As BA.2 variant spreads to US, WHO warns of future virus mutations

]

New COVID variant, BA.2, reported in US

]

A new COVID variant – labeled as a “variant under investigation” by authorities in the U.K. - has been reported.

The variant, BA.2 has been found in 40 countries, including the U.S., U.K. India, Germany and Australia, is linked to more than 8,000 cases worldwide. According to The Hill, not much is known about the variant, including its transmissibility and severity. It is unclear how current vaccines are responding to the variant.

BA.2 is believed to be a subvariant of the omicron variant, known as BA.1. It has been increasing in countries such as Denmark, Norway and Sweden, where it’s believed to have overtaken the original omicron variant.

Officials in Washington State confirmed two cases of the variant were found earlier this month. It’s believed there are about 100 cases in the U.S.

COVID-19 update: Why did UK call BA.2 a ‘variant under investigation’?

]

At least 40 countries have detected this omicron sub-lineage since November 17, 2021

The United Kingdom declared BA.2 a variant under investigation amid an increase in the number of patients infected by the that sub-lineage of the omicron variant of the novel coronavirus. The prevalence of the variant has increased to 426 since it was first isolated in the country December 6. 2021.

At least 40 countries have detected this variant since November 17, 2021. India has reported 530 samples to the Global Initiative on Sharing Avian Influenza Data (GISAID) — the world’s largest database of novel coronavirus genome sequences. The variant has also been found in Denmark, Sweden, Philippines, France, Norway and Singapore.

The designation was based on rising numbers domestically and globally, the United Kingdom Health Security Agency (UKHSA) noted in its latest update from January 21, 2021. “There is still uncertainty around the significance of the changes to the viral genome, and further analyses will now be undertaken.”

So far, there is insufficient evidence to determine whether BA.2 causes more severe illness than Omicron BA.1, said Dr Meera Chand, COVID-19 Incident Director at UKHSA. She added:

We do know that the BA.2 variant does not have the mutation which results in an S-gene target failure (SGTF) during some polymerase chain reaction (PCR) tests — a quick method used widely to detect which variant of the SARS-CoV-2 variant it is since genome sequencing is a time consuming process. This is why it was popularly dubbed as the ‘stealth variant’ in December when it was first discovered.

The ‘stealth’ variant has 32 mutations in common with BA.1 but also has 28 other mutations, she noted. “It remains to be seen what this means for the virus’ virulence and infectivity.”

BA.2 is unlikely to have any severe impact on the ongoing omicron wave, argued Tom Peacock, a virologist at the Imperial College London, in a series of tweets. “Several countries are near, or even past the peak of BA.1 waves. I would be very surprised if BA.2 caused a second wave at this point.”

Even with slightly higher transmissibility, this absolutely is not a delta to omicron change and instead is likely to be slower and more subtle, he said. While BA.1 is now the dominant strain in UK, BA.2 is likely to replace it soon.

The ‘stealth’ version is less likely to evade immunity than omicron to evade immunity, according to predictions by Bloom Lab, a Seattle-based lab studying molecular evolution of proteins and viruses, made in December last year.

Read our coverage of the COVID-19 pandemic here.

Omicron BA.2 ‘sub-variant’ found in substantial fraction in India: What we know so far

]

BA.2 lineage, an infectious sub-variant of Omicron, has been found in a substantial fraction in India as the Covid-19 peak is likely to come in the next fortnight.

The earlier prediction was that the peak of the third wave of the infection is likely between 1 and 15 February.

The INSACOG, in its latest bulletin, said while most Omicron cases in the country so far have been asymptomatic or mild, hospitalisations and ICU cases have increased in the current wave and the threat level remains unchanged.

“Omicron is now in community transmission in India and has become dominant in multiple metros, where new cases have been rising exponentially. BA.2 lineage is in a substantial fraction in India and S gene dropout based screening is thus likely to give high false negatives,” the INSACOG said.

S-gene drop-out is a genetic variation like that of the Omicron variant.

“The recently reported B.1.640.2 lineage is being monitored. There is no evidence of rapid spread and while it has features of immune escape, it is currently not a variant of concern. So far, no case has been detected in India,” the INSACOG said.

It also said that Omicron is now in community transmission in India and has become dominant in Delhi and Mumbai where new cases have been rising exponentially.

Omicron wave continues to expand globally, but the rate of hospitalisation during this wave is less, the bulletin added.

Omicron sub-lineage BA.2 variant throws up new virus questions

Scientists are keeping a close watch on a recently-discovered sub-variant of the Omicron version of the Covid-19 virus to determine how its emergence could effect future pandemic spread.

The initial Omicron variant has become the dominant virus strain in recent months but British health authorities have notably identified hundreds of cases of the latest version, dubbed BA.2, while international data suggest it could spread relatively quickly.

The UK Health Security Agency (UKHSA) identified over 400 cases in Britain in the first ten days of this month and has indicated the latest variant has been detected in some 40 other countries, accounting for a majority of most recent cases in some nations including India, Denmark and Sweden.

The UKHSA indicated it had designated the BA.2 sub-lineage as a variant under investigation (VUI) as cases of it were on the increase even if, in Britain, the BA.1 lineage currently remains dominant.

BA.2 has yet to be designated a variant of concern – but French epidemiologist Antoine Flahault says countries have to be alert to the latest development as scientists ramp up surveillance.

Subscribe to Mint Newsletters * Enter a valid email * Thank you for subscribing to our newsletter.

New COVID-19 subvariant ‘BA.2’ detected in the state of Washington

]