Age-Related Susceptibility of Ferrets to SARS-CoV-2 Infection
Mathias Martins, Maureen H. V. Fernandes, Lok R. Joshi, Diego G. Diel
Abstract
In humans, ACE2 and TMPRSS2 are expressed in various cells and tissues, and differential expression has been described in young and old people, with a higher level of expressing cells being detected in the nasal brushing of older people than young individuals. We described the same pattern occurring in ferrets, and we demonstrated that age affects susceptibility of ferrets to SARS-CoV-2. Aged animals were more likely to get infected when exposed to lower infectious dose of the virus than young animals, and the viral replication in the upper respiratory tract and shedding are enhanced in aged ferrets. Together, these results suggest that the higher infectivity and enhanced ability of SARS-CoV-2 to replicate in aged individuals is associated, at least in part, with transcription levels of ACE2 and TMPRSS2 at the sites of virus entry. The young and aged ferret model developed here may represent a great platform to assess age-related differences in SARS-CoV-2 infection dynamics and replication.