The omicron variant of Covid-19, first identified in South Africa, has been detected in locations from Australia to Germany and Canada, showing the difficulties of curtailing new strains.
Most infections stem from travelers carrying the disease across borders. Israel, for instance, said a confirmed case who arrived from Malawi rode on a bus from Tel Aviv. Italy’s first case traveled around the country for days before testing positive.
Researchers worldwide are racing to understand the full impact of the new strain, and governments have banned travelers from South Africa and nearby countries on concerns omicron could evade the protection of