Flu - FAQ

Although they are both contagious illnesses affecting the respiratory system, influenza (flu) and COVID-19 are caused by different viruses. COVID-19 is a disease caused by infection with a virus called SARS-CoV-2. Flu is caused by infection with influenza viruses. Flu and COVID-19 have similar symptoms, so it may be hard to tell the difference between them and testing may be needed to help confirm a diagnosis. Learn about the similarities and differences between the flu and COVID-19 here.

Flu occurs in the United States most often in the fall and winter. In Spokane County, the virus commonly peaks in January through mid-March.

In North America, September and October are generally good months to get vaccinated for flu. Getting vaccinated by the end of October is ideal. The timing of vaccination varies for certain groups, including the following:

• Adults, especially those 65 years and older, should generally not get vaccinated early (in July or August) because protection may decrease over time. However, for individuals who can’t return to their doctor or pharmacy at the appropriate time, early vaccination can be considered.
• Children can get their vaccine as soon as it’s available, even in July or August. The CDC recommends that some children between the ages of 6 months and 8 years get two doses of the flu vaccine if it is their first time receiving the flu shot. For those children, CDC recommends getting the first dose as soon as vaccine is available, because the second dose needs to be given at least four weeks after the first.
• People who are in the third trimester of pregnancy can also consider getting vaccinated early. This can help protect their infants during the first months of life (when they are too young to be vaccinated.

People with flu often have a sudden onset of:

• Fever
• Cough, which can be severe
• Sore throat
• Runny or stuffy nose
• Body aches
• Extreme fatigue (tiredness)
• Headache, which can be severe
• Some people may have vomiting or diarrhea – this is more common in children than in 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 by coughing and sneezing and can spread to others before a person knows they're sick. Adults can infect others one day before symptoms develop and up to five days after becoming sick. Kids can spread the virus for 10 or more days.

No, because there are many viruses that cause flu and they change from year to year. People who have had the flu or a flu shot in previous years may become infected with a new strain.

The best way to prevent flu is to get a flu shot each year. Using good health habits can also help stop the spread of flu: washing your hands, covering your cough, and staying home when you're sick.

Flu is unpredictable and can be severe, especially for older people, young kids, pregnant women, and people with certain health conditions. These groups are at greater risk for serious complications if they get the flu, including:

• Bacterial pneumonia
• Ear infections
• Sinus infections
• Dehydration
• Worsening of chronic medical conditions (asthma, congestive heart failure, or diabetes)
• Death

There are many different flu viruses and they are constantly changing. The composition of United States flu vaccines is reviewed annually and updated as needed to match circulating flu viruses. Flu vaccines protect against the viruses that research suggests will be most common.

No. Flu vaccine cannot give you the flu.

Some people incorrectly believe that they can become sick with flu from the vaccine. The flu shot only contains proteins from the flu virus, so the virus cannot reproduce itself and cause illness. In addition, the vaccine is injected into the muscle, which is not a means of flu transmission. It is not possible to get influenza from the vaccine.

Some people might feel a bit achy, tired or otherwise unwell for a day or two after getting the vaccine. This is because their immune system is responding to the vaccine and doing its job—mounting an immune response and creating antibodies. Sometimes people think that they have flu based on these symptoms, but they are just their body’s response to the vaccine.

There has been a change in the flu vaccine recommendations related to those who have an egg allergy. While some flu vaccines are made using eggs, there is only a tiny amount egg protein in them. There are flu vaccines that do not contain egg proteins. Previously, additional safety measures were recommended for administering egg-based vaccines to people with egg allergies. However, the CDC’s Advisory Committee on Immunization Practices (ACIP) has changed this recommendation to say that it is safe for people with an egg allergy to receive any flu vaccine that is appropriate for their age and health status. Even flu vaccines that do have egg proteins can be given safely to people with an egg allergy. Talk with your doctor about which flu vaccine is best for you.

See the CDC website for more information on flu vaccine and egg allergies. If you have had a severe allergic reaction to flu vaccine, regardless of the ingredient that caused the reaction, you should not receive future flu shots.

No. Flu vaccine will not prevent illness from other flu-like viruses. The vaccine contains strains of flu viruses that research suggests will be circulating during the flu season.

Important: the flu vaccine will not protect you from COVID-19. Flu vaccines are for the prevention of flu and COVID-19 vaccines are for the prevention of COVID-19.

Yes. Getting vaccinated in late September or early October will protect you throughout the flu season. Vaccination is the best way to protect yourself, your family, and your community from the flu. Be sure to check with your health care provider about getting a flu shot before flu viruses are circulating heavily in our area.

It takes about 8-10 days after a single dose for the vaccine to create a strong immune response in most healthy adults. It can take up to two weeks for people most vulnerable to serious complications from an influenza infection. If you're planning to travel, be sure to get your flu shot at least two weeks before your trip.

The Washington State Department of Health provides flu vaccine to all children under age 19 at no cost. Health care providers may charge an office visit fee and/or a fee to give the vaccine, called an administration fee. People who cannot afford the administration fee can ask their regular health care provider to waive the cost. Adults with insurance can talk to their insurance provider about coverage for flu vaccine.

