Deer sampled on Staten Island, New York, over the same period showed evidence of spillover infection from humans by another COVID variant, omicron. Viral exchanges between communities and their deer are happening often.

Mutating three times faster in deer than in humans

By measuring changes in the COVID genomes in the deer using a new statistical method, the researchers in Ohio estimated that the rate of COVID mutation was three times greater than in humans. The types of genetic changes were not the same as those in human COVID. The mutations appeared to be adaptive responses that might have increased viral spread in its new deer hosts.