WHO Is Tracking Omicron BA.4 and BA.5 Subvariants

WHO Is Tracking Omicron BA.4 and BA.5 Subvariants
WHO Is Tracking Omicron BA.4 and BA.5 Subvariants

Omicron subvariants BA.4 and BA.5 are circulating at low levels in several countries within Southern Africa and Europe, according to the World Health Organization.

The two subvariants of the highly contagious Covid-19 strain have been detected in Botswana, South Africa, Germany and Denmark, among other countries, WHO’s technical lead on Covid-19 Maria Van Kerkhove said, CNBC reported on Friday.

BA.4 and BA.5 don’t appear to be more contagious or deadly than the original omicron mutation so far, but that could change as more cases are detected, she added.

Van Kerkhove emphasized the need to maintain “robust” genome surveillance systems that will allow countries to track and analyze the two subvariants as well as earlier versions of omicron.

“It is still early days. What we have to make sure is that we continue to have the ability to track, the ability to share and the ability to analyze so that we can answer questions like this,” Van Kerkhove said Thursday during a WHO briefing that was live-streamed on the organization’s social media platforms.

Her remarks come days after the WHO said it was tracking a few dozen cases of BA.4 and BA.5, in addition to earlier omicron variants such as BA.1, BA.2, BA.3 and BA.1.1.

It also comes as the more contagious BA.2 subvariant advances across several parts of the world, fueling a new wave of Covid cases after the unprecedented surge caused by the original omicron variant, BA.1, during the winter.

BA.2 is now the dominant strain globally. In the US, making up about 85% of sequenced new cases and is even more dominant in the northeast region of the country where it represents about 92% of newly sequenced cases, according to data from the Centers for Disease Control and Prevention.

The earliest BA.4 sample was collected in South Africa on Jan. 10, but data shows that the “accumulation of genomes” and geographic spread of the subvariant is more recent, according to a report from UK’s Health Security Agency released last week.  

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