The virus that causes Covid-19, SARS-CoV-2, is zoonotic — meaning it can be both carried and transmitted by animals.
New findings reveal which animals are most and least at-risk for the virus behind the ongoing global pandemic.
In a new genomic analysis, researchers compared 252 mammal species to gauge how likely they are to become infected with SARS-CoV-2. To do this, they studied a specific cellular receptor, the ACE-2 enzyme, which is one of the key factors needed for a virus to bind to and enter a cell.
The researchers also looked at birds, reptiles, fish, and amphibians, analyzing 410 vertebrate species in all. But only mammals fall into the medium to very high risk categories — and only primates fall into the highest-risk category. That suggests those species — humans included — are at highest risk for SARS-CoV-2 infection, the researchers say.
Here is how some of the mammal findings break down:
Very high risk:
Very low risk:
The animals were compared with humans to determine their risk. Within humans’ ACE-2 receptors, 25 amino acids are needed for the SARS-CoV-2 spike protein to bind to cells. The researchers theorize that an animal’s risk level depends on how much that animal differs from humans.
The new study was published on August 21 in the journal Proceedings of the National Academy of Sciences.
Animal risks — In all, roughly 40 percent of the species potentially at risk for SARS-CoV-2 are also classified as “threatened” by the International Union for Conservation of Nature, the authors report.
The link may not be a coincidence.
Previous research has gotten into the reasons behind why some animals are more susceptible to viruses than others.