Coronavirus: Know why Omicron subvariant BA.2 spreads faster

Just when we were about to heave a sigh of relief due to the falling number of COVID cases, another subvariant of the coronavirus variant Omicron emerged. While experts at the World Health Organisation (WHO) have said that it is on the rise, new lab experiments from Japan show that BA.2 Omicron sub variant may have features that make it as capable of causing serious illness as older variants of COVID-19, including Delta, reported CNN.

The Omicron sub variant, BA.2, first originated in the Philippines in November 2021.

We all know about the mutating nature of the virus and know that mutation is the reason why new variants of a virus are formed. Sometimes as virus mutates into variants it branches off or splits into sub variants or sub lineages. As per reports, the Delta variant of coronavirus has more than 200 different sub variants. Currently, the Omicron variant has BA.1, BA.2, BA.3 and B.1.1.529 sub variants of which the BA.1 was dominant a few months before and scientists have recently warned about the BA.2 sub variant.

On the viral properties of the Omicron sub variant, a Nature report says, "researchers think that a large part of the reason Omicron quickly replaced the Delta variant is its ability to infect and spread among people who had been immune to Delta. So one possibility for BA.2’s rise is that it’s even better than BA.1 at overcoming immunity — potentially including the protection gained from a BA.1 infection."

Experts have found many distinguishable mutations in BA.2 from BA.1 mostly in the spike protein region which confirms the speculation around the immunity evasive property of the virus.

The Omicron BA.2 is spreading faster in countries like Denmark, the Philippines and South Africa. Preliminary research studies have shown that the BA.2 sub variant can overcome immunity from vaccination and can also dodge the immunity of the body developed through previous infection with earlier variants.

Many researchers have said that even double-vaccinated and boosted individuals are more susceptible to BA.2 Omicron infection than to BA.1 Omicron and have said that the unvaccinated ones are at a heightened risk of contracting the infection.

A research study conducted by Denmark's SSI has found that BA.2 is substantially more transmissible than the BA.1 sub variant. This study included 8,500 households and 18,000 individuals.

A similarity in both the sub variants was detected by David Ho. Columbia University virologist David Ho's study says that both these sub variants are similarly efficient in resisting neutralizing antibodies in people who had been vaccinated or previously infected.

A similar opinion on the sub variant has been given by Francois Balloux, Professor of Computational Systems Biology and director of the UCL Genetics Institute. As per the BBC, h e said that BA.1 and BA.2 "can be considered as two epidemiologically largely equivalent sub-lineages of Omicron.”

Omicron sub variant BA.1 was notorious for being the super spreader and had the highest transmission rate than all its ancestors.

Omicron BA.1 sub variant's contagious trait was attributed to its ability of escaping the immunity and this is why this super spreader variant replaced the Delta variant within no time.

The other sub variant, BA.2, is also said to have the same property and is expected to be excellent in overcoming immunity and hence researchers expect it to be a super spreader very soon. On February 17, experts at the WHO had said BA.2 to be more transmissible than others. The experts had said that while they are monitoring the situation there is no evidence that the BA.2 sub variant is more lethal than BA.1.