SARS-CoV-2, the virus responsible for the COVID-19 pandemic, is not only still circulating among humans but is also infecting white-tailed deer in the United States, where it appears to be evolving more rapidly. While the origins of SARS-CoV-2 remain mysterious, the virus has demonstrated its ability to jump from humans to various other mammals, according to a recent study.
Researchers conducted this study by swabbing the noses of free-ranging deer in Ohio between November 2021 and March 2022. They collected samples from 1,522 deer across 83 of Ohio’s 88 counties. Genetic analysis of the swabs identified active SARS-CoV-2 infections in 10% of the deer, with at least one positive case found in 59% of the tested counties.
The study also examined blood samples from the deer to detect evidence of previous infections through the presence of specific antibodies. Based on these results, the researchers estimate that nearly 24% of deer in Ohio have been infected by SARS-CoV-2 at some point. Genomic analysis suggests that at least 30 of the active infections in deer were transmitted from humans.
This spill over between humans and deer is concerning, as white-tailed deer could serve as a reservoir for the virus, potentially spreading it to other wildlife, livestock, and humans. The study found that the virus was most prevalent near dense human populations but was also found in rural areas.
The study also detected the highly contagious delta variant in many of the deer, which was prevalent among humans in the US during the study period. There were also signs of the alpha variant. The genetic makeup of delta variants in deer matched those circulating among humans, indicating spill over events from humans to deer.
MORE RAPID IN DEER THAN HUMANS
Interestingly, SARS-CoV-2 appears to evolve more rapidly in deer than in humans, although the implications of this for human health remain unclear. However, the study suggests that COVID-19 vaccination offers protection against variants from deer.
While the variants from deer may not pose an immediate threat to humans, they could potentially impact domesticated animals or other wildlife. About 70% of free-ranging white-tailed deer in Ohio have not been exposed to SARS-CoV-2, raising concerns about the trajectory of the virus in this population and its potential to infect other animal hosts.
The study highlights the importance of continued monitoring and research to better understand the dynamics of SARS-CoV-2 in wildlife and its potential implications for human and animal health.