Figure 4.

Onward transmission potential of donor ferrets coinoculated with BC (intranasally) and WT (intratracheally) A(H1N1)pdm09 viruses, in 2 independently repeated experimental groups (A, B). On day 2 postinoculation, 2 naive recipient ferrets were exposed to the exhaled breath of 1 inoculated donor ferret for 8 hours. All animals were single-housed in individually ventilated cages after exposure. Viral loads in the nasal washes (log₁₀TCID₅₀/mL) of donors (dark blue) and recipients (two shades of lighter blue) were determined at various time points to monitor transmission and viral shedding. The dotted line indicates the limit of detection at 1.789 log₁₀TCID₅₀/mL. Genotype percentage of WT (pink) and BC (blue) viruses in nasal washes were determined by NGS on peak titer days. Black lines indicate the mean sequence reads of each gene segment. Abbreviations: BC, barcoded; dpe, days postexposure; dpi, days postinoculation; NGS, next-generation sequencing; TCID₅₀, 50% tissue culture infectious dose; WT, wild type.