Dozens of mammals could be susceptible to SARS-CoV-2

Tuesday, 13 October 2020

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Numerous animals may be vulnerable to SARS-CoV-2, the virus that causes Covid-19, according to a large study modelling how the virus might infect different animals’ cells, involving Oxford Brookes University academics.

The study which was led by UCL and published in Scientific Reports reports evidence that 26 animals regularly in contact with people may be susceptible to infection.

The researchers investigated how the spike protein from SARS-CoV-2 could interact with the ACE2 protein it attaches to when it infects people.

The focus of the investigation was whether mutations in the ACE2 protein in 215 different animals, that make it different from the human version, would reduce the stability of the binding complex between the virus protein and host protein. Binding to the protein enables the virus to gain entry into host cells; while it is possible the virus might be able to infect animals via another pathway, it is unlikely based on current evidence that the virus could infect an animal if it cannot form a stable binding complex with ACE2.

This research is an early indicator that it may be necessary to adopt enhanced hygiene measures when working with some animals, in order to reduce the risk of transmission.

Jon Lees, Senior Lecturer in Bioinformatics, Oxford Brookes University

The researchers found that for some animals, such as sheep and great apes (chimpanzee, gorilla, orangutan, and bonobo, many of which are endangered in the wild), the proteins would be able to bind together just as strongly as they do when the virus infects people, although that does not confirm that the animal can indeed be infected.

Co-author of the paper, Jon Lees (Senior Lecturer of Bioinformatics, Oxford Brookes University) said:  “What we don’t yet know is how severely these animals could be infected by SARS-COV-2, but our work sets out a framework for helping to guide future research on this.

“However, this research is an early indicator that it may be necessary to adopt enhanced hygiene measures when working with some animals, in order to reduce the risk of transmission.

“Additionally, in order to protect animals, monitoring animals for the virus, for example on farms or areas of conservation, could be needed to catch cases early on.

“Because our approach is computational we think our methods could be of use for future viral pandemics, which are unfortunately likely to occur due to our poor stewardship of the natural world, relating to habitat destruction and wildlife markets.”

Lead author Professor Christine Orengo (UCL Structural & Molecular Biology) said: “We wanted to look beyond just the animals that had been studied experimentally, to see which animals might be at risk of infection, and would warrant further investigation and possible monitoring.

“The animals we identified may be at risk of outbreaks that could threaten endangered species or harm the livelihoods of farmers. The animals might also act as reservoirs of the virus, with the potential to re-infect humans later on, as has been documented on mink farms."

The research team also performed more detailed structural analyses for certain animals, to gain a better understanding of how infection risks may differ across animal species. By comparing their findings to other experimental data, they set thresholds to predict which animals are at risk of infection, and which ones most likely cannot be infected.

They found that most birds and reptiles do not appear to be at risk of infection, but the majority of the mammals they reviewed could potentially be infected.

The team’s findings mostly agree with experiments conducted in living animals and with reported cases of infections. They predict possible infection in domestic cats, dogs, mink, lions, and tigers, all of which have had reported cases, as well as ferrets and macaques, which have been infected in laboratory studies. The researchers also identified other animals that may be susceptible to the virus, which have not yet been studied with infection tests, such as sheep.

First author, Su Datt Lam (UCL Structural & Molecular Biology and the National University of Malaysia) said: “Unlike laboratory-based experiments, the computational analyses we devised can be run automatically and rapidly. Therefore, these methods could be applied easily to future virus outbreaks that, unfortunately, are becoming more common due to human encroachment into natural habitats."

The study was conducted by researchers in UCL Biosciences, UCL Science & Technology Studies, National University of Malaysia, King’s College London, and Oxford Brookes University, and was supported by Wellcome, the Newton Fund UK-China NSFC initiative, BBSRC, EDCTP PANDORA-ID NET, NIHR UCLH/UCL Biomedical Research Centre, and the Medical Research Council.