Flu Facts

The flu is a disease caused by flu viruses that infects the nose, throat, and lungs. It can cause moderate to severe illness, including death.

You can get the flu any time of year, but it is more active in the fall and winter months.

People with flu often have:

• Fever
• Cough
• Sore throat
• Runny or stuffy nose
• Body aches
• Fatigue (tiredness)
• Headache
• Vomiting or diarrhea (this is more common in kids than adults)

If you or someone you know has these symptoms and they are severe, contact your doctor, nurse, or clinic as soon as possible. The best way to tell if you have flu is for a health care provider to swab your throat and have a lab confirm the diagnosis.

The flu spreads easily from person to person through coughs and sneezes. You can spread the flu to others before you know that you are sick. Adults can infect others one day before they show symptoms, and up to five days after they get sick. Kids can spread the virus for 10 or more days.

Yes. Viruses that cause the flu change often. If you had the flu or flu vaccine in the past you can get infected with a new strain of the flu. That's why it's important to get a flu vaccine every year.

The best way to prevent the flu is to get a flu vaccine each year.

You can help stop the spread of flu and other respiratory illness like coronavirus by covering your coughs and sneezes, washing your hands for 20 seconds with soap and water, wearing cloth face coverings, and staying home when you are sick.

The flu is unpredictable and can be severe, especially for older people, young kids, pregnant people, and people with certain health conditions. These groups are at a greater risk for serious flu-related complications, including:

• Pneumonia
• Ear infections
• Sinus infections
• Loss of fluids (dehydration)
• Worsening of chronic medical conditions (asthma, congestive heart failure, or diabetes)

The inactivated influenza vaccine, or flu vaccine (PDF), contains inactivated (killed) viruses.

This season, all available flu shots are trivalent (protects against three strains). | Spanish

Live attenuated influenza vaccine (LAIV) (PDF) also called “nasal spray” flu vaccine, is approved for use in non-pregnant individuals, 2 years through 49 years of age. People with some medical conditions should not receive the nasal spray flu vaccine. Learn more by visiting the CDC's nasal spray vaccine FAQ page.

The intradermal flu vaccine is injected into the skin instead of the muscle and uses a smaller needle than the regular flu vaccine.

Yes. There are special kinds of flu vaccine for adults aged 65 and older. These vaccines are made to give a stronger immune response and more protection than standard flu vaccines. Ask your provider or pharmacist which vaccine is right for you.

Yes. People with egg allergy may receive any flu vaccine (egg based or non-egg based) that is otherwise appropriate for their age and health status; additional safety measures are no longer recommended.

No. Flu vaccine cannot give you the flu. Flu vaccines are made with either inactivated (killed) virus, weakened (attenuated) virus, or through methods that do not use the flu virus at all (recombinant flu vaccine).

No. Flu vaccine will not protect you from coronavirus, colds, or other viruses. The flu vaccine contains the flu virus strains that research suggests will be most common that year.

Getting vaccinated each fall, will protect you throughout fall, winter, and spring. Unless you are a child getting a flu vaccine for the first time, you only need one flu vaccine per year.

People who have been vaccinated against flu can still sometimes catch the flu, but their flu illness is usually less severe. Studies show flu vaccination to have other benefits like reduced deaths, reduced admissions to the Intensive Care Unit (ICU), and reduced length of hospital stays.

It takes about eight to ten days after a single dose of the vaccine to create a strong immune response in most healthy adults. If you're planning to travel, be sure to get your flu shot at least two weeks before your trip.

All children in Washington can receive recommended vaccines at no cost through age 18. The provider may charge a fee to give the vaccine, called an administration fee. You can ask for this fee to be waived if you cannot afford it.

Most insurance plans, including Medicaid and Medicare part B, cover the cost of flu vaccine every year for adults.

Adults without insurance, or whose insurance doesn't cover the flu vaccine may be able to receive it at no cost this year. Talk to your local health department about availability and locations.

The effectiveness of the flu vaccine changes from year to year depending on:

• The match between the flu strains in the vaccine and the flu strains that are circulating
• The age and health of the person being vaccinated

No flu vaccine is 100 percent effective, but they give moderate protection for about one year and can help reduce the severity of flu disease if you do get sick.

For more information, visit the CDC's Benefits of the Flu Vaccine web page.

Yes, you can get the flu vaccine and COVID-19 vaccine on the same day. However, you should not delay getting either vaccine just for convenience. Get your updated COVID-19 vaccine or booster as soon as you are eligible. It is ideal to get your flu vaccine by the end of October so that you are protected during peak flu activity. If you get vaccinated after October, it’s not too late; you can still get the vaccine to protect yourself from the flu.

• Call your doctor, nurse, or clinic
• Visit your local pharmacy
• Check the Vaccines.gov
• Contact your local health department
• Call the Help Me Grow Washington Hotline at 1-800-322-2588.

Clinics and pharmacies have special safety guidelines in place to give vaccinations during the COVID-19 pandemic. Some clinics ask you to wait outside or in your car until your appointment time to limit the number of people in the building. This year there may be options like drive-through vaccination clinics. Call your clinic or pharmacy and ask what kind of safety procedures they follow.

