A new COVID variant has arrived in the United States.What you need to know about the “stealth” version of Omicron BA.2.


Scientists and health officials around the world are keeping an eye on the progeny of the Omicron variant found in at least 40 countries, including the United States.

This version of the coronavirus, which scientists call BA.2, is widely believed to be more stealth than the original version of Omicron because certain genetic characteristics make it somewhat difficult to detect. Some scientists are worried that it could be more contagious.

But they say there’s still a lot we don’t know about it, such as whether it better avoids the vaccine or causes a more serious illness.

Where does BA.2 spread?

Since mid-November, approximately 15,000 BA.2 gene sequences have been uploaded to GISAID, a global platform for sharing coronavirus data, in more than 30 countries.As of Tuesday morning, 96 of these sequenced cases came from the United States

Dr. Wesley Long, a pathologist at the Houston Methodist, Texas, said he had identified three cases of BA.2.

Mutants look much more common in Asia and Europe. According to the Statens Serum Institut, which is under the jurisdiction of the Danish Ministry of Health, Denmark accounted for 45% of all COVID-19 cases in mid-January, up from 20% two weeks ago.

What do you know about BA.2.

COVID-19 Nasal swab test.

COVID-19 Nasal swab test.

There are many mutations in BA.2. About 20 peplomers studded on the outside of the virus are shared with the original Omicron. However, it also has additional genetic changes not seen in the early versions.

Dr. Jeremy Luban, a virologist at the University of Massachusetts School of Medicine, said it is unclear how important these mutations are, especially in the population that encountered the original Omicron.

For now, the original versions known as BA.1 and BA.2 are considered a subset of Omicron. However, if it is considered a globally significant “variant of concern”, global health leaders can give it its own Greek alphabetic name.

The rapid spread of BA.2 in several places raises concerns that it may take off.

“There are some signs that it may be as contagious as (original) Omicron, or perhaps slightly more contagious, as it may compete in some areas,” Long said. I am saying. “But I don’t always know why.”

Initial analysis by Danish scientists shows that hospitalization for BA.2 is no different than the original Omicron. Scientists there are still investigating the infectivity of this version and how well current vaccines work against it. Also, it is unclear how well the treatment works for it.

Doctors also do not yet know for sure if anyone who already has COVID-19 caused by Omicron could get sick again with BA.2. However, they hope that previous Omicron infections may reduce the severity of the disease, especially if someone later becomes infected with BA.2.

Dr. Daniel says that the two versions of Omicron have enough in common that infection with the original mutant may “provide cross-protection against BA.2.”

Kritsukes, an infectious disease specialist at Brigham and Women’s Hospital.

Scientists will be conducting tests to see if antibodies from the original Omicron infection “neutralize BA.2 in the laboratory and can be inferred from it.”

How concerned are health agencies?

The World Health Organization classifies Omicron as a whole as a variant of concern. This is the most serious name for a coronavirus variant, but it does not identify BA.2 with its own name. However, given the increase in some countries, authorities say the BA.2 investigation should be “priority”.

Meanwhile, the UK Health and Safety Agency has designated BA.2 as a “variant under investigation”. It cites an increasing number in the UK and internationally.Still, the original version of Omicron remains dominant in the UK

Why is it difficult to detect?

Because the original version of Omicron had specific genetic characteristics and was known as “S gene targeting disorder,” health officials were able to quickly distinguish it from delta using specific PCR tests. ..

BA.2 does not have the same genetic habits. Therefore, in testing, BA.2 looks like a delta, Long said.

“It’s not that the test doesn’t detect it; it just doesn’t look like Omicron,” he said. “Don’t get the impression that’Stealth Omicron’means we can’t detect it. All our PCR tests can still detect it.”

What do you do to protect yourself?

Your doctor will advise you on the same precautions as before. Vaccine and follow public health guidance on wearing masks, avoiding crowds, and staying home in case of illness.

“Vaccines still provide excellent protection against serious illness, hospitalization and death,” Long said. “Whether you’ve been infected with COVID 19 before or you’ve been naturally infected, your vaccine protection is even stronger, lasting, and in fact … for those who have been infected before. It works well.”

The latest version reminds us that the pandemic isn’t over.

“We all want it to be over, but until we vaccinate the world, there is a risk of new variants emerging,” Long said.

Contributed by: AP Science Writer, Laura Ungar

This article was originally published in Rochester Democrat and Chronicle. BA.2 Variant: What You Need to Know About the “Stealth” Version of Omicron