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COVID-19 Explained: 10 Things We Know About BA.2 Sub-Variant Of Omicron

Several countries including Denmark, India, Sweden and Singapore have reported cases of BA.2 lineage, a sub-variant of the Omicron variant of COVID-19

COVID-19 Explained: 10 Things We Know About BA.2 Sub-Variant Of Omicron
Amid a spike in the cases of Omicron variant, there are reports of an infectious sub-variant of Omicron - BA.2 lineage
  • The Omicron variant has three lineages - BA.1, BA.2 and BA.3
  • BA.2 could be 1.5 times more infectious than BA.1: Statens Serum Institut
  • BA.2 is unlikely to cause another COVID wave in India: Dr Sandeep Budhiraja

New Delhi: Ever since the SARS-CoV-2 was first reported in December 2019 in China, the virus has undergone multiple mutations and new variants have emerged. Currently, the Omicron variant (B.1.1.529) of COVID-19 is circulating across the world and is dominant in India. As per the Indian SARS-CoV-2 Genomics Consortium (INSACOG), Omicron is now in the community transmission phase in the country and has become the dominant variant in multiple metros, where new cases have been rising exponentially. Amid a spike in the cases of Omicron variant, there are reports of an infectious sub-variant of Omicron – BA.2 lineage.

Also Read: India’s Omicron Wave May Intensify In Coming Weeks, Say Experts

Several countries including Denmark, India, Sweden and Singapore have reported cases of BA.2 lineage. On January 21, in its weekly bulletin, the UK Health Security Agency (UKHSA) designated BA.2 as a variant under investigation.

The outer layer of the virus; the spikes on the virus are called spike protein. The spikes have various genes. Several labs have indicated that for one widely used PCR test, one of the three target genes is not detected (called S gene dropout or S gene target failure) in the Omicron variant. However, not all RT-PCR test kits can identify the Omicron variant, especially the BA.2 lineage. Hence, it is recommended to rely on genomic sequencing for the identification of the variant. In fact, INSACOG in its latest bulletin of January 10 which was released on Sunday (January 23) said,

BA.2 lineage is in a substantial fraction in India and S gene dropout based screening is thus likely to give high false negatives.

Banega Swasth India team spoke to experts and here’s what we know about BA.2 lineage so far:

1. As per the World Health Organisation (WHO), Omicron is a highly divergent variant with a high number of mutations, including 26-32 mutations in the spike protein, some of which are associated with humoral immune escape potential and higher transmissibility. The Omicron variant has three lineages – BA.1, BA.2 and BA.3. Explaining the term lineage, Dr Chandrakant Lahariya, a consultant physician and Epidemiologist based in New Delhi said,

Sub-lineage is more like a sibling; they are from the same family. All three lineages share most of the key characteristics with minor variations.

Also Read: COVID-19 And Omicron: About Time You Break Up With A Cloth Mask? Here’s What Experts Have To Say

2. “In total, 40 countries have uploaded 8,040 BA.2 sequences to Global Initiative on Sharing All Influenza Data (GISAID) since November 17, 2021. At this point, it is not possible to determine where the sub-lineage may have originated. The first sequences were submitted from the Philippines, and most samples have been uploaded from Denmark (6,411)”, said UKHSA in its weekly update dating January 21.

3. Preliminary calculations suggest BA.2 could be 1.5 times more infectious than BA.1, Denmark’s top infectious disease authority, Statens Serum Institut (SSI), said in a note on Wednesday (January 26), as reported by a news agency Reuters. However, an initial analysis by the institute showed no difference in the risk of hospitalisation for BA.2 compared to BA.1.

There is some indication that it is more contagious, especially for the unvaccinated, but that it can also infect people who have been vaccinated to a greater extent, SSI’s technical director Tyra Grove Krause said at the briefing, reported Reuters.

4. In a press note, SSI said that BA.1 and BA.2 have many differences in their mutations in the most important areas. In fact, the difference between BA.1 and BA.2 is greater than the difference between the original variant and the Alpha variant, it said.

Such differences can lead to different properties for instance concerning infectiousness, vaccine efficiency or severity, reported SSI.

