Effect of the anti-RSV mAb (motavizumab) on pulmonary function. Airway obstruction was assessed by whole body plethysmograph by measuring basal Penh daily during the first two weeks after infection and weekly up to day 28. Values represent median; errors bars, 25th–75th percentile. Each group consisted of 8 mice. Results of two separate experiments are shown. * p < 0.001 by Kruskal-Wallis ANOVA on ranks for comparison between RSV-infected untreated, sham inoculated controls and RSV-infected treated with motavizumab at -24 h.