A new form of the flu, which is highly contagious and aggressive, is sweeping the nation this season.

A mutation of influenza A H3N2, called subclade K, has been detected as the culprit in rising global cases, including in the U.S.

The World Health Organization stated on its website that the K variant marks “a notable evolution in influenza A (H3N2) viruses,” which some say calls into question the effectiveness of this season’s influenza vaccine against the strain.

‘AGGRESSIVE’ NEW FLU VARIANT SWEEPS GLOBE AS DOCTORS WARN OF SEVERE SYMPTOMS

The K variant causes more intense flu symptoms, including fever, chills, headache, fatigue, cough, sore throat and runny nose, according to experts.

Among 216 influenza A(H3N2) viruses collected since Sept. 28, 89.8% belonged to subclade K, a CDC report states.

The agency continues to release a weekly influenza surveillance report, tracking which states are seeing the most activity for outpatient respiratory illness.

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Below are the states and regions within the highest range of reported medical visits, not necessarily confirmed influenza cases, as of the week ending Dec. 13.

Very High (Level 1)

Very High (Level 2)

Very High (Level 3)

• New Jersey
• Rhode Island
• Louisiana
• Colorado

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High (Level 1)

• Massachusetts
• Connecticut
• Michigan
• Idaho
• South Carolina

High (Level 2)

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High (Level 3)

• Washington, D.C.
• Maryland
• North Carolina
• Georgia

The CDC has estimated that there have been at least 4.6 million illnesses, 49,000 hospitalizations and 1,900 flu deaths this season so far. The flu vaccine is recommended as the best line of defense against the virus.

In an interview with Fox News Digital, Dr. Neil Maniar, professor of public health practice at Boston’s Northeastern University, shared details on the early severity of this emerging flu strain.

“It’s becoming evident that this is a pretty severe variant of the flu,” he said. “Certainly, in other parts of the world where this variant has been prevalent, it’s caused some severe illness, and we’re seeing an aggressive flu season already.”

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Subclade K is the “perfect storm” for an aggressive flu season, Maniar suggested, as vaccination rates overall are down, and it’s uncertain whether this year’s flu vaccine directly addresses this specific mutation.

“The vaccine is very important to get, but because it’s not perfectly aligned with this variant, I think that’s also contributing to some degree to the severity of cases we’re seeing,” he said. “We’re going in [to this flu season] with lower vaccination rates and a variant that in itself seems to be more aggressive.”

Maniar stressed that it’s not too late to get the flu vaccine, as peak flu season has not yet arrived.

“The vaccine still provides protection against serious illness resulting from the subclade K variant that seems to be going around,” he said. “There are likely to be lots of indoor gatherings and other events that create risk of exposure, so protection is important.”

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Even healthy individuals can become seriously ill from the flu, Maniar noted, “so a vaccine is beneficial for almost everyone.”

“Individuals typically start to develop some degree of protection within a few days and gain the full benefit within about two weeks, so now is the time for anyone who hasn’t gotten the vaccine yet.”

Former U.S. Sen. Ben Sasse of Nebraska announced this week that he has been diagnosed with metastatic stage 4 pancreatic cancer, calling the disease “a death sentence” in a message posted on X.

Sasse, 53, said the cancer has spread and acknowledged that he has “less time than I’d prefer,” although he also mentioned recent scientific advances and his intention to pursue treatment.

“I’m not going down without a fight,” Sasse said when revealing his diagnosis. “One sub-part of God’s grace is found in the jaw-dropping advances science has made the past few years in immunotherapy and more.”

HIDDEN FACTOR IN CANCER TREATMENT TIMING MAY AFFECT SURVIVAL, RESEARCHERS SAY

Pancreatic cancer is known to be one of the deadliest forms of cancer, with ongoing research efforts aiming to improve outcomes. 

Below are six key things to know about the disease.

No. 1: Pancreatic cancer is often diagnosed late and is highly deadly

Pancreatic cancer is notoriously aggressive and difficult to treat, according to the American Cancer Society. Most patients are not diagnosed until the disease has already spread to other organs, largely because there aren’t reliable screening tests and early symptoms can be vague or absent.

The ACS estimates that 67,440 Americans will be diagnosed with pancreatic cancer in 2025, and about 51,980 are expected to die from it. The tumor’s biology creates physical and chemical barriers that reduce the effectiveness of many traditional treatments.

No. 2: New immunotherapies are showing early promise

Researchers at UCLA recently reported progress on an experimental, off-the-shelf, cell-based immunotherapy designed to attack pancreatic cancer.

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In mouse studies, the therapy slowed tumor growth, extended survival and remained effective even after the cancer had spread to other organs, such as the liver and lungs. 

The treatment uses special immune cells called natural killer T (NKT) cells, which are genetically modified so they can specifically recognize and attack pancreatic cancer cells.

Unlike personalized therapies, the NKT cells are naturally compatible with different immune systems and can be mass-produced from donor stem cells. 

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Researchers estimate that one donor could supply cells for thousands of treatments, with a potential cost of around $5,000 per dose. All testing so far has been done in mice, and human trials have not yet begun.

No. 3: Diet and gut health may affect treatment recovery

Separate research from the Massachusetts Institute of Technology has suggested that the amino acid cysteine could help the gut heal after cancer treatments, such as chemotherapy and radiation. 

