Covid-19: New Omicron sub-variant spreading fast; EMA calls for further studies to find distinctions

The BA.2 sub-variant of the coronavirus’ Omicron strain requires further study to understand how distinct it is from the original strain in terms of contagiousness and other factors, the European Medicines Agency Biological Health Threats and Vaccines Strategy chief Marco Cavaleri said.

Cavaleri said the Omicron variant was actively spreading across Europe and the world, while the BA.2 sub-variant was also present in several countries, Asian News International reported.

“It is too early to say to what extent this variant differs from Omicron in terms of transmissibility and immune invasion, noting however that it remains a closely related strain to Omicron,” Asian News International quoted Cavaleri as saying.

Denmark declared the BA.2 sub-variant, one of the Omicron variant’s three sub-strains, as dominant this week. GISAID, an international database tracking changes in the virus, reported that the subtype was first detected in The Philippines.

Experts speculate that the BA.2 sub-variant will become the predominant sub-strain in countries where it has been detected, outpacing the most common BA.1 subtype.

Reports suggest that Asia and Europe are reporting a sharp increase in cases driven by the BA.2 subtype.

While the BA.2 appears to have a higher transmissibility than previous sub-variants, there is no data that could suggest it causes severe disease.

So far, the Omicron variant has four lineages — BA.1, BA.2, BA.3, and B.1.1.529. The BA.1 subtype accounts for most of the cases with the World Health Organization (WHO) reporting that nearly 99% of viral DNA submitted to GISAID database as on 25 January to be identified as this sub-variant.

The BA.2 sub-variant has now been detected in 57 countries, the WHO said. In some countries, it accounts for over half the sequenced Omicron cases.

Denmark’s Statens Serum Institut said BA.2 infections rose to account for nearly half the country’s Covid-19 cases in January, according to reports.

In India also, the BA.2 subtype is rapidly replacing the Delta and BA.1 variants.