SARS-CoV-2 Can Infect Mammals Too

Humans are not the only species facing a potential threat from the SARS-CoV-2 coronavirus, according to a new study published by the University of California, Davis, on August 21, 2020. These scientists used genomic analysis to compare the main cellular receptor for the virus in humans — angiotensin converting enzyme-2 (ACE2) — in 410 different species of vertebrates, including birds, fish, amphibians, reptiles, and mammals.

They designed a 5-category binding score based on the conservation properties of 25 amino acids important for the binding between ACE2 and the SARS-CoV-2 spike protein. Only mammals fell into the medium to very high categories and only catarrhine primates (monkeys) into the very high category. Domestic animals such as cats, cattle, and sheep were found to have medium risk, and dogs, horses, and pigs were found to have a low risk for ACE2 binding.

Extending this analysis to human population data, these researchers found only rare (frequency <0.001) variants in 10/25 binding sites.