This is an historic time.

This is going to be a multi-year fight.

Why is it taking so long to get a screening test?

It is not a hoax, it is real.

Something that we have never experienced before.

Wash hands, wash hands, wash hands.

I mean you're the scientist, you're gonna have to tell me.

Welcome, welcome to Science Rules, coronavirus edition.

I'm your host Bill Nye, and this is the series

that brings you the latest analysis and the science of this pandemic.

So that you'll be informed, prepared, and come.

We're all in this together, my friends,

with a continuing rollout of vaccines around the world.

It sure seems like we're nearing the end of the worst of it,

at least when it comes to the severe cases.

But just last week, as that he came out looking at the plate of COVID long haulers.

People experiencing something called brain fog.

Could this be the beginning of a whole new phase of COVID-19,

a drawn out error of persistent symptoms?

I'd here to help us understand this phenomenon.

Is Dr. Igor Koralnik.

He's a neurologist at Northwestern University

...