Stealth Omicron: What we know about the new Covid subvariant sneaking into countries

People queue for a COVID-19 test in Times Square as the Omicron coronavirus variant continues to spread in Manhattan, New York City. (File)

A subvariant of Omicron has been rapidly spreading in the US, parts of Europe and some parts of Asia that has been dubbed ‘stealth Omicron’ because it is difficult to detect. The new subvariant has been categorised under Omicron as BA2 for now.

Subvariant BA2 appears to be transmissible than BA1, the World Health Organisation has said adding that even though there is a spike in sequences in the new subvariant, global cases of all coronavirus variants have declined.

Although called a variant of concern, WHO has said the new subvariant will be categorized under Omicron and should not yet be considered to be a separate variant.

“BA.2 differs from BA.1 in its genetic sequence, including some amino acid differences in the spike protein and other proteins. Studies have shown that BA.2 has a growth advantage over BA.1. Studies are ongoing to understand the reasons for this growth advantage, but initial data suggest that BA.2 appears inherently more transmissible than BA.1, which currently remains the most common Omicron sublineage reported. This difference in transmissibility appears to be much smaller than, for example, the difference between BA.1 and Delta,” WHO said in a statement explaining the differences between Omicron and the new subvariant.

White House Chief Medical Advisor Dr Anthony Fauci, a top expert in the Covid-19 disease, has also said the subvariant may account for around 30 percent of all new infections in the US. It is currently the most dominant variant in the country as well.

Fauci, speaking on ABC network, said that vaccines and booster shots will help prevent serious illness adding that even if the virus is not as severe, it may cause a worrying uptick in cases in the US in the coming months.

While Omicron is highly transmissible, the disease has not been severe so far. However, the new subvariant is being detected frequently. WHO said they will be monitoring the subvariant closely.