And like Omicron, it appears to largely escape the immunity created by the vaccine. Booster shots restore protection and reduce the chance of post-infection illness by about 74%.
BA.2 is also resistant to several treatments, including sotrovimab, the monoclonal antibody currently used against Omicron.
“From a human point of view, it’s a worse virus than BA.1, it’s more contagious, and it can exacerbate the disease,” said Dr. Daniel Rhodes, director of microbiology at the Cleveland Clinic, Ohio. .. Rhoads reviewed the study, but he was not involved in the study.
The Centers for Disease Control and Prevention is closely monitoring BA.2, said its director, Dr. Rochelle Walensky.
“There is no evidence that the BA.2 strain is more serious than the BA.1 strain. The CDC continues to monitor variants in domestic and international distribution,” she said Friday. “We will continue to monitor new data on the severity of human illness and findings from such papers made in the laboratory.”
BA.2 is highly mutated compared to the original Covid-causing virus that originated in Wuhan, China. It is also different from the latest pandemic virus, with dozens of genetic changes different from the original Omicron strain, just as the alpha, beta, gamma, and delta variants were different from each other.
Kei Sato, a researcher at the University of Tokyo who conducted the survey, proves that these findings should not be regarded as a kind of omicron, but should be monitored more closely. Insist.
“As you may know, BA.2 is called” stealth omicron, “” Sato told CNN. This is because it does not show up as a failure of the S gene target in PCR tests like Omicron. Therefore, the lab needs to take additional steps to sequence the virus to find this variant.
“The first thing to do is to establish a specific way to detect BA.2,” he says.
“It looks like you’re seeing a new Greek letter here,” agreed Deborah Fuller, a virologist at the University of Washington School of Medicine. He reviewed the study but was not part of his study.
Mixed real-world data on subvariant severity
According to the World Health Organization, BA.2 is estimated to be about 30% more contagious than Omicron. It has been detected in 74 countries and 47 US states.
The Centers for Disease Control and Prevention estimates that about 4% of Americans with Covid-19 have a BA.2 infection, but in many other parts of the world, this variant. Has a wealth of experience. According to the World Health Organization’s weekly epidemiological report, it is dominant in at least 10 countries: Bangladesh, Brunei, China, Denmark, Guam, India, Montenegro, Nepal, Pakistan and the Philippines.
However, in the real world, there is a lot of evidence about the severity of BA.2. Hospitalizations continue to decline in countries where BA.2 has built a foothold, such as South Africa and the United Kingdom. However, in Denmark, where BA.2 is the leading cause of infection, hospitalizations and deaths are increasing, according to WHO.
Resistant to monoclonal antibody therapy
A new study found that BA.2 was able to copy itself into cells faster than the original version of Omicron, BA.1. It is also good at sticking cells together. This allows the virus to form larger cell masses called syncytium than BA.1. This is a concern as these chunks will become factories for further mass production of virus copies. Delta was also good at producing syncytium. This is believed to be one of the reasons why it destroyed the lungs so much.
When researchers infected hamsters with BA.2 and BA.1, animals infected with BA.2 became ill and their lung function deteriorated. In tissue samples, the lungs of hamsters infected with BA.2 were more damaged than those of hamsters infected with BA.1.
Like the original Omicron, BA.2 was able to break through the antibodies in the blood of people vaccinated with Covid-19. They were also resistant to antibodies (such as alpha and delta) in people infected with Covid-19 early in the pandemic. BA.2 was also almost completely resistant to some monoclonal antibody therapies.
However, there was a bright point. Antibodies in the blood of people who recently took Omicron also appeared to have some protection against BA.2, especially if vaccinated.
And that raises an important point, says Fuller. BA.2 appears to be more contagious and pathogenic than Omicron, but may not eventually cause a more devastating wave of Covid-19 infection.
“One of the warnings we have to consider when getting a new variant that may seem more dangerous is the fact that the story has two sides,” says Fuller.
She says the virus is important, but as its host, we too.
“Our immune system is also evolving, and it’s driving things,” she said.
She says we are currently participating in the fight against the virus. The important question is who is in control.
“Our ultimate desire is to keep the host ahead of the virus. In other words, our immunity is one step ahead of the next variant. . “She said.
As such, Fuller says he feels it’s not time for the community to lift his mask obligations.
“Before this came out, I was about 10 feet away from the finish line,” she said. “It’s not a good idea to remove the mask now. It’s just going to extend it. Let’s get to the finish line.”