The World Health Organization is tracking a few dozen cases of two new sub-variants of the highly transmissible Omicron strain of the coronavirus to assess whether they are more infectious or dangerous.
It has added BA.4 and BA.5, sister variants of the original BA.1 Omicron variant, to its list for monitoring. It is already tracking BA.1 and BA.2 – now globally dominant – as well as BA.1.1 and BA.3.
The WHO said it had begun tracking them because of their “additional mutations that need to be further studied to understand their impact on immune escape potential”.
Viruses mutate all the time but only some mutations affect their ability to spread or evade prior immunity from vaccination or infection, or the severity of disease they cause.
BA.2 now represents nearly 94% of all sequenced cases and is more transmissible than its siblings, but the evidence so far suggests it is no more likely to cause severe disease.
sub-variants a few dozen cases of BA.4 and BA.5 have been reported to the global GISAID database, according to WHO.
China is experiencing its largest wave of covid infections since the start of the pandemic, with Shanghai, a city of 25 million, currently under a citywide lockdown. On Sunday, China reported more than 13,000 new cases. Local authorities have said omicron subvariant BA.2 is behind the new outbreaks.
The UK has likewise identified a new subvariant of omicron it has called XE. According to the UK Health Security Agency (UKHSA), hundreds of people in the UK have so far been found to be infected with XE, a small fraction of total covid infections in the country. It is too early to tell if XE is more transmissible than other subvariants of omicron, though it has been detected beyond the UK, in Thailan
Source : This news is originally published by cgtn