Let's start with some of the things we know about the new COVID variant, Omicron, which

was first reported to the World Health Organization five days ago.

The South African authorities reported that they were seeing a large number of cases of

a variant with a very large number of mutations, way beyond what you would expect.

This is Bill Hanage.

He's an associate professor of epidemiology.

He's at Harvard's TH Chan School of Public Health.

They had reason to think from a particular set of test results that this had not spread

just in one small location, but which was in several regions around the country.

And they were right.

Because shortly after that, we heard about confirmed cases in places like Hong Kong and

Belgium.

And basically things have been moving very quickly since then, and we're still scrambling,

trying to figure out exactly what sort of beast we're dealing with.

Those mutations, Hanage mentioned, they're the reason this particular variant is raising

alarm bells.

Omicron has more mutations than any strain detected before it, which means it could be

the most contagious variant yet.

It just kind of exploded.

That's Dr. Anthony Fauci speaking to NBC.

When you look in South Africa, you were having a low level of infection, and then all of

a sudden there was this big spike.

...