Some grocery stores have special hours for adults over 65 and people with compromised immune systems. Those hours might be a good option to visit the pharmacy for a vaccination.

The Department of Health recommends a yearly flu vaccination for everyone aged 6 months and older, including:

• Pregnant and nursing people | Spanish | Russian | Vietnamese | Traditional Chinese | Simplified Chinese

Some people are at greater risk and are strongly encouraged to get a flu vaccine, including:

• Adults age 65 and older
• Young kids, especially kids under age 5
• Kids and adults of any age with certain chronic health conditions or special health care needs, such as asthma, diabetes (type 1 and 2), heart disease, neurologic conditions, and certain other long-term health conditions
• Pregnant women
• Health care professionals and caregivers of people in any of the above groups
• American Indians and Alaska Natives

Experts from the Food and Drug Administration (FDA), World Health Organization (WHO), and the CDC identify flu virus strains that are the most likely to cause illness during the upcoming year. These experts make up the Advisory Committee on Immunization Practices (ACIP) and every year they meet to make recommendations for flu vaccine use in the United States.

You can learn more by visiting the FDA website and the CDC's Summary Recommendations for the 2023-2024 flu season.

Yes. Flu vaccines have a very good safety record over the last 50 years. The vaccine is made and rigorously tested each year.

Like any medication, vaccines may have side effects. Every year, the CDC works closely with the FDA, health care providers, state and local health departments, and other partners to ensure the highest safety standards for flu vaccines. The CDC also works closely with the FDA to monitor unexpected health problems following vaccination.

Visit Influenza Vaccine Safety (CDC) for more information about vaccine safety. | Spanish

The CDC and the FDA, (along with state and local health departments, health care providers, and other partners) watch closely for any signs that the flu vaccine causes unexpected problems and investigate unusual side effects quickly. Side effects (also called adverse events) may not be related to vaccination, but just happen around the same time. Tracking and investigation help us figure out which side effects are truly caused by vaccination, and which are not.

For more information about vaccine safety:

• Vaccine Safety | Spanish
• Why it's important to monitor vaccine safety (CDC)

Some people do not get any side effects from the vaccine, but some do. Most side effects from the flu vaccine are mild. The most common side effects are:

• Soreness, redness, tenderness, or swelling where the vaccine was given
• Fainting (mainly in adolescents)
• Headaches
• Muscle aches
• Fever
• Nausea (upset stomach)

If these problems occur, they usually begin soon after a person receives the vaccine, and last for one to two days. Life-threatening allergic reactions are rare. If they do occur, they usually happen within a few minutes to a few hours after the vaccine was given. If your doctor or pharmacist is concerned you may have an allergic reaction or a side effect such as fainting, they may ask you to wait at the clinic or pharmacy for 15 minutes after you get the vaccine.

A vaccine information statement will be provided at the time you get your vaccine about benefits and risks, what side effects to look for after vaccination and how to report side effects.

If you think you or your child may have a side effect from a vaccine, talk with your health care provider and either:

• Ask your health care provider to file a report with the Vaccine Adverse Event Reporting System (VAERS), or
• File a report yourself with VAERS (follow instructions for online reporting). | Spanish

Yes! Mercury-free flu vaccines are available and meet the requirements of the mercury-limiting law that went into effect in Washington state on July 1, 2007. For more information, see Thimerosal Laws.

How to stop the spread of flu:

• Get a flu vaccine every year.
• Wash your hands frequently with soap and water.
• Use alcohol-based hand gel or disposable wipes.
• Cover your coughs and sneezes with a tissue or your upper sleeve, not your bare hand.
• Use a tissue to wipe your nose, then throw the tissue away and wash your hands.
• Stay home and away from others while you or your family members are sick.
• Wear a cloth face covering if you have to go out in public.

Yes. Medications called antiviral drugs can be used to treat the flu. These drugs must be prescribed by a medical provider.

It's important that antiviral drugs be used early to treat people who are:

• Very sick with the flu (for example people who are in the hospital).
• Sick with the flu and at high-risk for serious flu complications (either because of their age or because they have a high-risk medical condition).

People who get the flu who are otherwise healthy do not need to be treated with antiviral drugs.

You can find more information on the CDC's "What you should know about flu antiviral drugs" webpage. | Spanish

If you have severe flu symptoms, contact your doctor, nurse, or clinic as soon as possible, especially if you are at high risk of developing flu-related complications (CDC). The best way to tell if you have flu is for a health care provider to swab your throat and have a lab confirm the diagnosis. If you have the flu, your provider may prescribe antiviral drugs for treatment. | Spanish

The CDC recommends that you stay home from work, school, travel, shopping, social events and public gatherings for at least 24 hours after your fever is gone (without the use of fever-reducing medications), except to get medical care or for other essential trips.

1. Stay at home and rest
2. Avoid close contact with others in your house so you won't make them sick.
3. Drink plenty of water and clear liquids to prevent water loss (dehydration).
4. Ask your provider if you should treat your fever and cough with medicines you can buy at the store.
5. If you get very sick or are at high risk for flu complications (CDC) call your doctor. | Spanish

For more information about what to do if you get the flu, visit the CDC's webpage, Caring for Someone Sick. | Spanish