LANSING, Mich. (WOWO) — Michigan is facing a severe flu season fueled by a new H3N2 subclade K strain, also known as the “super flu,” resulting in a sharp rise in hospitalizations statewide. As of Monday, 818 patients are hospitalized with influenza, including 759 adults and 59 children. Additionally, 540 patients have tested positive for COVID, according to the Michigan Health & Hospital Association.

The majority of flu hospitalizations are adults 75 and older, but very young children, ages 4 and under, make up the next-highest group, health officials report. Hospitals are also treating thousands of additional patients with flu, COVID, and other respiratory illnesses according to Bridge Michigan.

Experts describe a “layer cake effect,” where multiple respiratory viruses — including strep throat and rhinovirus — combine to strain medical facilities. Alan Ayers, president of Urgent Care Consultants, notes that the spike in Flu A cases suggests the virus is highly contagious and spreading quickly following the holidays.

The current flu surge is likely exacerbated by subclade K’s evolution, which emerged after the U.S. had settled on the 2025-26 vaccine formula. While vaccines may not completely prevent infection, health professionals say they reduce symptom severity.

Vaccination rates remain low: fewer than one in four Michiganders are vaccinated against the flu, and fewer than one in ten against COVID. Dr. Terry Matthews, CEO of Lansing Urgent Care, says unvaccinated patients are the most severely affected, often resulting in missed work and school for children.

The Michigan Department of Health and Human Services, along with medical groups, recommend vaccination against influenza, COVID, and RSV to reduce severe illness and hospitalizations. Residents can find vaccination locations through local health departments or the Vaccine Finder website.