated can still get the flu; the strain they catch can be different from the one they were vaccinated against. Protection against the flu usually begins about 2 weeks after getting the vaccine.

Should My Child Get the Vaccine?

The AAP recommends flu vaccines for:

  • Healthy children aged 6 months through 18 years
  • Children 6 months and older with serious health problems, such as lung disease, heart disease, a weakened immune system, or cancer
  • Household contacts and out-of-home caregivers of children with high-risk conditions and of all healthy children younger than 5 years
  • Health care professionals
  • Pregnant women

Children under 6 months of age should NOT be given the seasonal flu vaccine, nor should children with allergies to chicken eggs. If your child has a chronic health condition, talk to the doctor before getting your child vaccinated

How is the Vaccine Given?

The seasonal flu vaccine is administered via injection or a nasal spray. The injected vaccine contains an inactive virus for the body to build antibodies against, while the nasal spray is made with a weakened live virus.

The nasal spray (also called Live Attenuated Influenza Vaccine or LAIV, or FluMist) is approved for healthy people aged 2 through 49, but not pregnant women.  The injected vaccine is approved for those 6 months or older, whether healthy or having certain chronic medical conditions.

According to the CDC, children aged 2 through 9, will need two doses of the flu vaccine the first time they receive it.  The first dose “primes” the immune system, while the second dose administered 28 days or more after the first, provides the protection against the seasonal flu virus.  The two doses do not need to match, meaning your child can receive the live or inactivated virus for each dose.

What are the Risks of the Vaccine?

Purposefully inserting a bit of a virus in your child can seem scary, but side effects of the vaccine are minimal and last for at most 1 to 2 days. For the injected vaccine, side effects can include pain or redness at the injection site, a low-grade fever or aches. For the nasal spray, side effects include a runny nose, wheezing, vomiting, head or muscle aches and a fever.

One rare but serious side effect of the flu vaccine is an allergic reaction. If you notice your child having an allergic reaction to the vaccine within a few minutes or few hours of receiving it (signs include difficulty breathing, sudden weakness, hives, paleness and elevated heart rate), call your doctor immediately.

Another rare but serious side effect of the flu vaccine is Guillain-Barre Syndrome, a disease in which the body attacks its own nerve cells, causing muscle weakness and in some cases, paralysis. This can occur in at most, about one person per one million who receive the flu vaccines.