How bad is flu in your state? What to know as new variant spreads

Flu season has taken off across the country, with cases rising rapidly in some parts of the country in recent weeks.

“We’ve seen sustained, high activity across several key indicators in many parts of the country,” said Alicia Budd, head of the Centers for Disease Control and Prevention’s national influenza surveillance team.

The CDC released its latest flu report Friday, estimating that so far this season there have been at least 4.6 million illnesses, causing more than 49,000 hospitalizations and 1,900 deaths.

So far, young children, from infants to age 4, have been hardest hit.

There is plenty of other evidence of an early and aggressive flu season.

From November to December, concentrations of influenza A virus in wastewater increased 390% nationwide, according to data from WastewaterSCAN, an academic program of Stanford University in partnership with Emory University.

The upward trend is increasing “very steadily,” said Marlene Wolfe, director of the WastewaterSCAN program and assistant professor of environmental health at Emory. “We don’t see any signs of stabilization yet.”

Dr. Chase Shutak, medical director at Children’s Minnesota, said positive flu cases at the facility have doubled in the past week.

The symptoms are varied.

“Some years, all the kids who come down with the flu just have that classic flu appearance. They look a little dazed. They’re unhappy. They have a glazed look in their eyes,” he said. Additionally, this year, he added, there are a good number of children who have milder symptoms but “annoying enough that they keep coming.”

Influenza A, more precisely H3N2, is currently the dominant strain. Although anyone of any age can be affected, H3N2 tends to cause more hospitalizations and deaths in older people.

There is concern that children who are currently sick with the flu could spread it to their grandparents and other elderly people during the holidays.

“With school holidays lasting a few weeks and family gatherings, it is quite possible that some of the existing mix of viruses among school groups will spill over into a different population,” Budd said.

Where does the flu spread?

Influenza activity is high or very high in 14 states, including Colorado, Idaho, Louisiana, Michigan, New Jersey and South Carolina, as well as New York City; Washington, DC; and Puerto Rico, according to the CDC report.

However, the flu does not have to be widespread to be fatal. While the latest CDC report shows “minimal” flu activity in Wisconsin, for example, state health officials reported Thursday that one child in the state had died from the flu.

The North Carolina Department of Health and Human Services reported its first pediatric flu death of the season on Wednesday.

These cases are likely not counted among the CDC’s latest report of three pediatric flu deaths so far this year because the data is current through Dec. 13. The CDC’s next flu update will be released on December 30.

The 2024-2025 flu season was particularly deadly, especially for children. According to the latest data, 288 children have died from the flu, matching a record set during the 2009-2010 H1N1 pandemic.

A CDC report released in September found that half of the children who died from the flu last year were otherwise healthy. About 89% had not received the flu vaccine.

Will the flu vaccine work this year?

The annual flu vaccine is notoriously imperfect when it comes to exactly matching the flu strains that are circulating. This year, a strain called subclade K H3N2 emerged, making changes to the virus’s surface protein.

The surface protein is important because it is what the body looks for to know if it has seen the virus before. If the protein looks slightly different, the body might not be able to fight it off as well.

Budd said it’s difficult to predict how well this vaccine will ultimately work. Even if the strain has “drifted” somewhat, vaccines generally contain protection against the H3N2 virus.

“We’ve had past seasons where there were what we call drift viruses, which is how we would categorize this K subclade,” she said. “In some of these cases, there have been impacts on the effectiveness of the vaccine, but there have also been seasons of derived strains where we have seen the vaccine continue to provide protection.”

Budd said it’s important for everyone, including children, to get the flu vaccine.

“It is still the primary preventive measure against influenza, a serious illness, and we absolutely continue to recommend it this year, even in light of strain drift,” she said.

Demand for Tamiflu, an antiviral used to treat the flu, is slightly higher than it was this time last year, according to GoodRx.

People typically only get prescription antivirals when they’re sick enough to go to the doctor, not just because they tested positive for the flu, said Tori Marsh, senior director of research for GoodRx.

“What stands out this season is how early use of Tamiflu is increasing,” she said. “When we see that prescription antiviral use increases earlier than average, this often indicates that influenza activity is developing earlier and may last longer.”