Tennessee sees surge in flu cases

Tennessee is part of a national surge in flu cases this winter, many of them attributed to the so-called "super flu."

Threat level: The latest CDC data shows Tennessee and several neighboring states at the highest level of flu activity.

By the numbers: The latest available state data, from Dec. 14-20, shows 6.5% of outpatient clinic visits in Tennessee were tied to flu-like symptoms compared to 3% the week before.

Between the lines: Experts have been specifically worried that the current flu vaccine doesn't cover the fast-spreading strain of the virus known as subclade K.

Yes, but: It's fairly common for vaccines to have mismatches compared to the dominant strain.

• There is data from U.K. health officials suggesting there is some vaccine effectiveness against other strains.

What they're saying: Andrew Pekosz, a virologist at Johns Hopkins University, recommends getting a flu shot for those who haven't.

• It takes around 10–14 days from getting the vaccine to build an immune response, which helps fight infection or reduce disease severity.
• It will protect well against the H1N1 and H3N2 strains while giving "some protection against severe disease from [subclade] K."

Read the national story for more details about the new flu strain