This is a summary, written by members of the CITF Secretariat, of:

Griffin BD, Chan M, Tailor N, Mendoza EJ, Leung A, Warner BM, Duggan AT, Moffat E, He S, Garnett J, Tran KN, Banadyga L, Albietz A, Tierney K, Audet J, Bello A, Vendramelli R, Boese AS, Fernando L, Lindsay LR, Jardine CM, Wood H, Poliquin G, Strong JE, Drebot M, Safronetz D, Embury-Hyat C, Kobasa D. SARS-CoV-2 infection and transmission in the North American deer mouse. Nat Commun. 2021 Jun 14;12:3612. doi: 10.1038/s41467-021-23848-9.

The results and/or conclusions contained in the research do not necessarily reflect the views of all CITF members.

SARS-CoV-2 was observed to infect many mammals, including deer mice, one of the most prevalent types of rodents in North America. Scientists working at the Public Health Agency of Canada’s National Microbiology Laboratory, including CITF Testing Working Group members Heidi Wood, Guillaume Poliquin, and Michael Drebot, recently published findings in Nature Communications indicating that deer mice can be infected by SARS-CoV-2 in the lab, and that they can transmit the virus to non-infected cage mates. These findings are promising because they indicate that these deer mice may be a suitable animal model to study the COVID-19 disease as they are likely to reflect the outcomes of infection observed in humans.

Key points:

  • Deer mice as small animal model: These mice have a lifespan that is four times that of other small laboratory animals, including Syrian hamsters and laboratory mice. These mice are not inbred and are more likely to reflect the diverse outcomes of infection observed in humans. This provides an opportunity to study the effects of age and immunity in the context of SARS-CoV-2.
  • Infection and disease in deer mice: Young deer mice were susceptible to intranasal SARS-CoV-2 infection when administered with the virus isolated from humans. The authors recorded virus replication in the upper and lower respiratory tract, though with little or no signs of disease. Infectious virus was detectable in nasal washes, throat and rectal swabs, and viral RNA – not necessarily always infectious – was detectable in feces and occasionally urine. A SARS-CoV-2-specific immune response, with antibodies and inflammatory molecules, was also detected.
  • Transmission among deer mice: The infected mice were able to transmit the virus to other non-infected mice through direct contact when animals were kept within the same cages.