The World Health Organization has released a report this week saying a new sublineage of the SARS-Cov-2 Omicron variant has already been detected in 57 countries. According to some researchers, the new version is more contagious than the original Omicron.
In its weekly epidemiological bulletin, the WHO said Omicron accounted for more than 93% of all coronavirus samples collected over the past month. The strain has several sublineages: BA.1, BA.1.1, BA.2 and BA.3. The rapidly spreading and mutating Omicron is now globally dominant after first being detected in southern Africa ten weeks ago, the WHO also said.
The WHO document also showed BA.1 and BA.1.1 - the earliest identified versions - continued to represent over 96% of the omicron sequences uploaded to the global Gisaid database, although the increase in the number of BA.2 cases was substantial.
“To date, 57 countries have submitted sequences designated BA.2 to Gisaid,” the WHO paper stressed. It also pointed out that, in some countries, that subvariant now accounted for more than half of the Omicron sequences collected, although little is still known about the differences among sublineages.
The WHO also called for studies to be carried out on the issue, particularly its transmissibility and its ability to evade immune protection, as well as its virulence. BA.2 is believed to be more contagious than the original Omicron.
WHO's Maria van Kerkhove said information on the subvariant was limited, although preliminary data showed BA.2 had a slightly increased growth rate compared to BA.1. She added there was no reason to fear BA.2 would be more dangerous than previous versions of Omicron, which generally cause a less severe illness than previous strains of the coronavirus.
The WHO also said deaths caused by Covid-19 had increased 9% worldwide last week, amid a sharp increase increase in Omicron cases. Deaths rose to 59,000 globally and new infections totaled 22 million. Total cases since the pandemic began two years ago have exceeded 370 million, while reported deaths are 5.6 million.
The weekly number of deaths from Covid-19 rose particularly in Southeast Asia and even worse in India (41%), followed by the Eastern Mediterranean region (32%) and the Americas (16%).