Medical Minute: Scientists Studying New Omicron Sub-Variant Called BA.2

As a new version of the Omicron variant, known as BA.2, quickly spreads around the world, scientists are worried it could be more contagious and perhaps harder to detect. 

But CBS News' medical contributor Dr. David Agus said the newly detected COVID-19 strain is actually comparable to Delta when it comes to detection. He also urged people to get vaccinated, noting that booster shots offer strong protection against the new subvariant. 

In Denmark, one of many countries that are "weeks ahead" of the U.S. in dealing with Omicron, BA.2 was found to be 50% more infectious, Agus said Monday on "CBS Mornings." 

"But with the booster, you have significant protection against BA.2. That's what people really care about," he said.

Some have called this version of the coronavirus stealthier than the original Omicron because genetic traits make it appear slightly different in testing — but Agus disagreed. 

"It's really not stealth," he said. "What it means is that Omicron has two different sisters, if you will, BA.1 and BA.2. BA.1 is the one that had been dominating in the United States. When you looked at the PCR [test], [BA.1] looked differently than Delta did.

"BA.2 looks exactly the same as Delta, so it's just as easy to detect. It just looks like Delta on PCR," he said. 

The new Omicron variant has been detected in at least 40 countries, including the U.S. Agus said BA.2 would likely slow an expected decline in infections, but he believes there's an end in sight.

"When you're exposed to BA.1 — the first Omicron, if you will — you will have immunity, hopefully, that will cross over to BA.2," he said. "And since so many people have been exposed, I think we're going to see a decline." 

Agus previously said the country would see a significant decline in cases by mid-February. But with BA.2, it will probably take a little longer, he said.

"But we are going to be in a much better situation come spring," Agus said. "So I think toward the end of February and March, we'll have significantly lower numbers of cases in this country."

He also expressed hope that the Food and Drug Administration will soon authorize a coronavirus vaccine for children under 5 years old. 

"They should have a vaccine, we hope, in March, as long as the FDA accepts the two-shot data and is not pushing for the three-shot," he said. 

Until then, Agus said, it's crucial to protect that part of the population. 

"When you go out, you want to make sure that that young child can wear a mask if they can," Agus said. "And then, who they interact with is really critical. The people they interact with, they have to wear a mask. 

"So, as much as possible, protect them," he said. "There's hope around the corner. We will have that vaccine for that age group, and they will have protection hopefully soon."