In mouse studies, cysteine — found in foods like meat, eggs, dairy products, legumes and nuts — helped to regenerate intestinal stem cells that are often damaged during cancer therapy.

Additional unpublished research showed benefits after treatment with 5-fluorouracil, a chemotherapy drug used for colon and pancreatic cancers. 

Researchers emphasized that human studies are still needed and that cysteine is not a cure for cancer itself.

No. 4: Alcohol and lifestyle factors may raise cancer risk

Recent research published in PLOS Medicine by the International Agency for Research on Cancer found that alcohol consumption is associated with an increased risk of pancreatic cancer.

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The study followed 2.5 million people for about 16 years, finding that each additional 10 grams of ethanol consumed per day was linked to a 3% increase in risk. Higher intake levels were associated with greater risk, particularly with beer and spirits.

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Researchers noted that the study was observational and that more work is needed to understand lifetime drinking patterns.

No. 5: Symptoms are often subtle and easily missed

When symptoms do occur, they can include abdominal pain that spreads to the sides or back, loss of appetite and unexplained weight loss, according to Mayo Clinic.

Some patients develop jaundice — yellowing of the skin and whites of the eyes — along with light-colored or floating stools, dark urine and itching. 

Other possible signs include a new diagnosis of diabetes (or diabetes that becomes harder to control), pain and swelling in an arm or leg that may be linked to a blood clot, and persistent tiredness or weakness.

Those who are experiencing symptoms should consult with a healthcare professional.

No. 6: Age, genetics and health conditions can raise risk

Pancreatic cancer risk is influenced by a combination of genetic, medical and lifestyle factors. 

The disease becomes more likely with age, and men are slightly more susceptible, according to the ACS. Those with a family history or inherited genetic mutation also have a higher risk, as do people with type 2 diabetes, obesity and lack of physical activity.

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Diets high in processed or red meats and low in fruits and vegetables, as well as high alcohol consumption, may also contribute to pancreatic cancer risk, along with some occupational chemical exposures, per multiple cancer agencies.

Experts note, however, that many people are diagnosed with the disease despite having no clear risk factors.

Deirdre Bardolf, Ashley J. DiMella, Alex Nitzberg and Angelica Stabile, all of Fox News Digital, contributed reporting.

The first oral GLP-1 medication for weight loss has been approved for use in the U.S.

The Wegovy pill, from drugmaker Novo Nordisk, was cleared by the Food and Drug Administration to reduce excess body weight, maintain long-term weight reduction and lower the risk of major cardiovascular events.

Approval of the once-daily 25mg semaglutide pill was based on the results of two clinical trials — the OASIS trial program and the SELECT trial.

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The Wegovy pill demonstrated a mean weight loss of 16.6% in the OASIS 4 trial among adults who were obese or overweight and had one or more comorbidities (other medical conditions), according to a press release. In the same trial, one in three participants experienced 20% or greater weight loss.

Novo Nordisk reported that the weight loss achieved with the pill is similar to that of injectable Wegovy and has a similar safety profile.

WEIGHT LOSS DRUGS COULD ADD YEARS TO AMERICANS’ LIVES, RESEARCHERS PROJECT

“With today’s approval of the Wegovy pill, patients will have a convenient, once-daily pill that can help them lose as much weight as the original Wegovy injection,” said Mike Doustdar, president and CEO of Novo Nordisk, in the press release.

“As the first oral GLP-1 treatment for people living with overweight or obesity, the Wegovy pill provides patients with a new, convenient treatment option that can help patients start or continue their weight-loss journey.”

POPULAR WEIGHT-LOSS DRUGS COULD TAKE THE EDGE OFF YOUR ALCOHOL BUZZ, STUDY FINDS

The oral GLP-1 is expected to launch in the U.S. in early January 2026. Novo Nordisk has also submitted oral semaglutide for obesity to the European Medicines Agency (EMA) and other regulatory authorities.

Dr. Sue Decotiis, a medical weight-loss doctor in New York City, confirmed in an interview with Fox News Digital that studies show oral Wegovy is comparable to the weekly injectable, just without the needles.

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Although the pill may result in better compliance and ease of use, Decotiis warned that some patients may not absorb the medication through the gastrointestinal tract as well as with the injectable version due to individual idiosyncrasies in the body.

“Most side effects will be GI-related and should be similar to the injectable, such as nausea, vomiting and constipation,” she said.

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“In my practice, I have found tirzepatide (Mounjaro and Zepbound) to yield more weight loss and fat loss than semaglutide by about 20%,” the doctor added. “This has been shown in studies, often [with] fewer side effects.”

More oral GLP-1s may be coming in 2026, according to Decotiis, including an Orforglipron application by Lilly and a new combination Novo Nordisk drug, which is pending approval later next year.

“There will be more new drugs available in the future that will be more effective for patients who are more insulin-resistant and have not responded as well to semaglutide and/or tirzepatide,” the doctor said. “This is great news, as novel drugs affecting more receptors mean better long-term results in more patients.”

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As these medications become cheaper and easier to access, Decotiis emphasized that keeping up with healthy lifestyle habits — including proper nutrition with sufficient protein and fiber, as well as increased hydration — is essential to ensuring lasting results.

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“If not, patients will regain weight and could lose muscle and not enough body fat,” she said.

Fox News Digital reached out to Novo Nordisk for comment.