Rhesus macaques and cats as potential spillback reservoirs for SARS-CoV-2
In these experiments, the researchers found that the in vitro results agreed well with previously published studies using animal experimentation to assess the susceptibility of different animals to SARS-CoV-2 infection. Using whole viral genome sequencing, the researchers also observed that SARS-CoV-2 replicated in the in vitro models of monkey and cats, without the need for the virus to adapt. These findings suggest that certain species of monkeys and cats may be particularly vulnerable to SARS-CoV-2 infection. "Our findings, together with the reports from previously documented spillover events, indicate that close surveillance of these animals and other close relatives, whether they live in the wild, captivity or households, is necessary", says Dijkman.
This information can be used by the responsible authorities such as the Swiss Federal Office for Public Health and the Federal Food Safety and Veterinary Office, for SARS-CoV-2 surveillance at the human – animal interface. Specifically, it helps them to establish and tailor early detection surveillance programs to monitor animals that can act as potential spillback reservoirs for SARS- CoV-2. Dijkman added, “This will benefit the general public since it will help prevent new SARS- CoV-2 variants from developing in animal reservoirs and potentially being reintroduced into the human population, to which the current vaccines may not be protective.”
Implementing the 3R (Replace, Reduce, Refine) principles in coronavirus research
The findings of the study also show that advanced in vitro cell culture models of cells lining the airways from different mammals can be used as an alternative method, circumventing traditional in vivo experimental constraints, to evaluate and provide insight into the host spectrum of SARS-CoV- 2. “Our study shows that there is a lot of potential to replace, reduce and refine animal experimentation in the near future, and I hope that for basic fundamental research questions our results will convince researchers, pharmaceutical companies, and drug administration agencies to use advanced biologically relevant in vitro models prior to conducting animal experiments”, says Dijkman.
This work was supported by the European Commission (Marie Sklodowska-Curie Innovative Training Network “HONOURS”), the Swiss National Science Foundation SNSF (Special call on Coronaviruses), the German Federal Ministry of Education and Research, and the Swiss Federal Food Safety and Veterinary Office (BLV).