The scientists who proposed that the COVID-19 Omicron variant had emerged in a broad range across Africa months before it was first detected in the south of the continent have retracted their paper, admitting that their samples were contaminated.
First identified in Botswana and South Africa in November 2021, the Omicron strain has since quickly spread across the world and become the most dominant variant of the virus. It’s unclear where Omicron actually first emerged. It could be that the two countries first spotted it because they have better genetic sequencing networks than their neighbors.
The question of where exactly Omicron’s predecessors were lurking still puzzles scientists. The highly transmissible strain’s closest-known genetic ancestor dates back to some time after mid-2020, meaning that it had generated all its unusual mutations completely without detection—despite unprecedented global efforts in genomic surveillance of the virus for more than a year….