There is a vital need for authentic COVID-19 animal models to enable the pre-clinical evaluation of candidate vaccines and therapeutics. Here we report a dose titration study of SARS-CoV-2 in the ferret model. After a high (5 × 10 6 pfu) and medium (5 × 10 4 pfu) dose of virus is delivered, intranasally, viral RNA shedding in the upper respiratory tract (URT) is observed in 6/6 animals, however, only 1/6 ferrets show similar signs after low dose (5 × 10 2 pfu) challenge. Following sequential culls pathological signs of mild multifocal bronchopneumonia in approximately 5–15% of the lung is seen on day 3, in high and medium dosed groups. Ferrets re-challenged, after virus shedding ceased, are fully protected from acute lung pathology. The endpoints of URT viral RNA replication & distinct lung pathology are observed most consistently in the high dose group. This ferret model of SARS-CoV-2 infection presents a mild clinical disease. SARS-CoV-2 induces mild infection in ferret model. Here, Ryan et al. characterise optimal infection dosage inducing upper respiratory tract (UTR) viral shedding, progression time of viral shedding, and pathology in ferrets and finally provide evidence for protection after re-challenge.
【저자키워드】 SARS-CoV-2, Infection, 【초록키워드】 COVID-19, pathology, High dose, Therapeutics, SARS-COV-2 infection, viral shedding, lung, animal model, progression, virus, Replication, Viral, Virus shedding, ferret, low dose, Mild, Viral RNA, respiratory, URT, UTR, upper respiratory tract, mild infection, Lung pathology, Evidence, endpoints, dose, bronchopneumonia, Viral RNA shedding, Endpoint, medium, dosage, candidate vaccine, ferrets, clinical disease, intranasally, induce, groups, dosed, pfu, 【제목키워드】 protective immunity, Evidence, infection with SARS-CoV-2,