Experimental infections of H5N1 influenza in ferrets

Outbreaks of highly pathogenic H5N1 clade 2.3.4.4b viruses in farmed mink and seals combined with isolated human infections suggest these viruses pose a pandemic threat. To assess this threat, we evaluated an H5N1 isolate derived from mink in the ferret model. We performed experimental infections using viral isolates with and without the PB2 T271A adaptive mutation, measuring mortality and airborne transmission in exposed ferrets.