A second version of omicron is spreading. Here's why scientists are on alert

A computer-generated image of a coronaviruses.

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As the omicron surge begins to diminish in parts of the U.S., scientists are watching for another coronaviruses variant that is spreading rapidly in parts of Asia and Europe. Scientists detected cases of it in several U.S. states, including California, Texas and Washington.

Scientists think that BA.2 will spread in the US over the next month. There is growing evidence that it is just as infectious as the first omicron variant.

It could be that BA.2 has a small advantage, according to an epidemiologist at the University of Bern who has been tracking variant all around the world through the Nextstrain project.

Will that small difference be enough to keep the surge going in the U.S., as it has inDenmark?

What is omicron BA.2?

You can see that BA.2 is a sibling of BA.1. They have a lot of the same genes, but also have a lot of different ones.

She says that they are very much like siblings. It was different but related.

When scientists discovered omicron in South Africa and Botswana, they did not find just one version. They found three of them, called BA.1, BA.2 and BA.3 at the University of Edinburgh.

The first one, BA.1, took off quickly and spread around the world. It looked like BA.2 and BA.3 were weaker than BA.1.

We thought that BA.2 was not as fit as BA.1, and it would end up petering out.

That is not what happened.

Is omicron BA.2 as transmissible as omicron BA.1?

Scientists have begun to be surprised by omicron BA.2 over the past few weeks. It looks like it can out compete its sibling omicron BA.1 in some countries.

In December of last year, omicron BA.1 caused a huge surge in cases in the country. As cases began to decline, BA.2 began to spread very quickly. After only a few weeks, BA.2 took over the outbreak and has lengthened the surge. More than 40,000 cases are recorded each day in Denmark. In the second week of January, more than 50% of the cases were caused by BA.2.

People queue for rapid coronaviruses tests at a center set up at a church in Aalborg,Denmark, where a second omicron variant has fueled a surge.

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In England and Germany, Omicron BA.2 is causing at least 5% of cases. Surges could be extended in those locations as well as in the United States.

The data shows that BA.2 is stronger than BA.1 and may be more contagious.

Is BA.2 more dangerous than BA.1?

Many studies show that infections with omicron BA.1 have a reduced risk of severe disease.

The University of California San Francisco's Dr. Peter Chin-Hong says that preliminary evidence shows that this will be the case with omicron BA.2.

There was no increased risk of going to the hospital if you have BA.2 compared to if you have BA.1, according to Chin-Hong.

There is cautious optimism about inoculations. The data from the U.K. government shows that a third shot of the vaccine protects against both infections. In both cases, it reduces the risk of a disease. There are many similarities between BA.1 and BA.2 and the part of the virus that many antibodies target.

Chin-Hong thinks the vaccines will provide excellent protection against disease.

I have no guarantee that you won't get sick if you have already had COVID-19, but I feel very confident that you will.

Chin-Hong says that this distinction is crucial for the future of COVID-19. He says that communities need to shift their focus from stopping all infections to keeping everyone safe from serious disease and hospitalization.