The BA.2 virus, a sub-variant of Omicron, can cause more serious diseases and appears to be able to thwart some of the key weapons we currently have against Covid-19.
There’s mixed evidence regarding research on Omicron’s distant cousin, but a Japanese study shows it could be as serious as Delta.
Omicron BA.2 variant
Resistant to treatments
According to an CNN reportNew lab experiments from Japan show that BA.2 can cause serious illness similar to older variants of Covid-19, including Delta.
Like Omicron, it also seems to largely escape the immunity created by vaccines. A booster injection restores protection, making disease after infection about 74% less likely.
BA.2 also appears to be resistant to some treatments, including sotrovimab, the monoclonal antibody currently used against Omicron.
BA.2 ‘stealth Omicron’
The findings were posted on Wednesday as a preprinted study on the bioRxiv server, before peer review.
“From a human perspective, it could be a worse virus than BA.1 and could be better able to transmit disease and cause worse,” said Dr. Daniel Rhoads, chief of microbiology at the Cleveland Clinic in Ohio.
A University of Tokyo researcher and the person who conducted the study, Kei Sato, argued that these findings prove that BA.2 should not be considered a type of Omicron and should be monitored more closely.
“As you may know, BA.2 is called ‘stealth Omicron,'” Sato told CNN† That’s because it doesn’t show up on PCR tests as an S gene target error like Omicron does.
“Labs therefore need to go the extra mile and sequence the virus to find this variant,” Sato says.
Mixed real world data
According to the World Health Organization (WHO), the BA.2 variant is estimated to be about 30% more contagious than Omicron.
So far, it has been detected in 74 countries and 47 states in the US.
The US Centers for Disease Control and Prevention estimate that about 4% of Americans with Covid-19 now have infections caused by BA.2, but many other parts of the world have more experience with this variant.
The WHO notes that the subvariant has become dominant in at least 10 other countries, including Bangladesh, Brunei, China, Denmark, Guam, India, Montenegro, Nepal, Pakistan and the Philippines, according to the World Health Organization’s weekly epidemiological report.
But there is mixed evidence on the severity of the BA.2 as hospital admissions in countries like South Africa and the UK continue to decline.
But in Denmark BA.2 is the leading cause of infections, hospitalizations and deaths are on the rise.
Resistant to monoclonal antibody treatments
The new study found that BA.2 can copy itself more quickly in cells than the original version of Omicron.
It is also more adept at sticking cells together. This allows the virus to make larger clumps of cells called syncytia.
This is worrying because these clumps then become factories for making more copies of the virus.
Delta was also good at creating syncytia, which is thought to be one of the reasons it was so destructive to the lungs.
Like the original Omicron, BA.2 was able to break down antibodies in the blood of people vaccinated against Covid-19.
It was also resistant to the antibodies of people infected with Covid-19 early in the pandemic, including Alpha and Delta.
And BA.2 was almost completely resistant to some monoclonal antibody treatments.
Experts have also warned countries against lifting mask mandates.
compiled by Narissa Subramoney