It’s still not too late to get a flu shot.

Flu is everywhere in America right now. If you’re not sick, there’s a good chance some of your friends, family members, or colleagues are.

Just look at how 2017 compares to the past two years in this GIF showing levels of flu activity — from sporadic to widespread — in the last week of December:

 Javier Zarracina/Vox
Flu activity at the end of December, in 2015, 2016, and 2017.

“This is the first year we’ve had the entire continental US be the same color on the [map],” Dan Jernigan, head of the CDC’s flu division, summed up today in a press briefing.

The season started early, and while we seem to be at peak flu right now, public health officials anticipate flu viruses will circulate for a few more moths — bringing with them a lot of illness, hospitalizations, and even death.

Around the country, there are already reports of doctors’ offices bursting at the seams with flu patients, and Alabama just declared a public health emergency over the flu. So why is this year’s flu season so wretched? And what can you do about it? Here’s what you need to know.

Why this flu season is so bad

Flu is a viral respiratory disease, and it leads to nasty fevers, headaches, coughs, muscle pains, and runny noses that make many people miserable in the fall and winter.

There are four species of influenza — A, B, C, and D — and seasonal flu is caused by influenza A and B viruses. Every year, different strains of these viruses circulate. The reason this year’s flu season is more severe and widespread is because it involves the dreaded H3N2, a strain of Read More Here