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Why So Many People Are Sick This Winter: Flu, COVID-19, RSV, and Norovirus on the Rise

Why So Many People Are Sick This Winter: Flu, COVID-19, RSV, and Norovirus on the Rise
Natalie Peeples / Axios
  • PublishedFebruary 19, 2025

If it feels like nearly everyone you know has been sick this winter, you’re not alone.

The United States is experiencing one of the worst flu seasons in more than a decade, alongside a surge in other viral illnesses, including COVID-19, RSV, and norovirus.

According to the Centers for Disease Control and Prevention (CDC), flu infections have reached their highest level since the 2010–2011 season, with hospitalizations and deaths outpacing COVID-19 for the first time since the pandemic began. Health experts warn that the severity of this flu season, combined with the spread of multiple viruses, is putting a strain on hospitals and emergency departments nationwide.

As of early February, the CDC estimates that there have been at least:

  • 29 million flu infections
  • 370,000 hospitalizations
  • 16,000 flu-related deaths

In comparison, last year’s flu season resulted in approximately 28,000 deaths. Experts predict this year’s numbers could surpass that total if cases continue at their current pace.

Dr. Jen Brull, president of the American Academy of Family Physicians, noted that this flu season is more severe than previous years, affecting people of all ages.

“It’s not that COVID-19 is getting better, it’s that influenza is getting worse,” she said.

Several factors may be contributing to the intensity of this year’s flu season:

  • Increased social activity: With fewer pandemic-related restrictions, people are gathering more, leading to higher transmission of respiratory viruses.
  • Lower flu vaccination rates: CDC data shows flu vaccination rates have dropped to a three-year low among the general population and a six-year low among children.
  • Reduced immunity: Some experts believe that reduced flu exposure in recent years due to social distancing and masking may have weakened population-wide immunity, making this year’s flu strain hit harder.

While the flu is causing the most concern, other viruses are also circulating at high levels:

  • COVID-19: While hospitalizations are declining in many areas, CDC wastewater data suggests that infections remain high.
  • RSV: Cases are decreasing, but the virus remains a concern, particularly for young children and older adults.
  • Norovirus: The US saw a record number of norovirus outbreaks between November and January. While cases appear to be declining, this highly contagious gastrointestinal virus continues to spread.

Dr. Daniel Griffin, an infectious disease specialist at Columbia University, said that flu is currently the most common illness requiring hospital consultations, but the presence of multiple viruses is creating a “quademic” of respiratory and gastrointestinal infections.

Children have been particularly affected this flu season, with 68 pediatric flu deaths reported so far. Experts worry that this number could rise, as last year’s total reached 200. Some children have developed serious neurological complications due to the flu, highlighting the risks of severe illness in younger populations.

Public health officials urge people to take precautions, including:

  • Getting vaccinated: It’s not too late to receive a flu shot or COVID-19 booster. While this year’s flu vaccine has been less effective (about 35% compared to the typical 45%), it still provides important protection.
  • Practicing good hygiene: Washing hands regularly, covering coughs and sneezes, and staying home when sick can help reduce the spread of illness.
  • Wearing a mask in crowded spaces: Particularly in high-risk settings like hospitals or public transportation, wearing a mask can help prevent respiratory virus transmission.

With input from USA Today and Axios.