The knee-jerk response followed the news that the variant had an unusually high number of mutations, which scientists feared could make it more transmissible and result in immune evasion.

Much is still unknown about Omicron, including its origin, severity and its transmissibility. Researchers are also racing to discover if it could displace existing variants and become dominant, as Delta has.

Early "indications" show that people who have received the coronavirus vaccine booster are "protected" against the new variant, Israeli Health Minister Nitzan Horowitz said Tuesday.

This comes after anecdotal reports from South Africa suggested that most cases of the Omicron variant have been mild so far. But those South African cases were "mostly [among] young people anyway. So, I would say we just don't know [if the new variant causes more serious illness than previous strains]," Dr. Francis Collins, director of the National Institutes of Health, told CNN on Sunday.

Scientists say it will take weeks to unearth how dangerous the new variant is. But we do know that Omicron has been found in Europe, with cases of community transmission identified in earlier Covid-19 samples before the travel bans came into place.

Dutch health officials said Tuesday that Omicron was present in the Netherlands a week before two flights arrived from South Africa carrying the virus. At least one of the cases is thought to have been contracted in the Netherlands, RIVM virologist Chantal Reusken told national broadcaster NOS.

Nine cases of Omicron were linked to a private event on November 20 in Scotland, days before South Africa announced the existence of the variant. First Minister Nicola Sturgeon told Scottish Parliament Tuesday that none of the individuals had a recent travel history or known links to others who had traveled from southern Africa.

These cases have prompted some to question the need for the cascading travel restrictions, which has triggered a wave of resentment on the African continent. Many view the bans as another example of Africans bearing the brunt of hasty pandemic policymaking, which has seen rich countries hoarding vaccine doses and resources to the detriment of poorer nations.

"Excellent science should be applauded and not punished," South Africa's Foreign Ministry said Saturday, adding that the restrictions were "akin to punishing South Africa for its advanced genomic sequencing and the ability to detect new variants quicker."

"Putting in place travel bans that target Africa attacks global solidarity," the World Health Organization's (WHO) Regional Director for Africa Matshidiso Moeti said the following day. "Covid-19 constantly exploits our divisions. We will only get the better of the virus if we work together for solutions."