'Stealth Omicron': Is subvariant BA.2 a more transmissible strain of COVID and should we be worried?

Just as governments across the world have voiced their intentions to ease 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 causing concern in the US as fears of yet another wave of COVID-19 gains pace.

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

In Denmark, it became the dominant subvariant, and now researchers in the US are bracing for a similar trend.

"A lot of us were assuming that it was going to quickly take off in the United States just like it was doing in Europe and become the new dominant variant," Nathan Grubaugh, an associate professor of epidemiology at the Yale School of Public Health, told NPR.

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, in many countries, the BA.2 has begun to spread faster.

The original version of Omicron had specific genetic features that allowed health officials to rapidly differentiate it from Delta using a certain PCR test because of what’s known as “S gene target failure”.

BA.2 doesn't have this same genetic quirk.

A person with BA.2 will still test positive