Omicron coronavirus strain spreading significantly faster than Delta -WHO

Omicron is spreading rapidly in countries with high levels of population immunity, but it is unclear if this is due to the virus' ability to evade immunity, its inherent increased transmissibility.

 At a free drive-through coronavirus disease (COVID-19) vaccine clinic run by the Jamestown S'Klallam Tribe in Sequim (photo credit: REUTERS/LINDSEY WASSON)
At a free drive-through coronavirus disease (COVID-19) vaccine clinic run by the Jamestown S'Klallam Tribe in Sequim
(photo credit: REUTERS/LINDSEY WASSON)

The Omicron coronavirus variant has been reported in 89 countries and the number of cases is doubling in 1.5 to 3 days in areas with community transmission, the World Health Organization (WHO) said on Saturday.

Omicron is spreading rapidly in countries with high levels of population immunity, but it is unclear if this is due to the virus' ability to evade immunity, its inherent increased transmissibility or a combination of both, the WHO said in an update.

The agency designated Omicron a variant of concern on Nov. 26, soon after it was first detected, and much is still not known about it, including the severity of the illness it causes.

"There are still limited data on the clinical severity of Omicron," the WHO said. "More data are needed to understand the severity profile and how severity is impacted by vaccination and pre-existing immunity."

Syringes with needles are seen in front of a displayed stock graph and words ''Omicron SARS-CoV-2'' in this illustration taken, November 27, 2021. (credit: REUTERS/DADO RUVIC/ILLUSTRATION/FILE PHOTO)
Syringes with needles are seen in front of a displayed stock graph and words ''Omicron SARS-CoV-2'' in this illustration taken, November 27, 2021. (credit: REUTERS/DADO RUVIC/ILLUSTRATION/FILE PHOTO)

It added, "There are still limited available data, and no peer-reviewed evidence, on vaccine efficacy or effectiveness to date for Omicron".

The WHO warned that with cases rising so rapidly, hospitals could be overwhelmed in some places.

"Hospitalizations in the UK and South Africa continue to rise, and given rapidly increasing case counts, it is possible that many healthcare systems may become quickly overwhelmed."