NEW YORK, Dec. 27, 2025 – A surge in influenza cases is sweeping across the United States, with New York reporting its highest weekly total ever recorded – 71,123 positive cases for the week ending Dec. 20, a staggering 38% increase from the previous week, according to the New York State Department of Health. It’s a particularly unwelcome development as holiday travel ramps up, potentially spreading the virus even further.
Flu Cases Spike Nationwide Amid New Strain Concerns
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The U.S. is experiencing a significant rise in flu activity, with a new variant adding complexity to prevention efforts.
- Flu cases are surging in multiple states, particularly in the Northeast.
- A new flu strain, subclade K, is circulating, raising concerns about vaccine effectiveness.
- Flu vaccination rates are down compared to last year, potentially exacerbating the outbreak.
- As of Dec. 16, flu infections were on the rise in 47 states.
The increase in seasonal flu activity mirrors patterns seen in previous seasons, the Centers for Disease Control and Prevention says. However, this year’s outbreak is complicated by the emergence of a new flu strain – subclade K, a variation of the influenza A(H3N2) virus – which has already caused outbreaks in Japan, the U.K., and Canada. While health officials are cautiously optimistic that the current flu vaccine still offers protection against severe illness, the potential for a mismatch is a concern.
What’s the best way to protect yourself from the flu this season? Getting vaccinated remains the most effective strategy, according to the CDC and the World Health Organization.
Fewer Americans Vaccinated This Year
Contributing to the growing concern is a decline in flu vaccination rates. So far in the 2025-2026 season, over 47.6 million flu vaccinations have been administered at retail pharmacies and physician offices, but that’s roughly 3 million fewer shots than were given at this point last year, according to the CDC.
The recent government shutdown, which lasted from Oct. 1 to Nov. 12, may have also played a role, according to Jennifer Nuzzo, professor of epidemiology and director of the Pandemic Center at Brown University School of Public Health. She noted in a Dec. 19 report published by the Journal of the American Medical Association that the shutdown likely led to a decrease in flu activity data, potentially impacting vaccination rates. “We’re potentially heading into a flu season that could be quite a doozy, and we know we’re starting it with fewer data and, more crucially, fewer vaccinations,” she said.
1,900 Deaths Reported So Far This Season
The CDC estimates that, so far this season, there have been at least 4,600,000 illnesses, 49,000 hospitalizations, and 1,900 deaths attributed to the flu. During the week ending Dec. 13, two pediatric deaths were reported, bringing the total number of flu-related pediatric deaths this season to three, the agency said.
Several states are experiencing particularly high levels of flu activity. Colorado, where the CDC reports “very high” activity, saw a 7% increase in emergency department visits with a flu diagnosis for the week ending Dec. 20, according to the Colorado Department of Public Health and Environment. Louisiana is also seeing a significant surge, with influenza accounting for 7% of emergency department visits – up from about 6% the previous week, according to the Louisiana Department of Health. All respiratory illnesses, including flu, COVID-19, and RSV, now account for nearly 9% of emergency visits in the state.
In New York City, visits to hospital emergency rooms with a flu diagnosis increased to 8.75% for the week ending Dec. 20, up from 6.76% the previous week, according to the New York City Department of Health and Mental Hygiene.
Which States Are Experiencing High Flu Activity?
The CDC’s FluView Interactive Map, based on outpatient visits for influenza-like illness, identifies the following states and territories with high or very high activity levels:
- Colorado (Very High)
- Connecticut (High)
- District of Columbia (High)
- Idaho (High)
- Massachusetts (High)
- New Hampshire (High)
- New Jersey (High)
- New Mexico (High)
- New York (Very High)
- New York City (Very High)
- Puerto Rico (High)
- Louisiana (Very High)
- Georgia (High)
- Maryland (High)
- Michigan (High)
- North Carolina (High)
- South Carolina (High)
Recognizing Flu Symptoms
Symptoms associated with the H3N2 strain are similar to those of other influenza viruses and include fever, cough, runny nose, fatigue, and muscle aches and chills.
To help prevent the spread of influenza, the New York State health department recommends frequent handwashing with soap and water for at least 20 seconds, or using an alcohol-based hand sanitizer. Other preventative measures include avoiding touching your eyes, nose, and mouth with unwashed hands, staying home if you are sick, avoiding close contact with sick individuals, covering coughs and sneezes with a tissue, and regularly cleaning and disinfecting frequently touched surfaces.
