The coronavirus may be evolving in deer, two studies suggest.
Scientists have identified a new, heavily mutated version of coronavirus in white-tailed deer in southwestern Ontario, which may have been developing in animals since late 2020. They also found a very similar viral sequence in one person in the area who had close contact with deer, providing the first evidence of possible deer-to-human transmission of the virus.
“The virus develops in deer and diverges in deer, unlike what we clearly see in humans,” said Samira Mubareka, a virologist at the Sunnybrook Research Institute and the University of Toronto and author of the new paper.
The report has not yet been published in a peer-reviewed journal, and there is no evidence that the deer genus is spreading among humans or poses an increased risk to humans. Preliminary laboratory experiments suggest that this line is unlikely to escape human antibodies.
But the paper was posted online just a few days after the other team reported that the Alpha variant may have continued to spread and develop in Pennsylvania deer even after it disappeared from the human population.
Together, the two studies show that the virus can circulate in deer for long periods of time, raising the risk that the animals could become a long-term reservoir of the virus and a source of future variants.
“Of course, there is no need to panic,” said Arinjay Banerjee, a virologist at the University of Saskatchewan who was not involved in any of the studies.
But, he added, “the more hosts you have, the more opportunities for the virus to develop.”