The number of cases of the Omicron variant of COVID-19 is doubling rapidly in countries with high levels of population immunity, according to a statement on Saturday by the World Health Organization (WHO).
The variant has been reported in 89 countries in all six of the agency’s regions around the world, the WHO said.
In the State of Israel, as of Saturday there were 134 verified cases of the variant.
“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. However, given current available data, it is likely that Omicron will outpace Delta where community transmission occurs.
It is unclear, however, whether the high rate of transmission is due to Omicron’s inherent increased transmissibility, or an ability by the virus to evade immunity, the agency said. It might also be due to a combination of those factors.
There are still limited data on the clinical severity of Omicron, the WHO added.
“More data are needed to understand the severity profile and how severity is impacted by vaccination and pre-existing immunity,” the agency said, adding that it is possible that many healthcare systems may become quickly overwhelmed.
The Omicron variant was designated a “variant of concern” on November 26, and in less than a month it has spread worldwide, including to the State of Israel.
“There are still limited available data, and no peer-reviewed evidence, on vaccine efficacy or effectiveness to date for Omicron. . . “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.”
Therapeutic interventions for the management of patients with severe or critical COVID-19 associated with the Omicron variant that target host responses (such as corticosteroids, and interleukin 6 receptor blockers) are expected to remain effective, the agency noted, but added a warning that preliminary data from preprint publications suggest that some of the monoclonal antibodies developed against SARS-CoV-2 may have decreased neutralization against Omicron.
Globally, as of Friday there were 271,963,258 confirmed cases of COVID-19, including 5,331,019 deaths reported to the WHO. Of those, nearly 100 million (99,115,289) cases were reported in North, Central and South America – including nearly 50 million in the US alone (49,833,416). Slightly fewer – 93,603,988 – cases were reported in Europe. In the Eastern Mediterranean region, 16,970,719 cases were reported.