Coronavirus: Omicron is the dominant strain currently; what about its ancestors?

Omicron is the dominant strain of the coronavirus right now accounting for more than 98% of the cases worldwide. It's been almost a year no new variant of the virus has been detected.

Until now, Omicron has mutated to several sub variants. It has been found that the sub variants of Omicron are smarter in evading immunity than the parent variant.

Read: Those who had COVID must watch out for stroke signs

However, despite the fact that only the virus is in circulation for over a year in sharp contrast to 2-3 deadly forms of the same virus in the beginning of the pandemic does not mean that we should drop the guards.

Omicron is currently the dominant variant circulating globally, accounting for >98% of viral sequences shared on GISAID after February 2022, the World Health Organisation (WHO) says.

As on October 12, the following sub variants of Omicron are under strict monitoring:

BA.5

BA.2.75

BJ.1

BA.4.6

XBB

BA.2.3.20

"There is a lot of diversity in #Omicron right now, with >300 sub lineages circulating. ~95% of those are BA.5 sublineages, ~20% of which are BQ.1 sublineages. We need better surveillance, sequencing & sharing of data so that rapid & robust analyses can be conducted regularly," WHO Chief Epidemiologist, Maria Van Kerkhove had tweeted recently.

Last year in September, the delta variant of the coronavirus was the dominant strain. It is considered to be one of the fittest strains of COVID till date. First detected in India, delta led the disastrous wave of COVID.

Also known as B.1.617.2 the delta variant was tagged as a variant of interest on April 4, 2021 and after a month it was tagged as variant of concern.

Before the disastrous delta, there were gamma, beta and alpha variants of the COVID which were first detected in Brazil, South Africa and the United Kingdom, respectively.

With Omicron accountable for a large number of COVID cases, it can be believed that the ancestor strains of the virus may have died out. However, the science behind this can be different and difficult for normal people to understand.

But with the current trend of the infection it can be said that other variants are not prevalent right now.

The US CDC had designated Alpha, Beta and Gamma variants as Variants Being Monitored (VBM) in September 2021.

In India, BA.2.7.5 was the dominant variant for some time and right now cases of XBB, a recombinant strain of the Omicron, is being seen.

We have seen a change in the pattern of COVID symptoms in each variant-led infection wave. While loss of taste and smell was a telltale sign of COVID during the beginning of the pandemic, shortness of breath was a major concern during the delta wave.

In the Omicron wave, sore throat and congested nose have been found as the top symptoms of the infection.

Few symptoms like fever, headache, fatigue, were seen in all the waves.

When the COVID causing coronavirus was first detected it was said to be a novel virus. Nations geared up to tackle the spread of this novel virus by lockdowns and engaging in developing vaccines.

However, as per a recent report published in Nature, "Genome analysis finds SARS-CoV-2 and bat coronaviruses shared an ancestor just a few years ago, but extensive recombination has muddied the picture.”

The virus that causes COVID-19 probably shared an ancestor with bat coronaviruses more recently than scientists had thought. But finding the direct ancestor of SARS-CoV-2 is very unlikely, the report adds.

"In the latest analysis, presented at the 7th World One Health Congress in Singapore on 8 November, scientists compared fragments of coronavirus genomes. The analysis suggests that some sections of bat coronaviruses and SARS-CoV-2 shared a common ancestor as recently as 2016 — just three years before the virus emerged in people in late 2019. The work has not been peer reviewed," the report sheds light on the COVID ancestors.