CEDAR SPRINGS, Mich. — A new influenza virus mutation is spreading across the United States, increasingly infecting Americans. It is a strain of influenza A called “H3N2 subclade K,” according to the Centers for Disease Control and Prevention (CDC). It was identified in August 2025.
In a CDC study since Sept. 28, 2025, 86.8% of viruses collected belonged to H3N2 subclade K.
“Flu activity is on the uptick,” said Amy Shears, immunization program supervisor for Kent County. “We’re seeing that across the whole state of Michigan and here in Kent County.”…