Also Read: Dangerous To Assume Omicron Will Be The Last Variant; We Can End The Acute Phase Of COVID-19 This Year: WHO Chief

5. “The clinical features of BA.2 are similar to that of Omicron and causes mild disease. In terms of immune escape – reinfection or a breakthrough infection – BA.2 lineage seems to exhibit matching traits to that of Omicron. However, some reports are claiming that it may be more transmissible and infectious than other sub-variants. But it’s too early to say that”, said Dr Sandeep Budhiraja, Group Medical Director, Max Healthcare.

6. Dr Budhiraja also said that it is unlikely for people who have been exposed to the Omicron variant to get reinfection with the BA.2 lineage in a short span of time. He added,

What we know so far is that if you have been infected with the Omicron variant of COVID-19, you generally develop neutralising antibodies to most of the other strains including Delta, Alpha and Gama.

7. Dr Lahariya said that all three lineages are highly transmissible; hence, saying one is more transmissible than the other is misleading. He said,

In different settings, different variants emerge. In the beginning, the majority of the circulation was due to BA.1 lineage but now cases of BA.2 are being reported therefore, all the discussion around it. However, there is nothing to be worried about it.

Also Read: Here’s Why WHO Experts Are Worried About Omicron Variant of COVID-19

8. When asked if BA.2 lineage can bring another wave of COVID-19, Dr Budhiraja said, “very unlikely”. Since the Omicron variant has spread extensively in the community, the variant is expected to give immunity against its lineage as well.

For a variant to cause a new wave, it has to be significantly different from the previous strains. So far, it is not emerging like that in case of BA.2 lineage but, it is too early to say anything, said Dr Budhiraja.

9. Will Omicron be the last variant of COVID-19? Experts say no. Dr Meera Chand, COVID-19 Incident Director at UKHSA, said,

It is the nature of viruses to evolve and mutate, so it’s to be expected that we will continue to see new variants emerge as the pandemic goes on.

Agreeing with Dr Chand, Dr Budhiraja told the Banega Swasth India team that because of multiple infections, vaccinations and precautionary doses, more people will be immune to developing serious disease and a majority will develop a mild disease similar to what we saw in the Omicron wave in India. He said,

With Omicron, we saw a short-lasting wave and most people were managed at home. We are hoping that future mutations will probably behave more like this but, of course, one needs to keep healthcare services at alert mode now.

10. Dr Budhiraja also said that we will learn to live with COVID-19 like flu viruses. For example, Swine Flu hasn’t become less dangerous over the years but the number of cases being reported is manageable. He said,

The problem occurs when a virus leads to the clustering of cases in a short span of time. That’s when healthcare infrastructure gets overburdened.

Also Read: Omicron Should Not Be Categorised As ‘Mild’, It Is Hospitalizing And Killing People: WHO Chief

NDTV – Dettol have been working towards a clean and healthy India since 2014 via the Banega Swachh India initiative, which is helmed by Campaign Ambassador Amitabh Bachchan. The campaign aims to highlight the inter-dependency of humans and the environment, and of humans on one another with the focus on One Health, One Planet, One Future – Leaving No One Behind. It stresses on the need to take care of, and consider, everyone’s health in India – especially vulnerable communities – the LGBTQ populationindigenous people, India’s different tribes, ethnic and linguistic minorities, people with disabilities, migrants, geographically remote populations, gender and sexual minorities. In wake of the current COVID-19 pandemic, the need for WASH (WaterSanitation and Hygiene) is reaffirmed as handwashing is one of the ways to prevent Coronavirus infection and other diseases. The campaign will continue to raise awareness on the same along with focussing on the importance of nutrition and healthcare for women and children, fight malnutrition, mental wellbeing, self care, science and health, adolescent health & gender awareness. Along with the health of people, the campaign has realised the need to also take care of the health of the eco-system. Our environment is fragile due to human activity, which is not only over-exploiting available resources, but also generating immense pollution as a result of using and extracting those resources. The imbalance has also led to immense biodiversity loss that has caused one of the biggest threats to human survival – climate change. It has now been described as a “code red for humanity.” The campaign will continue to cover issues like air pollutionwaste managementplastic banmanual scavenging and sanitation workers and menstrual hygiene. Banega Swasth India will also be taking forward the dream of Swasth Bharat, the campaign feels that only a Swachh or clean India where toilets are used and open defecation free (ODF) status achieved as part of the Swachh Bharat Abhiyan launched by Prime Minister Narendra Modi in 2014, can eradicate diseases like diahorrea and the country can become a Swasth or healthy India.


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