Subvariant BA.2: What we know about the globally dominant 'Stealth Omicron' COVID strain

Just as governments across the world have eased COVID-19-related restrictions, the spectre of another wave of the virus is sparking concern among the scientific community.

Omicron subvariant BA.2, which is being dubbed with the moniker "Stealth Omicron," is now believed to be the dominant strain of COVID-19 in the world.

In the US, it is causing more than half of the country's weekly infections.

According to the data from the Centers for Disease Control and Prevention (CDC), infections from BA.2 have jumped 39 per cent in a week, pushing infection rates to between 51-59 per cent.

In China, too, a new wave of coronavirus has been linked to the spread of subvariant BA.2, with the country's largest city Shanghai - a city home to 26 million people - beginning a phased lockdown this week to contain it.

In January, the subvariant - which is believed to be more contagious than the original Omircon variant whose spread has begun to slow - was initially noted in over 40 countries, including the UK, Sweden and India.

It is worth noting that while BA.1 has dominated case numbers around the world, it causes less severe disease compared to the delta variant.

Recent studies from the U.K. and Denmark suggest that BA.2 may pose a similar risk of hospitalization as BA.1.

Given the speed at which it has outpaced other Omicron subvariants, BA.2 is sparking fears that a more transmissible strain of coronavirus is actively spreading through the community.

Omicron, which is also referred to as B.1.1.529, has three main substrains, BA.1, BA.2, and BA.3, according to the World Health Organisation (WHO).

Up until now, it has been BA.1 that has been dominating with the WHO estimating it makes up a large majority of all Omicron cases.

However, the BA.2 has