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A new and potentially more transmissible coronavirus variant first identified by South African scientists has prompted a fresh round of travel restrictions across the world and raised concern about what may be next in the pandemic.
The strain, named Omicron, was designated Friday as a variant of concern by the World Health Organization, which said studies of it are underway as advisers continue to monitor it.
While scientists say there is reason to be concerned over Omicron, they stress there is still a lot we don't know -- including whether the variant is indeed more contagious, whether it causes more severe disease or what its effects on vaccine efficacy may be.