Flu vaccine effectiveness is influenced by several factors. Every year the flu vaccine is formulated based on a best estimate of the predominant virus strains likely to be circulating that year. Some years the virus strain match is better than other years.

No vaccine is 100 percent effective at preventing illness. The flu vaccine can provide moderate protection and help reduce severity of disease, even during a season when the vaccine is not as well matched to the circulating strains as was predicted. Flu vaccine helps prevent illness for approximately 12 months.

For more information, visit the Centers for Disease Control and Prevention's CDC Seasonal Flu Vaccine Effectiveness Studies page.

• Call your doctor, nurse or clinic.

• Visit your local pharmacy.

• Check the vaccines.gov.

Spokane Regional Health District occasionally hosts community vaccination events that offer flu vaccine to those who are uninsured or under-insured. Find SRHD community clinics here.

Contact one of the following organizations for assistance with an on-site clinic.

Children who get a seasonal flu shot for the first time will likely need a second shot a month later. Since 2009, the Advisory Committee on Immunization Practices has recommended that all children age 6 months through 8 years old should get two doses of flu vaccine the first year that they are vaccinated against the flu. If your child had his first flu shot last year but only got a single shot, then this year he should get a flu shot and a booster shot. The second dose of vaccine should be administered at least 28 days after the first shot.

Yes. Flu vaccines have a very good and long safety record. Over the last 50 years, flu vaccines have been shown to be safe. The vaccine is made and rigorously tested in the same way each year, no matter what strains are included.

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

Visit these links on the CDC website for more information about vaccine safety:

• Influenza Vaccine Safety

• Influenza (Flu) Vaccine Safety

Side effects from the flu vaccine are typically mild, localized reactions. The most common side effects are soreness, redness, tenderness, or swelling where the shot was given; headache; muscle aches; fever; and nausea. If these problems occur, they usually begin soon after the shot and last one to two days. Fainting after vaccination occasionally occurs in adolescents.

Life-threatening allergic reactions are rare. If they do occur, it's usually within a few minutes to a few hours after the shot was given.

People who get the flu vaccine will be asked questions about their medical history to make sure it’s safe for them to receive the vaccine. A vaccine information statement will be provided to you at the time you get your shot. The statement explains benefits and risks associated with the flu vaccines, as well as signs of side effects to look for after vaccination and how to report side effects (also called adverse events).

If you think you or your child may have a side effect from a vaccine, be sure to discuss this with your health care provider and either:

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

Vaccines in multi-dose vials contain thimerosal to safeguard against contamination of the vial. Most single-dose vials and pre-filled syringes for flu vaccination and the nasal spray flu vaccine do not contain a preservative because they are intended to be used once.

These vaccines meet the requirements of the mercury-limiting law that went into effect in Washington state on July 1, 2007. The law requires that pregnant women and children under age 3 be given vaccines that are mercury-free (or thimerosal-free). Ask your provider or pharmacist about which vaccine is best for you.

Thimerosal is a preservative used to prevent contamination. Thimerosal contains a type of mercury called ethylmercury. Ethylmercury breaks down and leaves the body more quickly than methylmercury (the type of mercury found in the environment that is associated with mercury poisoning). Thimerosal is much less likely to accumulate in the body and cause harm.

Yes. There are medications called "antiviral drugs" that can be used to treat the flu. These drugs must be prescribed by a doctor.

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

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 except to get medical care. Your fever should be gone for 24 hours without the use of a fever-reducing medicine.

In children

• Fast breathing or trouble breathing
• Bluish skin color
• Not drinking enough fluids
• Not waking up or not interacting
• Being so irritable that the child does not want to be held
• Flu-like symptoms improve but then return with fever and worse cough
• Fever with a rash

In addition to the signs above, get medical help right away for any infant who has any of these signs:

• Being unable to eat
• Has trouble breathing
• Has no tears when crying
• Significantly fewer wet diapers than normal

In adults

• 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 then return with fever and worse cough

• Flu Prevention Poster (pediatric) 8.5 x 11
• Flu Prevention Poster (adult) 8.5 x 11
• What Am I Sick With? Poster 14 x 8.5

About Flu. Centers for Disease Control and Prevention. Updated September 20, 2022. Accessed September 5, 2024. https://www.cdc.gov/flu/about/index.html

CDC Seasonal Flu Vaccine Effectiveness Studies. Centers for Disease Control and Prevention. Updated August 14, 2024. Accessed September 5, 2024. https://www.cdc.gov/flu-vaccines-work/php/effectiveness-studies/index.html

Prevention and Control of Seasonal Influenza with Vaccines: Recommendations of the Advisory Committee on Immunization Practices (ACIP)—United States, 2024-25. Centers for Disease Control and Prevention. Accessed September 5, 2024. Updated September 5, 2024. https://www.cdc.gov/flu/professionals/acip/summary/summary-recommendations.htm

Similarities and Differences between Flu and COVID-19. Centers for Disease Control and Prevention. Updated March 20, 2024. Accessed September 5, 2024. https://www.cdc.gov/flu/symptoms/flu-vs-covid19.htm

Understanding Flu Viruses. Centers for Disease Control and Prevention. Updated December 2, 2022. Accessed September 5, 2024. https://www.cdc.gov/flu/about/viruses/index.htm