https://www.walesonline.co.uk/news/uk-news/scientists-think-now-know-omicron-22922361

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The dominant Omicron Covid variant is "most likely" to have come from mice, new research reveals.

Scientists now believe that it developed in mid-2020 in mice before reinfecting humans.

"We found that the Omicron variant contains mutations at five key sites of the protein: K417, E484, Q493, Q498, and N501.

"This mutation profile shows that the virus has adapted to infect the cells of mice.

"We believe that the coronavirus slowly accumulated mutations over time in mice before it was transmitted back to humans by reverse zoonotic.

"If Omicron is determined to have been derived from mice, the implications of it circulating among non-human hosts will pose new challenges in the prevention and control of the epidemic."

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If true it is a worrying prospect for those who are pursuing a "living with covid" path rather than a "living without covid" path.