Bad Flu Season

The flu season has gotten off to a bad start in the United States, and a new flu variant may be driving more illness and hospitalizations. The U.S. Centers for Disease Control and Prevention (CDC) says that seasonal influenza (flu) activity is elevated and continues to increase nationwide.

The agency estimates that there have been at least 11,000,000 illnesses, 120,000 hospitalizations, and 5,000 deaths from the flu so far this season. In addition, the agency said there have been nine influenza-related pediatric deaths reported to the CDC this season.

The surge in flu activity in the United States is accompanied by a new variant called subclade K, a mutation of the influenza (A) H3N2 virus. According to the CDC, nearly all H3N2 viruses circulating in the country are from subclade K.

The H3N2 influenza virus is “quite common,” Jennifer Nuzzo, professor of epidemiology and director of the Pandemic Center at Brown University School of Public Health, said in a flu report published Dec. 19, 2025, by the Journal of the American Medical Association. But H3N2 has attracted attention because it has developed a large number of mutations.

“It’s changed enough that it gets its own subclade designation,” Nuzzo said.

According to the CDC, the 2025-2026 flu vaccine protects against three main seasonal influenza viruses: an A (H1N1) virus, an A (H3N2) virus, and a B/Victoria lineage virus.

Health officials are concerned that the current flu vaccine might not match the subclade K virus. However, they believe the vaccine still guards against serious illness.

Every year, the seasonal flu vaccine is formulated to target the most commonly circulating strains. The CDC explained that subclade K was first identified in August 2025, about six months after the season’s influenza vaccines had already been made. When it was first detected, there were very few cases of subclade K worldwide. But since then, the CDC said detections have increased and have led to either prolonged epidemics in some countries in the Southern Hemisphere or earlier than normal starts in some countries in the Northern Hemisphere. The United States has not experienced an earlier start to its flu season, the CDC said.

Most States Have Very High Flu Activity

The flu has hit New York harder than some other states. The New York Health Department reported 71,123 positive flu cases for the week ending Dec. 20, 2025, a 38 percent increase over the previous week. The department noted that this was the highest ever recorded in one week since influenza became reportable in 2004. There have been 189,312 positive flu cases reported in New York this season to date.

In addition to New York, the CDC’s FluView Interactive Map shows the following states with very high flu activity levels during the week ending Jan.3, 2026:

The CDC’s map shows that these states had a high level of flu activity during the same time period:

The U.S. Virgin Islands reported minimal cases, while Montana, South Dakota, Utah, and the Northern Mariana Islands reported low flu activity for the week ending Jan. 3, 2026, according to the CDC’s map. Arizona, Mississippi, Vermont, Wyoming, and West Virginia reported moderate activity during the same time period.

The CDC tracks flu activity based on such indicators as the percentage of influenza-like illness visits to outpatient health clinics, the rates of flu-related hospitalizations, and the percentage of deaths resulting from flu.

While flu cases are increasing, the number of people getting flu shots is decreasing. The CDC estimated that 50.3 million flu vaccinations have been given at physician medical offices so far in the 2025-2026 season, compared to 59.3 million flu shots administered in the 2024-2025 season.

Signs and Symptoms of the Flu

Flu symptoms can come on quickly. According to the CDC, flu sufferers often feel signs and symptoms that include:

It’s important to note that not everyone with the flu will have a fever.

How to Prevent Getting the Flu and Stop Its Spread

Health officials say the first step in preventing the flu is to get a flu shot to reduce the risk of flu-related illnesses, serious flu complications, or even death. The CDC recommends that everyone six months and older who has not been vaccinated this season get vaccinated against the flu. Flu shots are available at a doctor’s office, health clinics, and retail pharmacies.

To help stop the spread of influenza, the New York State Health Department offers the following tips:

Also, the health department recommends that if you are sick, stay home.

Source Link:

https://www.usatoday.com/story/news/health/2025/12/27/flu-cases-rising-new-york-colorado-louisiana/87927257007/
https://www.cdc.gov/fluview/surveillance/2025-week-52.html
https://health.ny.gov/press/releases/2025/2025-12-26_flu_cases.htm
https://jamanetwork.com/journals/jama/article-abstract/2843197
https://gis.cdc.gov/grasp/fluview/main.html#a22
https://www.cdc.gov/flu/season/2025-2026.html#:~:text=Composition%20of%202025%2D2026%20flu,Victoria%20lineage)%2Dlike%20virus
https://www.cdc.gov/fluvaxview/dashboard/adult-vaccinations-administered.html
https://www.cdc.gov/flu/signs-symptoms/index.html