Explained: What is the new Omicron BA. 2 variant, and how bad is it?

The BA.2 sub-lineage of the Omicron variant now makes up nearly a quarter of new Covid-19 infections in the US, according to the latest data of the US Centers for Disease Control and Prevention (CDC).

The virus, known as BA.2, is a strain of the highly contagious omicron variant that appears to spread even more easily — about 30% more easily.

“The BA. 2 descendant lineage, which differs from BA. 1 in some of the mutations, including in the spike protein, is increasing in many countries,” the WHO wrote on its website. “Investigations into the characteristics of BA. 2, including immune escape properties and virulence, should be prioritized independently (and comparatively) to BA. 1.”

Scientists are keeping close watch on the BA.2 strain of the Omicron variant that has quietly spread throughout the United States.

BA.2 has now been detected in more than 30 states, makes up around 3.9 per cent of new infections, and appears to be doubling quickly, according to the Center for Disease Control and Prevention’s data tracker.

BA. 2 has been detected in India, Denmark and Britain, among other countries, according to health officials and media reports abroad. In Europe, it appears the most widespread in Denmark, but that may be because the Scandinavian nation has a robust program of sequencing the virus’s genome.

Although vaccination and prior infection does appear to protect people against BA.2, this version of the virus seems somewhat better at evading the immune system than the original omicron was. This increases the concern that it could drive a growth in new cases.

With inputs from agencies