A subvariant of the highly transmissible Omicron coronavirus strain, which was first identified in Denmark has now been detected in 57 countries, the WHO said on Tuesday.

In its weekly epidemiological update, the World Health Organization said that the Omicron variant, which accounts for over 93 percent of all coronavirus specimens collected in the past month, counts several sub-lineages: BA.1, BA.1.1, BA.2 and BA.3.

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

The BA.2 subvariant has begun  to replace Omicron's more common "original" BA.1 subvariant in countries such as Denmark.

Vaccines continue to provide similar protection against the different forms of Omicron, Dr. Boris Pavlin of the WHO's COVID-19 Response Team told an online briefing.