New Delhi: Amid the unabated spread of the Omicron cases around the world, the World Health Organization (WHO) has said infection numbers of the new variant is doubling at least every 3 days.

The new variant of the coronavirus is spreading faster than the Delta strain in countries with documented community transmission, with the number of cases doubling in 1.5 to 3 days, according to the WHO.

As of December 16, the Omicron variant has been identified in 89 countries across all six WHO regions. The current understanding of the Omicron variant will continue to evolve as more data becomes available.

In an update on Saturday, the United Nations’ health agency said that there is consistent evidence that Omicron has a substantial growth advantage over Delta.

“It is spreading significantly faster than the Delta variant in countries with documented community transmission, with a doubling time between 1.5-3 days. Omicron is spreading rapidly in countries with high levels of population immunity and it remains uncertain to what extent the observed rapid growth rate can be attributed to immune evasion, intrinsic increased transmissibility or a combination of both,” WHO said.

However, given the currently available data, it is likely that Omicron will outpace Delta where community transmission occurs.

The UN agency added that there are still limited data on the clinical severity of Omicron. More data are needed to understand the severity profile and how severity is impacted by vaccination and pre-existing immunity, it added.

According to WHO, 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.

There are still limited available data, and no peer-reviewed evidence, on vaccine efficacy or effectiveness to date for Omicron, the UN agency said.