Since October, at least 20 million Americans have gotten the flu, the Centers for Disease Control and Prevention reports. That number includes at least 270,000 flu hospitalizations and 11,000 deaths, including 52 pediatric deaths this flu season.
“That is higher, significantly higher, than the last few years,” says Dr. Tyler B. Evans, an infectious disease specialist and CEO of Wellness Equity Alliance, a public health organization for underserved populations. Currently, the most common flu strain infecting people is a strain of the influenza A (H3N2) virus called “subclade K.” It’s responsible for 90% of infections this flu season, and has been deemed by some media outlets as a “super flu.”
“I wouldn’t call it ‘super flu,’ [but] it is more severe than prior seasons,” Evans says, adding that “severity” in this context typically refers to how contagious it is. Symptomatically, it’s similar to most other flu strains, he notes.
Evans cites two reasons for this year’s increased levels of spread. First: “The vaccine is not quite as effective” as it usually is, he says. To be clear, it’s “still very effective,” says Evans — it just lacks the same degree of prevention as in most years, due to some viral mutations in this year’s predominant influenza strain that vaccine manufacturers didn’t predict.
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The second reason, says Evans: “We are seeing more infections because there’s such a significant reduction in vaccinations.” Approximately 42.5% of children in the U.S. received their flu shot by Dec. 20, a record low since 2019, NBC News reported on Jan. 9. Even with the mutations that altered the current flu strain, the 2025-26 flu vaccine is still 70% to 75% effective for kids, and 30% to 40% effective for adults, the U.K. Health Security Agency estimates.
“That’s a heck of a lot better than nothing,” Evans says.
When people decide against getting a flu shot, they typically see little benefit to the vaccine, says Evans — and vaccine hesitancy is rising more broadly across the United States.
But in terms of infectiousness, the current flu is the most severe since the 2017-2018 season for adults, and the most severe since the 2010-2011 season for kids, says Evans. And the vaccines have been approved as safe by the U.S. Food and Drug Administration, which works with other health agencies and manufacturers on the formulations each year.
Here are a few signs to look out for to distinguish the flu from a cold, and how you can best protect yourself during the rest of a particularly infectious flu season.
A doctor’s tips for protecting yourself and others from the flu
With approximately one more month left in flu season — it typically lessens after February — you should still get a flu shot if you haven’t already, says Evans. That advice is most important for kids, parents, people who live in big cities and anyone living in a multi-generational household or smaller apartment with roommates, he says.
While being vaccinated won’t completely prevent infections, “if you are infected, it takes it from wild to mild,” he says, adding: “It is not too late to get vaccinated, and it definitely does make a difference.”
Whether you’ve gotten a flu shot or not, if you catch yourself experiencing some small symptoms — like a slight sore throat — or you have a sick kid at home, Evans strongly recommends masking and keeping a safe social distance from others when possible to reduce the chances of getting other people sick.
A few groups of people may need to take flu prevention more seriously: Adults age 65 and older, children ages two and younger, pregnant people, and individuals with certain health conditions have an increased risk of severe complications from the illness. If you fall into one of those camps, you may want to wear a mask more frequently — like while traveling, commuting or working in an office, for example.
And no matter who you are, if you find yourself sick, remember that “treatment is available,” says Evans. Instead of trying to muscle through your symptoms with ibuprofen and hot tea, you can call your primary care doctor or visit urgent care to see if they’ll prescribe you Tamiflu or another kind of medication, he suggests.
Always consult with your primary doctor about the best path forward for your individual health.
Keep an eye out for these symptoms when sick
It can be difficult to determine if you’re dealing with a stubborn cold or something more serious like the flu. If you have a combination of the following symptoms, you’re likely experiencing the latter, according to Evans:
FeverCoughIntense body achesFatigue
Body aches are the biggest indication it’s the flu and not a cold, he says.
“If a person is really just on the bed, just cannot get up, just really complaining about body aches, that’s flu,” Evans says. “A cold is getting your fever, your sniffles, your cough, etc. So you can differentiate based upon that.”
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