What is BA.2? Why are you listening to the Omicron subvariant? – NBC Chicago

News about the BA.2 Omicron subvariant continues to grow as variants begin to dominate COVID cases in parts of the United States.

A top Chicago doctor said BA.2 is likely to account for the majority of the city’s cases in the coming days and weeks.

Experts say what happens in the United States in the coming weeks can be important for the United States to follow in the footsteps of Europe.

So what is BA.2, what are the associated symptoms, where are they detected and how contagious are they? The breakdown is as follows.

What is BA.2?

BA.2, also known as “Stealth Omicron”, is considered a subvariant of Omicron.

There are several important mutations in BA.2, but the most important ones occur in pesplomers scattered outside the virus. Although these mutations are shared with the original Omicron, BA.2 also has additional genetic changes not found in early versions.

So far, it has not yet been declared as a variant of concern.

“BA.2 is part of Omicron,” said Dr. Isaac Guinai, medical director of laboratory-based surveillance at the Chicago Public Health Service, Thursday. “Because Omicron is a variant of concern, BA.2 is a variant of concern. Like BA.1, it is a variant of concern.”

But that can change.

“People are very careful looking at whether BA.2 needs to be categorized and monitored individually,” Ghinai said. “But even if it’s a variant of concern, it’s very closely monitored at the local, state, and national levels.”

How contagious is BA.2?

According to some health experts, BA.2 seems to be more contagious than Omicron.

“Peplomer has four unique mutations that are different from BA.1 and different from BA.1. These mutations may promote infectivity to about 30% to 50% higher infectivity. “BA.1 mutants,” said Dr. Gregory Moon, an infectious disease doctor and COVID-19 vaccine coordinator at the Cook County Health Department.

Dr. Anthony Fauci, Chief Medical Advisor of the White House, said BA.2 is about 50% to 60% more infectious than Omicron, but it doesn’t seem to be that serious.

“It enhanced communication,” Fauci said. ABC’s “this week” Sunday. “But when you look at the cases, they don’t seem to be more severe and don’t seem to avoid the immune response from vaccines or previous infections.”

Michael Angalone, an associate professor of infectious disease medicine at Northwestern University, said that increased transmission rates could be particularly strong in close contact with infected people, but it’s still hard to tell. It’s premature.

“We are still trying to figure out why we see this increase in the number of cases in some of these countries in Europe, because the virus can be significantly different,” he said. “So is it more contagious? Will more people get infected from one infected individual? There may be some markers of it.”

What are the symptoms of BA.2.

According to Angalone, the symptoms of BA.2 are similar to those seen in many COVID infections.

“That is, it’s the same virus, and because it’s SARS coronavirus 2, it has the same symptoms,” he said.

Huhn said that Omicron caused more upper respiratory tract symptoms, but it was too early to tell.

“For now, I’m not sure if I know a specific feature that is different between BA.2 and BA.1 That is, for BA.1, it’s not primarily an upper respiratory tract infection, but an upper respiratory tract infection. It was known to be an upper respiratory tract infection that could cause pneumonia and more serious complications. ”

For some people, the coronavirus causes mild or moderate symptoms and cures in a few weeks. For others, it may not cause any symptoms. For some, the virus can cause more serious illnesses, including pneumonia and death.

According to health officials, most vaccinated people are asymptomatic or have very mild symptoms, and the virus rarely leads to hospitalization or death in these people.

Nevertheless, Omicron showed a change in symptoms common to many.

Dr. Catherine Pauling, an infectious disease specialist and a member of the Immunization Implementation Advisory Board, Told NBC News In January, cough, congestion, runny nose, and malaise appear to be prominent symptoms of the Omicron variant.

However, unlike the delta type, many patients did not lose their taste or smell. She said these symptoms may only reflect a particular population.

Will BA.2 cause a surge in the United States?

Experts have said they are watching carefully, especially as regulations continue to be lifted across the United States, but many, even if there is a surge, will not be at the level seen earlier this year. I’m saying that.

Dr. Ashish Ja, COVID-19 Response Coordinator at the White House, said last week, “We don’t expect a big surge here, but we need to be very careful and act on the same data as the whole pandemic. Must be done. ” ..

Fauci also anticipates a “increased number of cases” with BA.2, but said it is not necessarily the massive surge that other variants have caused.

“This is different from the switch from Delta to Omicron. This is a significant change in the virus, where we actually saw a significant increase in permeability beyond the Delta,” Huhn said. Says. “This is a subtle change, so the transfer rate does not actually accelerate as it does when switching from Delta to Omicron.”

Ghinai said he doesn’t think BA.2 will lead to the surge that was previously seen at the peak of Omicron, but changes are expected “at some point.”

“Here in Chicago, it’s almost at a historically low level in terms of COVID. It’s very likely that there’s some change in the infection,” he said. “I don’t think Delta will cause the surge as we’ve seen in the last few months because of Omicron.”

Experts are watching carefully as restrictions continue to be relaxed and booster immunity may begin to weaken, Huhn said.

