The Omicron covid strain could hardly have accumulated so many mutations when developing only in the human population. This is evidenced by the results of research conducted by scientists from the Institute of Genetics and Developmental Biology of the Chinese Academy of Sciences.
According to experts, to obtain such a number of mutations, the Omicron covid strain had to "jump" first into mice and then back into humans. Chinese experts monitored the rate of accumulation of changes in a number of varieties of SARS-CoV-2. They found that the Omicron strain accumulated 27 mutations in 18 months. This is 3.3 times faster than the average of other variants of the virus, Izvestia reported.
"WBP-1 in mice reproduces pathogenic characteristics very similar to many of the clinical manifestations of coronavirus in humans, including morbidity, mortality, and pulmonary pathology," the researchers reported in their paper.
Specialists have identified that the Omicron progenitor could have passed from humans to animals, as the process would have required significant mutations in the spike to rapidly adapt to a new host. Scientists believe that the intermediate carrier of this strain was most likely a mouse.