Here’s what we know about BA.2, the sister of Omicron

Agencies
February 3, 2022

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 Organization (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 per cent for households infected with BA.1 versus 39 per cent 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. 

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News Network
April 11,2024

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Bengaluru, Apr 11: Congress leader Rahul Gandhi and the party's unit in Karnataka have highlighted the statement of Class 12 Board exam topper from the state, Vedant Navi, and claimed that "it was a matter of pride as their schemes were bringing effective social and economic changes".

The Congress on Thursday launched a social media campaign by releasing posters and short videos.

Rahul Gandhi in his social media post said, “Such 'Success Stories' make me believe and ensure that our 'Mahalakshmi' guarantee of putting Rs 1 lac every year in women's accounts will prove to be a revolutionary step to shaping the country's fate.”

“Congress's Gruha Lakshmi scheme going on in Karnataka under which more than 1 crore women get Rs 2,000 every month, using the same money a mother taught her son Vedant and he got second rank in the whole state in PUC exam,” Rahul Gandhi stated.

“Vedant's story is a living example of Indian women's penance and willpower to strengthen the house with pai-pai. Imagine, when women of poor families across the country will get Rs 1 lakh every year through the 'Mahalakshmi Yojana', how many Vedantas will change the future of the family with their talent? This historic plan of Congress will give the dreams of poor families a flight into reality,” Rahul Gandhi said.

The Congress in Karnataka said the schemes of the government were giving succour to the people. “It is a matter of pride that in a span of 10 months, our government’s schemes are bringing effective social and economic changes,” the party claimed.

“It is a testimony to the success of the Gruha Lakshmi scheme that the family of Vedant, who secured first rank in the Arts stream, was supported by the money provided by the Gruha Lakshmi scheme. Our schemes have brought changes in many people’s lives. The Congress party has built the lives of the people and thereby built the nation,” the Congress stated.

Vedant Navi had secured first rank in Arts Stream in Karnataka. He is the overall second-topper.

“My father is no more. My mother faced difficulties as the family was debt-ridden. In this crunch time, the money received through the Gruha Lakshmi scheme (Rs 2,000 every month given for women heads of family) helped my studies and hostel stay and other expenditures,” Vedant had stated.

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News Network
April 13,2024

Mangaluru, Apr 13: Prime Minister Narendra Modi is all set to campaign for the upcoming and much awaited Lok Sabha election in coastal Karnataka by holding a mega roadshow in Mangaluru. 

Meanwhile, the organisers have announced a slight delay in the commencement of Modi's scheduled roadshow on April 14 in Mangaluru.

Addressing the media BJP principal secretary and Karnataka MLA V Sunil Kumar said: Originally the roadshow was scheduled to begin at 5 pm., but it will start at 7:30 pm."

As planned, the Roadshow will kick off from Narayan Guru Circle, where Prime Minister Modi will pay floral tribute to Sri Narayan Guru idol. From there, the Roadshow will proceed and conclude at Navabharat Circle. 

Mr Kumar urged people traveling to Mangaluru to see Mr Modi's visit by 7 p.m. and stand behind the barricades. The roadshow is estimated to conclude at 8:30 pm.

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News Network
April 15,2024

New Delhi: India is likely to experience above-normal cumulative rainfall in the 2024 monsoon season with La Nina conditions likely to set in by August-September, the IMD has said on Monday.

However, normal cumulative rainfall does not guarantee uniform temporal and spatial distribution of rain across the country, with climate change further increasing the variability of the rain-bearing system.

Climate scientists say the number of rainy days is declining while heavy rain events (more rain over a short period) are increasing, leading to frequent droughts and floods.

Based on data between 1951-2023, India experienced above-normal rainfall in the monsoon season on nine occasions when La Nina followed an El Nino event, India Meteorological Department chief Mrutyunjay Mohapatra told a press conference here.

Positive Indian Ocean Dipole conditions are predicted during the monsoon season. Also, the snow cover in the Northern Hemisphere is low. These conditions are favourable for the Indian southwest monsoon, he said.

Moderate El Nino conditions are prevailing at present. It is predicted to turn neutral by the time monsoon season commences. Thereafter, models suggest, La Lina conditions may set in by August-September, Mohapatra said.

India received "below-average" cumulative rainfall -- 820 mm compared to the long-period average of 868.6 mm -- in 2023, an El Nino year. Before 2023, India recorded "normal" and "above-normal" rainfall in the monsoon season for four years in a row.

El Nino conditions -- periodic warming of surface waters in the central Pacific Ocean -- are associated with weaker monsoon winds and drier conditions in India.

Three large-scale climatic phenomena are considered for forecasting monsoon season rainfall.

The first is El Nino, the second is the Indian Ocean Dipole (IOD), which occurs due to differential warming of the western and eastern sides of the equatorial Indian Ocean, and the third is the snow cover over the northern Himalayas and the Eurasian landmass, which also has an impact on the Indian monsoon through the differential heating of the landmass.

The southwest monsoon delivers about 70 percent of India's annual rainfall, which is critical for the agriculture sector. Agriculture accounts for about 14 percent of the country's GDP.

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