S20-190 Engineered Nanobodies to Protect against Viral and Microbial Contamination in Closed and Semi-enclosed Spaces SARS-CoV2 is known to gain entry into epithelial cells through the association of its viral spike protein with the ACE2 receptor, which is widely expressed on epithelial cell types. Charles Chan Liming Zhao Yunxiao Zhang Yuting Wang Andrew Lee Michael Longaker Holly Steininger