Influenza

A woman receiving a flu shot from a doctor in a clinical setting.

How to get a flu shot?

UT Southwestern is offering flu shots to current patients at our retail pharmacies and doctors’ offices. Check with your providers about availability. Flu shots will also be available in several pop-up kiosks across campus and at our locations in Frisco and Fort Worth:

- Aston Building Lobby
- Professional Office Building 2 Lobby
- Outpatient Building Lobby
- West Campus Building 3 Lobby
- Campus Pharmacy
- University Hospital Retail Pharmacy
- Pharmacy at Fort Worth
- Pharmacy at Frisco
- Pharmacy at RedBird

At UT Southwestern Medical Center, we are committed to preventing and treating seasonal influenza and its complications.

Through education, vaccinations, and prompt treatment, we work to limit transmission of this highly contagious respiratory virus.

Expert Prevention and Treatment of Influenza

Influenza, more commonly known as the flu, is a viral infection that affects the respiratory system (nose, throat, and lungs).

It causes mild to severe illness; in the most serious cases, it can lead to significant inflammation of the lungs or even death. According to estimates from the Centers for Disease Control and Prevention (CDC), more than 44,900 people in the U.S. died from flu complications during 2023-2024 flu season.

UT Southwestern is dedicated to providing the highest level of care for the flu. As leaders in clinical care, we recommend patients get the annual flu vaccine, which is the most effective method for preventing flu and its complications. The faculty at UT Southwestern also performs innovative research in the development of treatments for various infectious diseases, including influenza.

Flu-like symptoms to watch for include fever, muscle aches, cough, congestion, runny nose, and sneezing.

Flu symptoms can be similar to those of COVID-19, but, as the CDC notes, influenza and COVID-19 are caused by different viruses.

Causes and Risk Factors of Influenza

Flu is caused by strains of influenza viruses that travel in the air when an infected person talks, sneezes, or coughs. These respiratory droplets can make their way into the mouths or noses of nearby people and infect healthy cells and spread. People can also become infected by touching a surface that has the virus on it and then touching their face.

The virus can affect anyone, but certain people have a higher risk of being infected or having more serious illness once they are:

Children younger than 5
Adults 65 or older
People with a body mass index (BMI) of 40 kg/m2 or higher
Those with chronic health conditions or weakened immune systems from illnesses such as diabetes, kidney disease, heart disease, or lung conditions such as chronic obstructive pulmonary disease (COPD) or asthma

Avoiding Influenza

Influenza vaccine

Getting the influenza vaccine, often called a flu shot, is one of the most important actions people can take to protect themselves from infection. The flu shot is particularly important for people who work in schools or the health care profession. While vaccine effectiveness varies year to year, the vaccine can reduce the risk of flu illness by 40% to 60% among the overall population when the vaccine matches the spreading flu viruses during the latest flu season.

When to get a flu shot

Flu season usually runs from November through April in the Northern Hemisphere. Because it takes the vaccine a few weeks to be effective, it’s better to get it early in the season. We recommend getting the vaccine in September or October. If you are pregnant and will be in your third trimester in September or October, it is recommended you get the flu vaccine earlier to allow enough time for protection to transfer to your unborn child.

What type to get

There are several types of flu vaccines, and our providers can help patients decide which one is right for them:

Injection: Given with a needle, typically in the arm
Nasal spray (live, attenuated influenza vaccine): May be given to people ages 2 through 49 who prefer a spray over needles; it should not be given to women who are pregnant
High-dose vaccine: For people 65 or older
Jet injector: For people who prefer to avoid needles
Egg-free vaccine: For people who have an egg allergy or who otherwise just prefer to avoid vaccines with eggs

The vaccine can have side effects, which are usually mild and go away within a few days. These include:

Tenderness, redness, or swelling (at the site of the shot)
Runny nose (for the nasal spray)
Fever
Muscle aches
Headache
Nausea

How effective is the flu vaccine?

The influenza vaccine tends to frustrate people because, while it is the best way to protect against the virus, it is not 100% effective. Influenza is a respiratory virus that mutates, or changes, frequently. That’s why it requires annual vaccinations.

Every year, researchers monitor viruses worldwide and update the flu vaccine to combat what they think will be the dominant circulating strains that will cause flu that year. The predictions of these experts are pretty accurate but not perfect. Recent studies by the CDC estimate the vaccine reduces the risk of influenza by 40% to 60% in the overall population. A study conducted from 2012 to 2015 found that the vaccine reduced the risk of being admitted to the intensive care unit for the flu by 82%. Studies have also shown that being infected with the flu can lead to a higher risk of heart attack.

Researchers at the National Institutes of Health are hard at work developing a universal flu vaccine that would protect against multiple strains for up to 10 years. For now, UT Southwestern’s infectious disease specialists say there is no debate: The flu vaccine is the best defense against influenza.

