MedImmune's Motavizumab Reduced RSV Hospitalizations by 83 Percent Among High-Risk Native American, Full-Term Infants in Placebo-Controlled Phase 3 study – MedImmune, Inc. today announced that in a Phase 3 study, motavizumab was shown to reduce hospitalizations due to respiratory syncytial virus (RSV) by 83 percent as compared to placebo (8.3 percent in placebo arm vs. 1.4 percent in motavizumab;