Flu

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Flu Overview

What is Flu?

Influenza (flu) is a highly contagious disease caused by influenza viruses. Symptoms include fever, sore throat, and cough. The disease is spread through the air by coughing or sneezing. Read more about flu and how it affects people on the Centers for Disease Control and Prevention (CDC) website.

Read more facts about the flu on our Flu Facts web page.

What are the symptoms of flu?

Flu has the following symptoms:

  • Fever
  • Headache
  • Tired
  • Dry cough
  • Sore throat

Who is at risk?

Everyone is at risk for getting sick from flu. Certain people are at greater risk, including:

  • All children younger than 5 years of age, with highest risk for children and infants younger than 2 years of age.
  • People 65 years and older.
  • People of any age with certain health conditions like asthma and lung diseases, blood disorders, endocrine disorders such as diabetes, heart disease, neurological conditions, kidney or liver disorders, a body mass index (BMI) of 40kg/m or higher, and  metabolic disorders such as  sickle cell disease.
  • People with a weakened immune system due to disease or medications.
  • People who have had a stroke.
  • People with certain disabilities, especially those who may have trouble with muscle or lung function, or difficulty coughing, swallowing, or clearing fluids from their airways.
  • Pregnant people and people up to two weeks after the end of pregnancy.
  • People who live in nursing homes and other long-term care facilities.
  • People from certain racial and ethnic groups, including non-Hispanic Black, Hispanic or Latino, and American Indians and Alaskan Native people.

Find translated information about those at higher risk from flu on our Are you at high risk for flu web page, which includes information in traditional and simplified Chinese, Spanish, Russian, and Vietnamese.

Limit the spread of flu

There are a number of things you can do to limit the spread of flu.

  1. Everyone six months and older should get a flu vaccine every year.
  2. Avoid close contact with people who are sick.
  3. Wash your hands, cover your mouth and nose, and stay home if you are sick.

Flu Vaccine

When do people get flu vaccine?

Everyone six months and older should get a flu shot every year.

Children under nine years of age may need two doses of flu in one season if they’ve never received a flu vaccine before.

Flu viruses can spread throughout the year. However, flu activity usually increases in the fall and winter in North America. Try to get your flu vaccine by the end of October to be protected before flu cases rise. After you get your vaccine it takes two weeks for the vaccine to start working.

For adults aged 65 and older

There are special kinds of flu shots for people aged 65 and older that are different than regular flu shots. High dose, adjuvanted, and recombinant flu shots  are recommended for people aged 65 or older. These vaccines  give a stronger immune response than regular flu shots, offering better protection against flu illness for older adults. Your doctor will help you understand which flu shot is right for you.

Grandparents… Protect your loved ones against flu and whooping cough (PDF)

Who should not get a flu vaccine?

Infants 6 months and younger are too young to get the flu vaccine, but are high risk for being hospitalized due to flu complications. Caregivers should get their annual flu vaccine to keep themselves healthy and prevent the spread of flu to newborns.

People with severe allergies to any ingredient in the vaccine should not get a flu vaccine.

Pregnant people should not get FluMist, a flu vaccine given in the nose.

For more information, visit the Centers of Disease Control and Prevention’s (CDC) web page, Who Needs A Flu Vaccine. 

What are the side effects of flu vaccine?

Most people experience minor or no side effects. The most common side effects of flu vaccine include:

  • Soreness, swelling, and redness where the vaccine was given.
  • Fever.
  • Headache, pain or achiness in the muscles or joints.

This vaccine is continually monitored for safety. The benefits and side effects of this vaccine outweigh the risk of getting flu.

If you or your child may have a side effect from a vaccine, talk to your healthcare provider. You or your healthcare provider can file a report with the Vaccine Adverse Event Reporting System (VAERS). Find more information the VAERS website.

Why is flu vaccine important?

Getting the flu vaccine can help keep you from getting sick with flu. Additionally, it can reduce the severity of flu in people who are vaccinated but still get the flu.

Flu vaccines are reviewed and updated each year because the influenza virus is constantly changing. This is why it is important to get a flu vaccine every year.

Getting vaccinated protects yourself, your family, and others in the community. This protects people who can’t get vaccinated, such as those with weakened immune systems and infants.

Vaccine Information Statement and Resources

The Vaccine Information Statement (VIS) is given to people at the time of vaccination. It explains the benefits and risks of the specific vaccination.

Read the current inactivated flu VIS or the intranasal flu VIS from the Centers of Disease Control and Prevention (CDC).

Additional resources for the public

Additional resources for health care providers

Childhood Vaccine Program

The Washington State Childhood Vaccination Program provides vaccines to children 18 years of age and younger at no cost. The Washington State Adult Vaccine Program also provides vaccine to participating providers for adults 19 years of age and older who are uninsured. Flu vaccine is included in these programs.

View participating health care providers on the Department of Health’s Vaccine Provider Map.