The BA.2 subvariant of the Omicron coronavirus variant not only spreads faster, but can also cause more severe disease, according to a lab study.
The yet-to-be-peer-reviewed results, recently published on the BioRxiv preprint repository, show that the BA.2 subvariant may have characteristics that make it as capable of causing severe disease as the BA.2 variants. older coronaviruses.
On Thursday, the World Health Organization (WHO) said that while BA.2 is more transmissible than BA.1, the subvariant is not more severe.
“Among all the subvariants, BA.2 is more transmissible than BA.1. However, there is no difference in terms of severity,” said Maria Van Kerkhova, COVID-19 technical lead at WHO. in a video.
In the latest study, a Japanese team led by researchers from the University of Tokyo found that, like BA.1, Omicron’s BA.2 subvariant appears to largely evade immunity induced by COVID-19 vaccines. 19.
“Neutralization experiments show that vaccine-induced humoral immunity does not work against BA.2 like BA.1,” the study authors said.
Omicron was first reported in Botswana and South Africa in November 2021. Its BA.1 subvariant has since spread rapidly across the world and supplanted other variants such as Delta.
Since February this year, another sub-variant of Omicron, the BA.2 lineage, has been detected in several countries such as Denmark and the United Kingdom.
BA.2 began to outperform BA.1, suggesting it is more transmissible than the original Omicron, the researchers said.
“Although BA.2 is considered a variant of Omicron, its genomic sequence is significantly different from BA.1, suggesting that the virological characteristics of BA.2 are different from those of BA.1,” noted the authors.
When the researchers infected hamsters with BA.2 and BA.1, animals infected with BA.2 became sicker and had worse lung function.
In the tissue samples, the lungs of hamsters infected with BA.2 showed more damage than those infected with BA.1, they said.
“Our investigations using a hamster model showed that the pathogenicity of BA.2 is similar to that of an ancestral B.1.1 and superior to that of BA.1,” the authors noted.
Similar to the original Omicron, BA.2 was resistant to antibodies in the blood of people vaccinated against COVID-19.
It was also resistant to antibodies from people who had been infected with the earlier variants of SARS-CoV-2, the researchers said.
BA.2 was almost completely resistant to some monoclonal antibody treatments used to treat COVID-19 infection, they said.
“With a higher effective reproduction number and pronounced immune resistance of BA.2, it is evident that the spread of BA.2 may be a serious global health problem in the near future,” the authors added.
The reproduction number is a measure of transmission – the average number of people infected by an infected person.
(Only the title and image of this report may have been edited by Business Standard staff; the rest of the content is auto-generated from a syndicated feed.)