Definition

A trivalent nanobody composed of three monovalent Nb017 moieties linked with glycine-serine (GS) linkers, directed against the fusion protein (F protein) of human respiratory syncytial virus (RSV), with potential activity against RSV infections. Upon administration via nebulization and inhalation, the anti-RSV nanobody ALX-0171 targets and binds to RSV F protein, neutralizing the virus, and preventing viral entry into host cells. RSV F protein is a small envelope glycoprotein required for cytopathic syncytia formation that results from cell-to-cell fusion.