At a time when scientists across the world are scrambling to determine the true impact of the Omicron, the World Health Organization on Wednesday warned that the highly mutated variant of Covid-19 could change the course of the pandemic.
The WHO's remark comes at a time when the Omicron variant, first identified in southern Africa, has been found in 57 countries across the world.
At a media briefing from the group's Geneva headquarters, WHO Director-General Tedros Adhanom Ghebreyesus said that the exact impact is "still difficult to know."
"Certain features of omicron, including its global spread and large number of mutations, suggest it could have a major impact on the course of the pandemic," Tedros said.
Noting that we can prevent Omicron from becoming a global crisis, the WHO chief called on countries to vaccinate as fast as possible and keep measures in place to protect people from infection.
"This virus is changing, but our collective resolve must not."
The organization also said while there's early evidence that omicron is milder than the delta strain, it's too early to be definitive.
Meanwhile, US infectious diseases expert Anthony Fauci on Tuesday echoed an assurance that Omicron is certainly not worse than the previous strains, including Delta.
According to the chief medical advisor to the US president, Omicron is "clearly highly transmissible" but might actually be less severe than Delta, as indicated by the ratio between the number of infections and the number of hospitalisations in South Africa.
Earlier on Wednesday, Pfizer and BioNTech said initial laboratory studies show a third dose of their vaccine may be needed to neutralize the omicron variant, an analysis that will accelerate booster-shot drives around the world.
The WHO has been pushing for countries to hold off on boosters to make more vaccines available to poorer countries where inoculation rates are low. But governments may be less likely to do that if evidence from tests continues to show that third shots are needed to protect against omicron.