The emerging BA.2 Omicron sub-variant does not appear to be more severe than the original BA.1 – but is more transmissible and more able to infect vaccinated people, according to reports.
The subvariant, one of at least four descendants of Omicron, has been detected in 57 countries since emerging in southern Africa 10 weeks ago, the World Health Organization said.
It is widely being dubbed “stealth Omicron” because of a genetic trait that makes it harder to detect.
BA.2 is more transmissible than BA.1 and is more able to infect the vaccinated, according to a Danish study that analyzed COVID-19 infections in more than 8,500 households in the country between December and January, Reuters reported.
The study found that people infected with the BA.2 sub-variant were roughly 33 percent more likely to infect others, compared to those infected with BA.1.
The BA.1 sub-variant accounts for more than 98 percent of global Omicron cases, but BA.2 has quickly become the dominant strain in Denmark, replacing BA.1 in the second week of January, according to Reuters.
“We conclude that Omicron BA.2 is inherently substantially more transmissible than BA.1, and that it also possesses immune-evasive properties that further reduce the protective effect of vaccination against infection,” the researchers said
The study, which has not yet been peer-reviewed, was conducted by researchers at Statens Serum Institut, Copenhagen University, Statistics Denmark and Technical University of Denmark.
“If you have been exposed to Omicron BA.2 in your household, you have 39 percent probability of being infected within seven days. If you instead had been exposed to BA.1, the probability is 29 percent,” lead study author Frederik Plesner told the news outlet.
BA.2 cases also have been confirmed in the US, Britain, Sweden and Norway, but to a much lesser extent than in Denmark, where it accounts for about 82 percent of cases.
Meanwhile, vaccines continue to provide similar protection against the different forms of Omicron, according to Dr. Boris Pavlin of the WHO’s COVID-19 Response Team.
Based on data from Denmark, there appears to be no difference in disease severity, Pavlin said.
“Looking at other countries where BA.2 is now overtaking, we’re not seeing any higher bumps in hospitalization than expected,” he added.
Many insist that BA.2 has shown no reason not to carry on learning to live with COVID-19 as a new reality.
“Variants have come, variants have gone,” Robert Garry, a virologist at Tulane University School of Medicine, told the Washington Post.
“I don’t think there’s any reason to think this one is a whole lot worse than the current version of Omicron.”
With Post wires