Subclade K has become the dominant form of flu and is slightly different from the virus targeted by this year’s flu vaccine.

That all followed a huge spike in flu activity in New York City, Long Island, and North Jersey in the first week of December.

Flu activity is increasing across the U.S. amid holiday travel and gatherings, according to the latest data from the CDC.

Much of the concern this flu season is coming from the spread of subclade K, a subtype of influenza A. Similar subtypes have ...

The “super flu” is a variant of influenza A H3N2 called subclade K. Historically, similar variants have caused more severe ...

Were you or a loved one sick over the holidays? Here's what to know about new influenza variant and how to stay healthy ...

Current data from the CDC suggests the H3N2 strain and subvariant K - the dominant subvariant in the U.S. - are more ...

This year’s influenza virus has been dubbed the “super flu” for how quickly it’s spreading — and how hard it’s hitting. In ...

At least 14 states and Washington, DC, are seeing high and very high levels of flu, mainly caused by a surprise new influenza ...

The numbers are especially grim in the Big Apple: According to preliminary hospital data collected by New York City’s ...

Flu season has hit early and hard in the East, with New York experiencing a record number of cases of the viral respiratory illness. The state’s health department reported that 71,123 influenza cases ...

The flu season is off to an active start, and cases are likely to surge higher after the holiday season. Just a third of ...