A new version of the coronaviruses has been found in white-tailed deer in southwestern Ontario, and may have been evolving in animals since late 2020.

The first evidence of deer-to-human transmission of the virus was found in a person who had close contact with deer.

The virus is evolving in deer and diverging in deer away from what we are seeing in humans, according to an author of a new paper.

The report has not yet been published in a peer-reviewed journal, and there is no evidence that the deer lineage is spreading among people. Preliminary laboratory experiments show that the lineage is unlikely to evade human antibodies.

The paper was posted online just days after another team reported that the Alpha variant may have continued to spread and evolve in Pennsylvania deer even after it disappeared from human populations.

The risk that deer could become a long-term source of future variants of the virus is raised by the two studies.

There is no need to panic, according to Arinjay Banerjee, who was not involved in either study.

The more hosts you have, the more opportunities the virus has to evolve.

White-tailed deer have been found to have the virus. Humans have introduced the virus to deer and then transmitted it to each other, according to research. There is no evidence that deer are passing on the virus to humans.

More than two dozen researchers collaborated on the Canada study. There were 300 white-tailed deer killed by hunters in Ontario between November 1 and December 31, 2021. Six percent of the animals from southwestern Ontario tested positive for the virus, suggesting that they were exposed to it when they died.

The researchers found a unique constellation of changes in the viral genomes of five deer that had not been previously documented. The original version of the virus was set apart from the 76 different variations by some of them.

The deer samples were related to viral samples taken from human patients in Michigan in November and December of 2020. They were similar to samples taken from humans in Michigan.

The new lineage may have been evolving undetected since late 2020 and may have deviated from known versions of the virus.

A researcher swabbing a deer at a wildlife center at Texas A&M University in College Station.
ImageA researcher swabbing a deer at a wildlife center at Texas A&M University in College Station.
A researcher swabbing a deer at a wildlife center at Texas A&M University in College Station.Credit...Sergio Flores for The New York Times

Its path is not clear. Humans might have passed the virus to deer, and the virus then spread among the cervids. It is possible that the lineage evolved in another, intermediate species, which then transmitted it to deer.

We don't have all the pieces in the puzzle, according to Dr. Kuchipudi, who was not involved in the research.

The deer samples were close to the viral sample collected from one human patient. The person is known to have had close contact with deer.

For privacy reasons, they could not give more information about the nature of this contact.

There is no proof that the person caught the virus from deer, and there is not enough information to confirm it.

At the time the human sample was collected, Ontario was analyzing the samples from everyone who tested positive for P.C.R. The researchers did not find any other people who had been exposed to the same version of the virus.

Had it been circulating widely in humans, I think we would have picked it up.

There is no evidence that the person with the virus passed it on to anyone else.

Early data shows that existing vaccines can still protect against the lineage. The scientists found that people who had been vaccined were able to destroy pseudoviruses that had been engineered to look like deer.

In the second study, scientists from the University of Pennsylvania's veterinary and medical schools analyzed nasal swabs from 93 deer that died in Pennsylvania in the fall and winter of 2021. Nineteen percent of them were active with the virus. Five of the deer were found to have the Delta variant, while two were found to have the Alpha variant.

The Alpha wave that hit Americans in the spring of 2021 had faded by the time the samples were collected.

Eman Anis, a microbiologist at the University of Pennsylvania School of Veterinary Medicine, said that alpha seems to persist in the white-tailed deer even when it isn't circulating in humans.

The Delta samples in deer were similar to those from humans, suggesting that it had crossed species lines recently. The two Alpha sequences were different from the human ones. The variant had been introduced to the deer population at least twice, and they were substantially different from each other.

The main implication would be that deer transmit infections within their populations.

It is not known whether the deer lineages will continue to evolve or if they will pose a risk to humans and other animals.

According to current information, the risk of wildlife, including deer, spreading the virus to people is low, according to a research scientist at the Ontario Ministry of Northern Development, Mines, Natural Resources.

Scientists said that ongoing monitoring is critical. Dr. Mubareka suggested that officials in Ontario and other nearby regions should look for deer in the wastewater to make sure that it isn't becoming more prevalent.

Public health agencies have guidelines for people to follow, including not feeding deer or other wildlife and wearing gloves while butchering game.

Dr. Mubareka said that we should reduce the biggest source of the virus, which is us.