PROS1 and influenza: SP-A prevents influenza infection by occupying the HA binding site (38). SP-A limits RSV infection by binding the F and G protein (39). SP-A limits coronavirus infection by binding HCoV-229E virions (40). SP-A can neutralize SARS-CoV-2 through interaction with the S protein (41). SP-A mediates the phagocytosis of human papillomavirus 16 (HPV16) pseudovirions (42) and herpes simplex virus (HSV) in the host.