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Myths and Facts About Influenza (Flu)

Myth: Flu vaccines can cause flu.

Fact: Flu vaccines are made with flu viruses that are either weakened, inactivated (killed), or recombinant (made without influenza viruses or eggs). Therefore, flu vaccines cannot cause flu. It typically takes 2 weeks for the flu vaccine to become effective and during those 2 weeks, it is still possible for a vaccinated individual to get flu or another respiratory virus.

Myth: Flu vaccination is not necessary every year.

Fact: Immunity from the flu vaccine declines over time, so annual vaccination is critical to provide the best protection. And since the vaccine may change each year to match circulating flu viruses, it is important to get vaccinated annually. The Centers for Disease Control and Prevention (CDC) recommends annual vaccination for all individuals age 6 months and older.

Myth: Healthy people don’t need a flu vaccine.

Fact: Anyone can get the flu, even young, healthy people. Getting vaccinated each year is important for everyone age 6 months and older. And vaccination can help prevent the spread of the virus to others who may be vulnerable to flu and related complications.

Myth: The flu is nothing more than just a bad cold.

Fact: Flu is not the same as a common cold—it can be far more serious, and can cause high fever, headaches and body aches, chills, and severe fatigue for up to 2 weeks or more. Flu can also lead to more serious complications, even death. On average, flu causes millions of illnesses, hundreds of thousands of hospitalizations, and tens of thousands of deaths in the US each year.

Myth: There is nothing you can do if you get the flu.

Fact: Know the symptoms. If you, your child, or a loved one gets sick, contact a healthcare professional immediately to discuss treatment options. Prescription antiviral drugs can make the illness milder, make you feel better faster, and may also prevent serious flu-related complications.

Myth: Vaccines can be dangerous and may have adverse health effects.

Fact: Most people do not experience serious side effects from flu vaccines. Some may experience a sore arm at the injection site, fever, muscle pain, and feelings of discomfort or weakness. These side effects typically last 1-2 days after vaccination and are much less severe than actual flu illness. The risk of a flu vaccine causing serious harm or death is extremely small.


Updated September 2021

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