At a Glance
- Flu cases surge across the U.S., hospitalizations double.
- 7.5 million sick since Oct, 3,100 deaths, 5 pediatric deaths.
- Flu activity high/very high in 32 states, up from 17.
- Why it matters: Hospitals are strained and children under 5 are most at risk, so vaccination and early care are critical.
The latest CDC data shows the flu season is accelerating, with hospital admissions nearly doubling and a sharp rise in deaths, especially among young children.
Seasonal Surge & Hospital Impact
CDC data for the week ending December 20 reports flu activity at high or very high levels in 32 states, up from 17 the week before. At least 7.5 million people have fallen ill since the season began in October.
Hospitalizations nearly doubled in a single week, rising to 19,053, up from 9,944 the previous week. Overall deaths this season total 3,100, with pediatric deaths at 5, up from 2.
- New states with high activity: California, Nevada, Missouri, Arkansas, Alabama, Florida.
- States that moved to the top end of very high: New York, New Jersey, South Carolina, Louisiana, Colorado.
Who Is Hit Hardest
Infants and children up to age 4 are among the hardest hit, but school-aged kids and young adults are also increasing in numbers. Older adults and those with chronic conditions face higher hospitalization risk.
Beds are tight as COVID and RSV cases overlap with flu patients.
- Infants and children ≤ 4 years
- School-aged children and young adults
- Older adults with chronic conditions
The Virus & Symptoms
The dominant strain is Influenza A H3N2 subclade K, a fast-spreading mutated version that some call a “super flu.” WHO’s Dr. Wenqing Zhang notes the genetic shift does not yet indicate greater severity.
Symptoms mirror previous seasons: high fever, chills, cough, shortness of breath, and muscle aches. Unvaccinated individuals and those with underlying conditions may develop pneumonia, muscle breakdown, or seizures.
Patients also report headaches, fatigue, nausea, vomiting, and diarrhea. If shortness of breath or high fever persists, seek medical attention.
Vaccination & Other Viruses
It’s not too late to get the flu shot. This year’s vaccine includes an H3N2 component, though it isn’t a perfect match for the mutated subclade. Nonetheless, it remains effective at preventing severe illness and death.
Dr. Molly Fleece said:
> “That’s because the subclade mutated and spread after the vaccines were already selected for the year. It may mean that more people will be susceptible to getting the flu … but we know from historical data the vaccine is still very effective at preventing severe illness, hospitalization and death.”
Dr. Donald Yealy added:
> “This year’s seasonal vaccine can help provide protection.”
Other winter viruses are also circulating. COVID infections are slowly rising, especially in the South, Northeast, and Midwest. Norovirus remains high, and RSV is picking up in the South.
| Metric | Week ending Dec 20 | Week before |
|---|---|---|
| States high/very high | 32 | 17 |
| Hospitalizations | 19,053 | 9,944 |
| Overall deaths | 3,100 | – |
| Pediatric deaths | 5 | 2 |
With hospital capacity strained and multiple respiratory viruses overlapping, health officials urge vaccination and prompt care.
Key Takeaways
- Flu cases and hospitalizations are surging, especially among children under 5.
- The dominant H3N2 subclade K strain is driving the rapid rise.
- Vaccination remains the most effective defense against severe illness.
As the season moves toward its peak, staying up-to-date on flu activity and getting vaccinated can help protect you and your family.