“We’ve rolled back and we’ll see if there are more cases in the coming weeks,” he said.

Where was BA.2 detected?

Infections have increased recently as most COVID-19 restrictions have been relaxed throughout Europe, including Austria, the United Kingdom, Denmark, Germany and France. Over the past two weeks, both hospitalizations and deaths for COVID-19 have increased slightly in the United Kingdom.

This rise is partly driven by BA.2 and primarily those who have abandoned their masks and gathered in larger groups.

This variant was already detected in Illinois earlier this year, and the original Omicron strain continues to account for the majority of COVID cases in the region, but is expected to change soon.

Center for Pathogen Genomics and Microbial Evolution of Northwestern Medicine Said that a subvariant was found A Chicago resident who was tested for COVID-19 on January 18.

Dr. Allison Arwadi, director of public health at Chicago, said Tuesday that COVID risk remains low in the city. The data show that the number of cases in the BA.2 subvariant is doubling each week.

“Currently only Omicron is seen in Chicago and the Midwest. We see two major subvariants of Omicron. The surge of B1 is still about 69% and BA.2 is me. Some of the things we’re paying attention to, more contagious than B.1 and probably increasing around the world, are just over 30% at this point. In Chicago, we’ve seen BA.2. I think we’ll have the upper hand as it doubles about every 7 days, which means that most of our cases will be that BA.2 by the end of the month. ”

In the city, the number of new COVID cases is still small, but there is an increase in cases pointed out by health professionals. As of Thursday, the city had an average of 177 new cases of COVID per day, up 29% from a week ago when the city was 137.

“At this point, we don’t see the big signs we see in Europe, but we’ll be able to understand this honestly, perhaps by the end of the month when BA.2 is scheduled, while we continue to monitor. It’s dominant here. “

according to Estimate from Centers for Disease Control and PreventionThe BA.2 variant accounted for 30.6% of all COVID cases in several Midwestern states, including Illinois, Minnesota, Wisconsin, Michigan, Indiana, and Ohio.

Arwady emphasized that BA.2 represents even more cases in some states along the East Coast.

“New York, Connecticut, Pennsylvania, most of their cases are already BA.2,” she said.

According to the CDC, so-called “stealth” omicron variants are on the rise. For the New York areaThis strain currently accounts for at least 52% of new COVID cases in the region, and estimates suggest.

according to To the latest numbers from NYC HealthLast week, the city had an average of 892 new cases of COVID per day.

According to authorities, this is a 29% increase from a week ago when the city had an average of 689 cases per day.

Nationally, BA.2 variants are involved in 35% of new infections.

Why is the United States monitoring Europe?

In other countries, there are now signs that the number of cases is increasing due to the variant that infection leads to increased hospitalizations and even death.

“In Denmark, India, the Philippines, the United Kingdom, Switzerland, Sweden, Norway, Belgium, Hong Kong, South Africa and many other regions, it is still the predominant variant in many countries,” Huhn said. “We have found this to be the predominant strain, especially in the United Kingdom. The number of cases has increased and the number of cases has doubled in the last few weeks. The number of hospitalizations has increased and all these subspecies that have been prevalent in the last two years. Depending on the species, many of the trends that began in Europe, especially the United Kingdom, will eventually be seen here in the United States, so we are becoming more vigilant. With the increase in BA.2 cases, here in the United States. Hospitalization in the UK is on the rise as an early warning signal of what might happen. “

According to Angalone, Europe is usually up to a month ahead of the United States in the outbreak of COVID.

“We often consider Europe to be like a couple of weeks before us,” he said. “So are we going to see this kind of increase in a month or so? And we just don’t know.”

Arwady said she was “concerned” about the situation in Europe and her team was in contact with European officials.

Is vaccination effective against BA.2.

Preliminary data show that vaccination and boost immunization are equally effective in preventing symptomatic cases of BA.1, the original Omicron variant, and BA.2.

Already, two mRNA vaccine manufacturers currently approved for use in the United States are seeking approval for a second booster immunization against a particular population.

Drug maker modern Asked the Food and Drug Administration to approve the fourth shot on Thursday Of its COVID-19 vaccine as an additional immune dose for all adults.

This requirement is broader than rival pharmaceutical company Pfizer requiring regulators to approve booster shots for all seniors.

According to Ghinai, previous evidence also suggests that infection with one Omicron substrain is believed to provide protection from other Omicron substrains, but Huhn is rare, but re-infection. He said it was possible to get infected.

“I think it’s very likely that what we’ve seen here in Europe, where BA.2 is increasing relatively proportionally,” Ghinai said. “You will see BA.2 increase the proportion of cases. We have already seen it.”

Arwady emphasized that rising COVID in other countries may be a sign of the future, but it is not a guarantee.

“To be clear, we are not sure to follow. We may do, but there are some other countries that have experienced a surge in Omicron, and we are still resurrecting it. I haven’t seen it, “she said. “So we are still watching.”