It’s not shocking to see cases of the flu jump up during respiratory virus season. But there’s been enough talk about the so-called “super flu” swirling around that it’s fair to wonder what’s going on out there.

“Flu has really taken off in the last week in this country,” William Schaffner, MD, an infectious disease specialist and professor at the Vanderbilt University School of Medicine, tells SELF. While Dr. Schaffner stresses that “the flu is the flu,” there are a few explanations for why symptoms may be a little more intense right now. Here’s what you need to know about this year’s flu symptoms, plus what to do next.

Flu cases are being driven by a new variant.

It’s called subclade K, and it’s a version of influenza A H3N2. It’s important to point out that influenza A H3N2 isn’t new, but subclade K is. This variant of the flu has new mutations that make it more infectious than other strains that have been circulating lately, leading some to call it “super flu.” In fact, influenza A H3N2 mutated seven times over the summer, to emerge as a stronger, heartier virus, Thomas Russo, MD, professor and chief of infectious disease at the University at Buffalo in New York, tells SELF.

Unfortunately, those mutations have made this flu strain better at evading previous immunity you might have, either from being vaccinated or having had other versions of the flu in the past, Dr. Russo says.

Subclade K hit the UK first, and details of the country don’t paint a pretty picture. Early data from the British government suggests that the flu vaccine is 30% to 40% effective at preventing emergency room visits from the flu in adults, while it’s up to 70% effective at keeping kids out of the ER. Essentially, this strain of the flu is highly infectious and our usual tools at preventing it aren’t as effective as we’d like.

The latest data from the Centers for Disease Control and Prevention (CDC) show that nearly all stats on the flu are jumping up across the country.

Symptoms are the same, but may be more intense.

Both doctors stress that this is still the flu. “It’s not like this is a new flu,” Dr. Russo says. With that, you can expect the standard symptoms. According to the CDC, those include: