Fig. 3: Remdesivir prophylaxis reduces features of acute lung injury.

The histological features of acute lung injury were blindly scored using the American Thoracic Society Lung Injury Scoring system creating an aggregate score for the following phenotypes: neutrophils in the alveolar and interstitial space, hyaline membranes, proteinaceous debris filling the air spaces, and alveolar septal thickening. Three randomly chosen high power (×60) fields of diseased lung were assessed per mouse. Representative images are shown for mock infected as well as those administered prophylactic vehicle or RDV and infected with either 5E + 04 or 5E + 05 pfu mouse adapted MERS-CoV. The numbers of mice scored per group: Vehicle 5E + 04 pfu MERS-CoV N = 5, Vehicle 5E + 05 pfu MERS-CoV N = 3, RDV 5E + 04 pfu MERS-CoV N = 5, RDV 5E + 05 pfu MERS-CoV N = 5. Symbols identifying example features of disease are indicated in the figure. All images were taken at the same magnification. The black bar indicates 100 µm scale. For the graph, the boxes encompass the 25th to 75th percentile, the line is at the median, while the whiskers represent the range. Statistical significance was determined by Mann–Whitney test.