Influenza (Flu) Facts

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On this page:
What is influenza (flu)?
What are the symptoms?
Should I get a flu vaccine?
Who is most at risk for getting very sick from flu?
How is the flu different from a cold?
Can I get the flu from the flu vaccine?
When should I get vaccinated?
Do children need one or two doses of flu vaccine?
What type of flu vaccine should I get?
Flu vaccine and allergies
What can I do to protect myself and others?
What if I think I have the flu?
What about antiviral medicine?

What is influenza (flu)?

Flu is a contagious respiratory disease. It is not the same as the "stomach flu." Flu is caused by a virus that attacks the nose, throat, and lungs. It can cause mild to severe illness and at times can lead to death.

What are the symptoms?

Flu symptoms include fever, dry cough, sore throat, headache, extreme tiredness, and body aches. Not everyone will have a fever or experience all of these symptoms. Symptoms usually begin suddenly and might be severe enough to stop your daily activities.

Should I get a flu vaccine?

Yes. Everyone 6 months of age and older should get flu vaccine every year. Getting a flu vaccine helps protect you from getting the flu or getting very sick with the flu that could cause you to be hospitalized, or even die. It also can prevent you from passing it to people who could get very sick.

Who is most at risk for getting very sick from flu?

• People age 65 and older.
• Young children, especially those under 2 years old.
• Pregnant women.
• People with chronic health conditions such as asthma, diabetes, and heart disease.
• American Indian and Alaska Natives.

Although these groups are at highest risk, anyone can become very sick with flu.

How is the flu different from a cold?

Colds are generally less serious than the flu. With a cold, you're more likely to have a runny or stuffy nose, while the flu causes body aches, fever, and extreme tiredness. A person with a cold can usually keep up with their normal activities, but someone with the flu can't. Flu can result in serious health problems like pneumonia, bacterial infections, and hospitalization.

Can I get the flu from the flu vaccine?

No. Some people get a mild fever or have discomfort for a short time after being vaccinated, but this is a sign that your body is responding to the vaccine. It is not the flu. Also, because there are many viruses circulating in the fall, it is possible to get sick with a different virus around the same time they get flu vaccine.

When should I get vaccinated?

For best protection, flu vaccine is recommended in September or October, before flu season starts. But you can get it anytime during flu season which is typically October through April. You should get the flu vaccine even if you already had the flu this season.

Do children need one or two doses of flu vaccine?

It depends on the child's age and whether they got flu vaccine in the past. If your child is 6 months through 8 years old, he or she may need two doses at least four weeks apart. Ask your doctor or clinic.

What type of flu vaccine should I get?

There are several types of flu vaccine available. The type of vaccine you can get depends on things like your age, health conditions, if you're pregnant, and allergies. Your health care provider or pharmacist will know what type of vaccine you should get. The most important thing is to get vaccinated. Don't wait for a specific type of flu vaccine to be available.

• Trivalent vaccine - All flu vaccines are trivalent meaning they protect against three strains (or types) of flu: two A strains and one B strains. One of the B strains was removed as it has not been detected since 2020.
• High-dose vaccine - This vaccine is approved for persons 65 and older and contains four times the amount of vaccine protein of the traditional vaccine. This vaccine produces a stronger immune response in people 65 and older. People 18-64 years of age who have received a slid organ transplant should talk with their health care provider about the option to receive this vaccine.
• DNA technology (RIV) and cell-based flu vaccines – These vaccines are not made using chicken eggs like traditional flu vaccines. These vaccines may not be as widely available as traditional flu vaccines.
• Flu vaccine with adjuvant – This vaccine is approved for persons 65 and older and contains an adjuvant, which is a substance added to the vaccine to help create a stronger immune response. People 18-64 years of age who have received a slid organ transplant should talk with their health care provider about the option to receive this vaccine.
• Nasal spray flu vaccine – This vaccine is made with live flu viruses that have been weakened so they will not cause flu illness. It is approved for people ages 2 through 49 years. People who are pregnant or have certain medical conditions should not get the nasal spray flu vaccine.

Flu vaccine and allergies

People with an egg allergy can safely get a flu vaccine. Life-threatening allergic reactions to flu vaccine are very rare. Talk to your health care provider if you've had a life-threatening reaction to a flu vaccine. 

What can I do to protect myself and others?

• Get vaccinated.
• Avoid being around others who are sick.
• Cover your nose and mouth with a tissue when you cough or sneeze, or cough or sneeze into your sleeve.
• Wash your hands often with soap and water, or an alcohol-based, waterless hand sanitizer.
• Protect infants by not exposing them to large crowds or sick family members when flu is in your community.
• Do not share drinking cups and straws.
• Clean commonly touched surfaces often (doorknobs, refrigerator handles, phones, and water faucets).

What if I think I have the flu?

• Stay home if you are sick.
• Avoid contact with others.
• Rest and drink lots of fluids.
• If you are in a high-risk group, call your health care provider for advice.
• Seek immediate medical care if you have:
  • Difficulty breathing or shortness of breath.
  • Pain or pressure in the chest or abdomen.
  • Sudden dizziness.
  • Confusion.
  • Severe or persistent vomiting.
  • Flu-like symptoms that improve but return with worse fever and cough.

What about antiviral medicines?

Antiviral medicines can offer some protection if you have been exposed to flu. Contact your health care provider right away if you get sick with the flu and are at high-risk for complications from flu.