As winter tightens its grip across the United States, the 2025-2026 flu season has emerged as one of the most severe in decades, putting immense pressure on hospitals and families alike. According to the U.S. Centers for Disease Control and Prevention (CDC), at least 45 states reported "high" or "very high" influenza activity for the week ending December 27, 2025—a level not seen since the 1997-1998 season. In New Jersey, reported flu cases at the end of December more than doubled compared to the same time last year, a trend echoed nationwide as the number of doctor visits for flu-like symptoms soared to 8.2% of all outpatient appointments (CDC data cited by TODAY.com).
This year’s flu surge is fueled by a new variant, the influenza A H3N2 subclade K—nicknamed the "super flu." This strain, which accounts for about 90% of cases, carries seven new mutations. While experts like Dr. Scott Roberts of Yale School of Medicine stress that there’s "no indication this is a more severe strain," they note that the mutations make it slightly less recognizable to immune systems primed by previous infections or vaccinations. "There's increased numbers of people getting infected than previous years," Roberts told TODAY.com, and the numbers are staggering: over 11 million illnesses, 120,000 hospitalizations, and 5,000 deaths, including nine children, have been attributed to the flu so far this season, per CDC estimates.
Hospitals from New York City to North Carolina are feeling the strain. In New York, emergency rooms are "packed," with flu-related hospitalizations reaching record highs, according to Dr. Michael Phillips of NYU Langone Health. "New York was hit hard and hit early. Our emergency departments are packed," Phillips said. Connecticut, South Carolina, and North Carolina have also reported overwhelmed facilities, with some hospitals restricting visitors to manage the influx of flu patients. North Carolina saw the first pediatric flu death of the season, and Dr. Daniel Park of UNC Children’s emergency department described the situation bluntly: "Our children's hospital is bursting at the seams. We're at capacity."
Flu symptoms this season remain familiar—fever, chills, extreme fatigue, body aches, sore throat, cough, and stuffy or runny nose—but doctors have noted a rise in gastrointestinal complaints such as vomiting and diarrhea. "The flu will make you feel like you’ve been hit by a truck," Dr. Linda Yancey of Memorial Hermann Houston told TODAY.com. Symptoms often begin suddenly and can last from a few days up to two weeks, though most people recover on their own. Antiviral medications, if taken early, can help lessen symptom severity and duration, said Phillips, but they require a prescription and are most effective when started promptly.
Testing for flu is crucial, especially in a season where other viruses are also circulating. Nucleic acid amplification tests, like PCR, are considered the gold standard for distinguishing flu from similar illnesses such as COVID-19 and respiratory syncytial virus (RSV). At-home flu tests are available, though their accuracy ranges from 50% to 80% in children and is lower in adults. Dr. Park advises those with mild symptoms to stay home and use rapid tests rather than crowding emergency rooms for a diagnosis.
Other illnesses are also contributing to the winter surge. Norovirus, a contagious stomach bug causing vomiting and diarrhea, can keep individuals contagious for up to two weeks after symptoms resolve. RSV, which can be particularly dangerous for infants and the elderly, is usually contagious for three to eight days, but high-risk individuals may spread it for up to four weeks. COVID-19 continues to circulate, with symptoms ranging from mild to severe and sometimes including loss of taste or smell. The CDC recommends isolating for five days after testing positive for COVID.
Flu transmission is primarily via tiny droplets released when infected individuals cough, sneeze, or talk, though touching contaminated surfaces can also spread the virus. The CDC emphasizes frequent hand-washing, basic hygiene, and annual vaccination as the best defenses against the flu. This year’s flu vaccine includes three viruses: influenza A H3N2, A H1N1, and influenza B. While the emergence of subclade K created a slight mismatch with the H3N2 component of the vaccine, experts like Roberts point out that it still offers important cross-protection. "The vaccine is still going to offer cross-protection. It just won’t be as robust as what we wanted," he explained. Early data from the UK’s Health Security Agency suggest the 2025-2026 vaccine is about 70-75% effective at reducing hospitalizations among children.
However, a significant change arrived on January 5, 2026: the CDC no longer universally recommends the flu vaccine for children. Instead, it now advises parents to make vaccination decisions in consultation with their healthcare provider—a move the American Academy of Pediatrics called "dangerous." Last season, 89% of the children who died from flu were unvaccinated, according to the CDC. For adults and high-risk groups, including those over 65, children under two, and people with weakened immune systems, vaccination remains strongly advised.
Preventive measures extend beyond vaccination. The CDC and infectious disease experts recommend testing when symptomatic, staying home when ill, avoiding contact with sick individuals, wearing masks in high-risk environments, frequent hand-washing, disinfecting surfaces, and practicing social distancing when possible. These steps, familiar from the pandemic, are still considered the best tools for reducing the spread of not just flu, but also COVID-19, RSV, and norovirus.
As the season continues—likely into March or April, say experts—hospitals brace for more cases and potential complications. Dr. Phillips warns, "A lot of the mortality from flu isn’t directly from influenza. It’s from secondary bacterial infections, which tend to present 10 days or so after influenza infection." With hospitals already stretched, any additional surge could put further strain on the healthcare system.
For now, the message from public health officials is clear: it’s not too late to get vaccinated, and basic preventive measures matter more than ever. As Dr. Roberts summed up, "Flu season extends until March or April, so there’s a lot of time to benefit from immunity." With vigilance and collective action, communities can weather this historic flu season—and perhaps come out a little wiser for the next one.