BA.2 is like Omicron's sister; Here's what we know about it so far
Queensland, Feb 3 (The Conversation): Cases of the SARS-CoV-2 variant Omicron have escalated globally over the past two months, with many countries experiencing peaks higher than previous variants.
Now we're seeing cases of a sub-variant of Omicron, known as BA.2, emerge in Australia and more than 50 countries.
Rather than a daughter of the Omicron variant BA.1 (or B.1.1.529), it's more helpful to think of BA.2 as Omicron's sister.
Remind me, what is a variant?
Viruses, and particularly RNA viruses such as SARS-CoV-2, make lots of mistakes when they reproduce. They can't correct these mistakes, so they have a relatively high rate of errors, or mutations, and are constantly evolving.
When the genetic code of a virus changes as a result of these mutations, it's referred to as a variant.
Omicron is a highly divergent variant, having accumulated more than 30 mutations in the spike protein. This has reduced the protection of antibodies from both prior infection and vaccination, and increased transmissibility.
When do health authorities worry about a new variant?
If changes in the genetic code are thought to have the potential to impact properties of the virus that make it more harmful, and there's significant transmission in multiple countries, it will be deemed a variant of interest .
If a variant of interest is then shown to be more infectious, evade protection from vaccination or previous infection, and/or impact the performance of tests or treatments, it is labelled a variant of concern .
The World Health Organisation (WHO) classified Omicron a variant of concern on November 26 because of its potential to cause higher reinfection rates, increased transmissibility and reduced vaccine protection.
What is the Omicron lineage?
A lineage, or sub-variant, is a genetically closely related group of virus variants derived from a common ancestor.
The Omicron variant comprises three sub-lineages: B.1.1.529 or BA.1, BA.2 and BA.3.
While the WHO has not given BA.2 a separate classification, the United Kingdom has labelled BA.2 a variant under investigation . So not yet a variant of interest or concern, based on WHO definitions, but one that is being watched closely.
This is not the first variant to have sub-lineages. Late last year, Delta plus or AY.4.2 was reported widely, then Omicron came along.
What's different about BA.2?
While the first sequences of BA.2 were submitted from the Philippines and we have now seen thousands of cases, including in the United States, the UK and some in Australia its origin is still unknown.
The exact properties of BA.2 are also still being investigated. While there is no evidence so far that it causes more severe disease, scientists do have some specific concerns.
1. It's harder to differentiate
A marker that helped differentiate Omicron (BA.1) from other SARS-CoV-2 variants on PCR tests is the absence of the the S gene, known as S gene target failure . But this is not the case for BA.2.
The inability to detect this lineage in this way has led some to label it the stealth sub-variant .
But it doesn't mean we can't diagnose BA.2 with PCR tests. It just means when someone tests positive for SARS-CoV-2, it will take us a little longer to know which variant is responsible, through genome sequencing. This was the case with previous variants.
2. It may be more infectious
Perhaps most concerning is emerging evidence BA.2 may be more infectious than the original Omicron, BA.1.
A preliminary study from Denmark, where BA.2 has largely replaced BA.1, suggests BA.2 increases unvaccinated people's susceptibility of infection by just over two times when compared to BA.1.
The researchers suggest fully vaccinated people are 2.5 times more susceptible to BA.2 than BA.1, and those who were booster vaccinated are nearly three times more susceptible.
The study examined more than 2,000 primary household cases of BA.2 to determine the number of cases that arose during a seven-day follow up period.
The researchers also estimated the secondary attack rate (basically, the probability infection occurs) to be 29% for households infected with BA.1 versus 39% for those infected with BA.2.
This Danish study is still a preprint, meaning it's yet to be checked by independent scientists, so more research is needed to confirm if BA.2 is truly more infectious than BA.1.
We're likely to see new variants We should expect new variants, sub-variants and lineages to continue to emerge. With such high levels of transmission, the virus has abundant opportunity to reproduce and for errors or mutations to continue to arise.
The way to address this, of course, is to try to slow transmission and reduce the susceptible pool of hosts in which the virus can freely replicate.
Strategies such as social distancing and mask-wearing, as well as increasing vaccination rates globally, will slow the emergence of new variants and lineages. (The Conversation)
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BCB official calling Tamim 'an Indian agent' invites wrath of Bangladesh players
Dhaka (PTI): A senior Bangladesh Cricket Board (BCB) official calling former captain Tamim Iqbal "an Indian agent" has not gone down well with the players in the country.
Tamim, one of the finest openers to have come out of Bangladesh, had advised the BCB to not be driven by emotion while deciding the way forward on the national team's participation in the T20 World Cup in India.
Nazmul, chairman of BCB finance committee, called the left-hander opener "an Indian agent" in a Facebook post.
"This time, the people of Bangladesh witnessed, with their own eyes, the emergence of yet another proven Indian agent," he wrote.
The post received immediate backlash from former and current cricketers, including Taskin Ahmed, Momimul Haque and Taijul Islam.
Even the Cricketers' Welfare Association of Bangladesh (CWAB) expressed shock at Nazmul's comments.
"A comment made by BCB director M Nazmul Islam regarding former national captain Tamim Iqbal has come to the attention of the Cricketers' Welfare Association of Bangladesh. We are stunned, shocked, and outraged by it.
"Such a remark by a board official about the most successful opener in Bangladesh's history, who represented the country for 16 years, is utterly condemnable.
"Not only because it concerns a player like Tamim, but such comments about any cricketer of the country are unacceptable and insulting to the entire cricketing community," the players' body said in a statement.
The 36-year-old Tamim played 70 Tests, 243 ODIs and 78 T20 Internationals for his country in a fairly accomplished career.
"We strongly protest against this comment. When a responsible board director makes such remarks on a public platform, it also raises serious questions about the code of conduct of board officials," it said.
"We have already submitted a protest letter to the BCB president, demanding a public apology from the concerned board director and that he be brought under accountability. We hope the BCB president will take appropriate action as soon as possible," CWAB added.
Bangladesh wrote to the International Cricket Council to move their T20 World Cup games out of India after the BCCI instructed IPL franchise KKR to release Mustafizur Rahman ahead of the 2026 edition without giving a specific reason.
"Cricket is the life of Bangladesh. A recent comment surrounding a former national captain who has made a major contribution to the game has caused many to reflect," said pacer Taskin.
"I believe that such remarks directed at a former cricketer of the country are not helpful in the interest of Bangladesh cricket. I hope the concerned authorities will consider the matter seriously and adopt a more responsible stance in the future," he said.
Mominul added: "The comment made by BCB director M Nazmul Islam regarding former national captain Tamim Iqbal is completely unacceptable and insulting to the country's cricketing community. Such behaviour towards a cricketer is in direct conflict with the board's responsibility and ethics," said Mominul.
"A senior cricketer was not given even the minimum respect; instead, he was deliberately humiliated in public. Such remarks show a lack of even basic decorum regarding where and how to speak while holding such a high responsibility.
"I strongly condemn this comment and firmly demand a public apology from the concerned director and that he be brought under accountability. I call upon the BCB to take swift and strict action," said Mominul.