Other ways to stay safe

In addition to getting a flu vaccine, you can protect yourself and others from the virus by:

Washing your hands with soap or alcohol-based hand sanitizer frequently, for at least 20 seconds at a time
Wearing a mask (and changing it if it becomes soiled from a runny nose or cough)
Not sharing silverware, drinks, towels, or personal hygiene items
Covering your nose and mouth with a tissue or the inside of the elbow when you cough or sneeze
Sanitizing high-touch surfaces, such as doorknobs, light switches, and toilet handles
Taking precautions by not going to the office and not traveling if you do not feel well and not sending children to school if they don’t feel well
Contacting your provider if you have flu symptoms, so you can be tested and begin treatment as soon as possible

Influenza Symptoms

The flu may resemble a common cold, though the symptoms are usually more severe and longer lasting. Signs of the flu include:

Fever or chills
Sore throat
Cough
Muscle or body aches
Stuffy or runny nose
Headaches
Fatigue
Vomiting and diarrhea (more common in children)

In some people, flu causes complications. High-risk groups include:

Adults 65 or older
Children 5 or younger
Pregnant women, or women who have recently given birth
People with chronic conditions such as heart disease, asthma, or diabetes

These severe complications can include:

Bronchitis
Pneumonia
Respiratory failure requiring hospitalization or treatment in the intensive care unit
Inflammation of the heart (myocarditis), brain (encephalitis), or muscle tissues (myositis, rhabdomyolysis)

A woman and a child wearing face masks, sitting together in front of a masked doctor.

Navigating the Season of Flu and COVID-19

UT Southwestern specialists offer practical advice for staying safe during this particularly complicated influenza season.

Learn more

Diagnosing Influenza

To diagnose flu, our providers begin with a thorough evaluation that includes a:

Discussion of symptoms
Review of personal and family medical history
Physical exam

Based on the exam, we may perform a test for influenza, which involves swiping the inside of the patient’s nose or the back of the throat with a swab. The swab is then tested for the virus. With the rapid test, we typically have the results in about 20 minutes; other tests can take one or two days for results to return.

Influenza Treatment

Our providers will recommend a treatment plan based on each patient’s situation. We always recommend drinking plenty of fluids and avoiding contact with others. Tamiflu is especially recommended for people who are at high risk of complications or for those who have signs of a more serious infection.

Tamiflu or other antiviral drugs with activity against influenza can help shorten the duration of the illness and prevent serious complications. For the best results, patients should take antiviral drugs within three days of coming down with the flu.

Main Flu Myths

Eight infectious disease experts at UT Southwestern Medical Center respond to common myths about the flu with facts.

Frequently Asked Questions

Are there new recommendations for the 2024-2025 flu season?

The Food and Drug Administration (FDA) finalized its recommendations for the 2024-2025 flu season.

It advises that the trivalent influenza vaccine contain the following:

Egg-based vaccines

an A/Victoria/4897/2022 (H1N1)pdm09-like virus;
an A/Thailand/8/2022 (H3N2)-like virus; and
a B/Austria/1359417/2021 (B/Victoria lineage)-like virus

Cell- or recombinant-based vaccines

an A/Wisconsin/67/2022 (H1N1)pdm09-like virus;
an A/Massachusetts/18/2022 (H3N2)-like virus; and (updated)
a B/Austria/1359417/2021 (B/Victoria lineage)-like virus

Will this year’s vaccine be a good match against circulating viruses?

It’s difficult to predict whether the influenza vaccine will be a good match for this year's circulating flu strains because the viruses are constantly changing. It’s important to remember that multiple viruses usually circulate during any one season. Even if the effectiveness of the vaccine is reduced against one virus, it can still help prevent flu caused by the other circulating viruses because the vaccine protects against three or four strains.

Who should get the flu vaccine?

It is recommended that all people age 6 months or older receive an annual vaccination, with rare exceptions. Vaccination is particularly important for people who are at high risk of serious complications from influenza, such as people 65 or older, people of any age with certain chronic medical conditions, pregnant women, and children younger than 5. People with severe, life-threatening allergies or reactions to the flu vaccine or any of its ingredients should not get one.

What is the difference between the shot and the nasal spray?

The flu shot is injected into your upper arm. It is made from dead influenza virus and cannot give you the flu. It is recommended for all people age 6 months and older. The nasal spray (sprayed into the nose) is made from a weakened live virus that cannot give you the flu. The nasal spray can be taken by people between ages 2 and 49 who are in good health and not pregnant.

What are the side effects of the flu vaccines?

Common side effects from flu vaccines include soreness, redness, and/or swelling where the shot was given, and sometimes headache, fever, nausea, muscle aches, and fatigue.

Besides getting vaccinated, how can people protect themselves from the flu?

Avoid close contact with people who are sick.
If you are sick, limit contact with others to keep from infecting them.
Cover coughs and sneezes.
Wash your hands with soap and water or use an alcohol-based hand sanitizer.
Avoid touching your eyes, nose, and mouth.
Clean and disinfect surfaces and objects that may be contaminated with viruses that cause flu.
Wear a mask in public settings where you cannot physically distance or there is poor air flow.

Will COVID-19 antibodies protect me against the flu?

No. COVID-19 antibodies do not protect against the flu because influenza and COVID-19 are caused by different viruses.

Should I get a flu vaccine if I’ve had COVID-19?

Yes. Even if you’ve had COVID-19, you still need a flu shot because they are different viruses that cause two different diseases.

How does the flu vaccine differ from the COVID-19 vaccine?

Coronavirus vaccines and flu shots use distinctly different technologies against different viruses, but they still have the same job of teaching our immune system how to recognize and attack a virus. Both shots may trigger side effects such as fatigue, chills, and low-grade fever. The COVID-19 vaccine appears to be even more effective at preventing severe disease due to COVID-19, along with hospitalization and death.

Where can I get a flu vaccine at UT Southwestern?

UT Southwestern is offering flu shots to current patients at our retail pharmacies and doctors' offices. Check with your providers about availability.