Flu season has begun across the country, and cases have increased rapidly in some parts of the country over the past few weeks.
“We are seeing sustained, elevated activity across multiple key indicators in many areas of the country,” said Alicia Budd, head of the Centers for Disease Control and Prevention's internal influenza surveillance team.
CDC published its latest flu report on FridayThere are an estimated at least 4.6 million illnesses this season, resulting in more than 49,000 hospitalizations and 1,900 deaths.
Young children, from infants to 4 years old, have been hit the hardest so far.
There is plenty of other evidence of an early and aggressive flu season.
According to WastewaterSCANacademic program at Stanford University in partnership with Emory University.
The upward trend is “very consistent,” said Marlene Wolfe, director of the WastewaterSCAN program and assistant professor of environmental health at Emory. “We don’t see any signs of plateauing yet.”
Dr. Chase Shutak, medical director at Children's Minnesota, said the number of positive flu cases at the facility has doubled in the past week.
The symptoms varied.
“Some years, every kid who gets the flu has the classic flu look. They look a little dazed. They're miserable. Their eyes are glazed over,” he said. In addition, he said, there are a fair number of children this year with milder symptoms but “so annoying that they're still showing up.”
Influenza A, especially H3N2, is currently the dominant strain. Although anyone of any age can become infected, H3N2 tends to cause more hospitalizations and deaths among older people.
There are concerns that children who currently have the flu will spread it to their grandparents and other elderly people during the holidays.
“As schools go on break for a couple of weeks and have family gatherings, it is possible that some of the existing mixing of viruses among school groups will shift to 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; Washington, DC; and Puerto Rico, according to the CDC report.
However, the flu does not have to be widespread to be deadly. While the latest CDC report shows “minimal” flu activity in Wisconsin, for example, State health officials said On Thursday, it was reported that a child in the state had died from the flu.
On Wednesday North Carolina Department of Health and Human Services reported the first childhood flu death of the season.
Those cases are likely not included in the CDC's latest report, which shows three childhood flu deaths this year, because the data is current through Dec. 13. The CDC's next flu update will be released on December 30th.
The 2024-2025 flu season was particularly deadly, especially for children. According to the latest data, 288 children have died from the flu, a record set during the 2009-2010 H1N1 pandemic.
A CDC report published in September found that half of the children who died from the flu last year were otherwise healthy. About 89% did not receive a flu vaccine.
Will the flu shot work this year?
The annual flu shot is notoriously imperfect when it comes to accurately matching circulating flu strains. This year, a strain called subclade K H3N2 emerged that made changes to the surface protein of the virus.
The surface protein is important because it is what the body looks for to determine whether it has seen the virus before. If the protein looks even slightly different, the body may not be able to fight it.
Budd said it's difficult to predict how well this vaccine will ultimately work. Although the strain has drifted a bit, the vaccines generally provide protection against the H3N2 virus.
“We've had seasons where we've seen what we call drifting viruses, and that's how we would classify this subclade K,” she said. “In some of these cases it affected the effectiveness of the vaccine, but there were also seasons with strain drift where we saw the vaccine continue to provide protection.”
Budd said it's important for everyone, including children, to get a flu shot.
“This continues to be the primary preventive measure against influenza, severe illness, and we will definitely continue to recommend it this year, even as the strain spreads,” she said.
Demand for Tamiflu, an antiviral drug used to treat the flu, is slightly higher than last year. According to GoodRx.
People typically get prescription antiviral drugs only when they are sick enough to see a doctor, not just because they test positive for the flu, said Tori Marsh, senior director of research at GoodRx.
“What stands out this season is how early use of Tamiflu is increasing,” she said. “When we see prescription antiviral drug use increase earlier than average, it often indicates that influenza activity is rising earlier and potentially lasting longer.”
