Highly transmissible Omicron sub-variant now in 57 countries, warns WHO

A sub-variant of the fast-spreading and heavily mutated Omicron strain of the coronavirus has now been detected in as many as 57 countries, warned the World Health Organisation (WHO) on Tuesday.

In what comes as a key cause for concern, some studies have indicated that this Omicron sub-variant could be even more infectious than the original version, which has rapidly become the dominant variant worldwide in only 10 weeks from when it was first detected in southern Africa.

The WHO, in its recent weekly epidemiological update, explained that Omicron, accounting for over 93 per cent of all coronavirus specimens collected in the past month, counts several sub-lineages: BA.1, BA.1.1, BA.2, and BA.3.

The BA.1 and BA.1.1, the very first Omicron sub-variants that were identified, still account for over 96 per cent of all the Omicron sequences uploaded to the GISAID global science initiative. However, there has since then been a clear rise in cases involving the BA.2 sub-variant, which counts several different mutations from the original – including one on the spike protein that dots the virus’s surface and is key to entering human cells.

“BA.2- designated sequences have been submitted to GISAID from 57 countries to date,” WHO said, adding that in some countries, the sub-variant now accounted for over half of all Omicron sequences gathered.

WHO admits that little is known right now about the complete extent of differences between all the sub-variants; however, detailed studies can reveal their characteristics – including transmissibility, immune evasion, and virulence.

Maria Van Kerkhove, one of the WHO’s top experts on Covid-19, told reporters yesterday that information about the sub-variant was very limited, but that some initial data indicated BA.2 had “a slight increase in growth rate over BA.1”.

Several recent studies have hinted that BA.2 is more infectious than the original Omicron.

Omicron, in general, is known to cause less severe disease than previous coronavirus variants, like Delta, that has wreaked havoc before. So far, there has been “no indication that there is a change in severity” with the BA.2 sub-variant, said Van Kerkhove.

However, she stressed though that regardless of the strain, Covid-19 remained a dangerous disease and people should strive to avoid catching it.

“We need people to be aware that this virus is continuing to circulate and that it is continuing to evolve,” she said. “It’s really important that we take measures to reduce our exposure to this virus, whichever variant is circulating.”