Comparative Assessment of Severe Acute Respiratory Syndrome Coronavirus 2 Variants in the Ferret Model

Abstract

Continued surveillance and risk assessment of emerging SARS-CoV-2 variants are critical for pandemic response and preparedness. As such, in vivo evaluations are indispensable for early detection of variants with enhanced virulence and transmission.

Detection of Airborne Influenza A and SARS-CoV-2 Virus Shedding following Ocular Inoculation of Ferrets

“…WA/1 and Delta SCOV2 strains were previously shown to transmit efficiently in a ferret DCT model following i.n. inoculation ( 26 ); comparable transmissibility with the two viruses was detected following o.c. inoculation, despite a 1- to 2-day delay in infectious virus detection in contact animals relative to donor animals inoculated intranasally ( Fig.…”

“…We recently found that SCOV2 RNA could be detected sporadically in ferret CW specimens following i.n. inoculation ( 26 ), but the capacity of SCOV2 to cause infection following ocular exposure in ferrets was not known. Employing the same experimental design as described above, ferrets were inoculated by the o.c.…”

“…route shed peak mean titers of 3.7 and 4.6 log 10 viral RNA copies/L of air, or 6.1 and 6.6 log 10 viral RNA copies over the course of an hour, respectively; these quantities were indistinguishable from those from ferrets inoculated by the i.n. route ( 26 ). Collectively, like IAV, SCOV2 strains led to a productive and transmissible infection in ferrets following o.c.…”

“…Furthermore, ocular specimens have been only rarely collected from intranasally (i.n.) inoculated animals ( 24 – 26 ), limiting our understanding of how SCOV2 disseminates to ocular tissues and the degree to which IAV and SCOV2 may differ in this ability.…”

“…with two IAV and two SCOV2 strains previously shown to replicate efficiently following intranasal (i.n.) inoculation ( 26 , 33 , 34 ). Following inoculation, we examined virus pathogenicity, transmissibility, aerosolized virus shedding profiles, and emergence of variant virus populations during the course of infection.…”