Fig. 1. The A/H1N1 virus was transmitted from the upper respiratory tract of ferrets.
Donor ferrets 1 and 2 were inoculated intranasally with 105 TCID50 of the A/H1N1 virus (shown in red) and intratracheally with 105 TCID50 of the A/H1N1var virus (shown in blue). Donor ferrets 3 and 4 were inoculated with the opposite placement of viruses. Recipient ferrets were added to the adjacent cage at 4 hpi. Virus titers in the nose and throat swabs were determined by TCID50 assay and are indicated on the y-axis. The limit of detection of the virus titration is shown by the dotted line. The proportions of untagged (red) and tagged (blue) viruses, as determined by next-generation sequencing on the PB2 gene, are indicated by the colored bars. The gray bars correspond to samples that were not included in the next-generation sequencing. Source data are provided as a Source Data file.