- Flu activity is rated high to very high in most of the U.S.
- Influenza A, subclade K, is the dominant circulating flu variant this season.
- CDC stresses the importance of hygiene and distancing to prevent virus spread.
The 2025-26 flu season is no longer a guess, but rather a force that’s moving at a “high” or “very high” rate in nearly all states and jurisdictions, according to the Centers for Disease Control and Prevention. And many more cases are expected in coming days as influenza activity increases.
Thirty-two states and jurisdictions have very high flu activity, while 16 are listed as high.
The Utah Department of Health and Human Services reports that while COVID-19 and RSV activity in Utah is low, flu activity is on the rise.
Between Sept. 28 and Dec. 27, 2025, there were more than 94,000 lab confirmed cases of flu in the U.S. In just the week ending Dec. 27, 33,301 people were hospitalized, a child died (there have been nine pediatric deaths this season) and “seasonal influenza activity is elevated and continues to increase across the country,” according to the Centers for Disease Control and Prevention.
The CDC said those numbers are low. The public health giant estimates that there have been at least 11 million illnesses, 120,000 hospitalizations, and 5,000 deaths from flu so far this season.
The version of the flu that’s circulating the most heavily is influenza A, subclade K, a variant that just misses the flu vaccine formula, though the vaccine is expected to reduce severe illness and prevent hospitalizations and deaths.
The CDC is recommending that everyone 6 months and older who has not been vaccinated this year do so.
For those who do get the flu, the CDC said that prescription flu antiviral drugs are available and should be started quickly, especially for those at high risk of having flu complications.
Respiratory syncytial virus and COVID-19 are also circulating, and so is the common cold. It’s also possible to get more than one virus at a time.
What does the flu do?
Flu is fairly easy to spot even without a lab test because it tends to come on suddenly and symptoms are generally more severe. One minute you’re fine and the next you have symptoms such as:
- Fever
- Cough
- Sore throat
- Headache
- Congestion or a runny nose
- Fatigue
- Body aches
- Diarrhea and vomiting are sometimes symptoms, particularly in children.
The CDC advises seeking medical attention promptly for symptoms such as trouble breathing, prolonged pain or pressure in the chest or abdomen, dehydration, seizures, high temperatures that won’t go down with medication, any fever in babies under 12 weeks old, confusion or difficulty arousing someone who is ill. In children, bluish lips or face also indicates the need for immediate care.
Young children, older adults (65+) and those with weak immune systems are the most likely to have severe illness.
Prevention tips
Besides being vaccinated, the CDC offers tips for preventing spread of respiratory viruses when you’re ill, as well as strategies to avoid being the recipient of someone else’s illness.
- Avoid close contact. Physical distance reduces the risk of spreading or getting a respiratory illness.
- If you’re sick, stay home and away from others. That advice holds for a full 24 hours after your symptoms are better and you have not had a fever without using fever-reducing medication.
- Practice good hygiene, including covering your nose and mouth and regularly washing your hands. Per CDC, “clean hands save lives.”
- Sneeze into your elbow.
- Clean and disinfect surfaces that people are prone to touch.
- Get lots of sleep, stay active, eat well and drink plenty of fluids.