Flu activity ramps up again

For the week ending Jan. 24, CDC data shows that positive flu tests were up 18% nationwide compared to the week before. Although the weekly flu hospitalization rate declined from the previous week, the cumulative hospitalization rate reached 59.5 per 100,000 population, the highest cumulative rate since the 2010-2011 flu season.

Nationwide, 29 states reported "high" or "very high" levels of influenza-like illnesses (ILI), 10 states reported "moderate" ILI activity, seven states reported "low" ILI activity, and four states and the District of Columbia reported "minimal" ILI activity.

According to Caitlin Rivers, an epidemiologist from Johns Hopkins University, the United States is currently "seeing a second peak, a second rebound from flu," with most cases "concentrated in school-age children."

"Children and kids are always the first to register new trends," Rivers said. "So I do think that the increase will hit adults as well, but for now, it's really concentrated in kids."

Tyler Evans, an infectious disease specialist and CEO of Wellness Equity Alliance, said that flu cases are "higher, significantly higher, than the last few years." So far this flu season, CDC estimates that there have been at least 20 million flu cases, 270,000 hospitalizations, and 11,000 deaths, including 52 pediatric deaths.

According to Evans, a less effective flu vaccine and declining vaccination rates have likely contributed to the increased spread of cases this flu season. As of Dec. 20, only 42.5% of U.S. children had received a flu vaccine, a record low since 2019. Flu vaccination rates also varied significantly by state, though most reported declines in vaccination rates.

How to protect yourself from the flu

As flu cases rise again, health experts emphasize the importance of vaccination. Although this year's flu vaccine is not as effective as previous years', it can still help protect people from severe illness and death. According to the U.K. Health Security Agency, the 2025-2026 is still 70% to 75% effective for children and 30% to 40% effective for adults.

"That's a heck of a lot better than nothing," Evans said. And if you are infected, being vaccinated "takes it [the flu] from wild to mild."

"It is not too late to get vaccinated, and it definitely does make a difference," he added.

Aside from getting vaccinated, people should avoid those who are coughing and sneezing and practice regular handwashing with soap and water. Certain groups, including older adults, young children, pregnant people, and those with an increased risk of severe illness, may also want to wear a mask to reduce the risk of infection.

"If you're sick, don't be a hero," said George Rust, a professor at Florida State University College of Medicine. "Don't spread your germs." People should avoid going to work or school if they're sick or experiencing symptoms like fever, body aches, and fatigue.