7 Apr 2022
Research led by The Pirbright Institute finds variants alpha, beta and delta can infect more species, such as rodents and ferrets, compared to the ancestral virus strain.
Paul Imrie
Job Title
Scientists have discovered variants of the virus causing COVID-19 can potentially infect more animal species than the original strain.
In a study led by The Pirbright Institute, SARS-CoV-2 variants alpha, beta and delta were found to infect more species, such as rodents and ferrets, compared to the ancestral virus strain, due to the mutations in its genetic code.
Although still to be confirmed, SARS-CoV-2 is suspected to have come from an animal reservoir – potentially bats – when it emerged in Wuhan in late 2019, and it has since been reported in mink, deer and cats.
Research published in The Journal of General Virology looked at SARS-CoV-2 variants of concern to allow scientists to understand their ability to enter cells in different animal species.
It uses spike proteins found on the surface of the virus to bind a receptor on the host cell – angiotensin-converting enzyme 2 (ACE2) – and this allows the virus to enter the host cell and replicate to cause disease.
ACE2 receptors in a range of species – including mice, rats, hamsters, ferrets, civets and pigs – were tested with spike proteins from variants of concern. The results demonstrated changes in the proteins allowed the virus to enter the host cells and infect a wider range of species.
Scientists say this knowledge could be crucial because it allows them to predict animals that could become infected with SARS-CoV-2 – and could pose future risk to animals and humans.
It could also allow scientists to develop animal models of COVID-19 to help inform future disease treatment and prevention strategies.
Dalan Bailey, head of Pirbright’s viral glycoproteins group, said: “It is really important to understand the mechanism of how SARS-CoV-2 gains entry to cells to make sure we’re using the right animal models when testing in the lab.
“Our results support the current models being used, but it’s important to know that you’re using the right species. Variants of the virus need to adapt when they reach new species and improving our understanding of what those adaptations are is helpful.
“But it’s not the whole story. The entry into the cell is just one step. Some species with cells allow virus entry, but not replication or infection. That is harder to understand, and the G2P Consortium [a national research project studying emerging variants of SARS-CoV-2] is working together to try to figure out why that is.”
Wendy Barclay – co-author of the paper and head of the Department of Infectious Disease and medical research chairperson at Imperial College, London – spoke at the Microbiology Society Conference (4 to 7 April) and said collaboration was essential to advance scientific knowledge.
She said: “I think one of the only good things to come out of the COVID-19 pandemic is that people really have worked together… People working together is going to be essential for those rapid responses we need.”
The paper, “SARS-CoV-2 variants of concern alpha, beta, gamma and delta have extended ACE2 receptor host ranges”, is available online.
