Filoviruses, including Ebola, have the potential to be transmitted via 
virus-laden droplets deposited onto mucus membranes. Protecting against such 
emerging pathogens will require understanding how they may transmit at mucosal 
surfaces and developing strategies to reinforce the airway mucus barrier. Here, 
we prepared Ebola pseudovirus (with Zaire strain glycoproteins) and used 
high-resolution multiple-particle tracking to track the motions of hundreds of 
individual pseudoviruses in fresh and undiluted human airway mucus isolated from 
extubated endotracheal tubes. We found that Ebola pseudovirus readily penetrates 
human airway mucus. Addition of ZMapp, a cocktail of Ebola-binding 
immunoglobulin G antibodies, effectively reduced mobility of Ebola pseudovirus 
in the same mucus secretions. Topical delivery of ZMapp to the mouse airways 
also facilitated rapid elimination of Ebola pseudovirus. Our work demonstrates 
that antibodies can immobilize virions in airway mucus and reduce access to the 
airway epithelium, highlighting topical delivery of pathogen-specific antibodies 
to the lungs as a potential prophylactic or therapeutic approach against 
emerging viruses or biowarfare agents.