“With most viruses, the inhibitory effect of (Humic Acid) is directed specifically against an early stage of virus replication, namely virus attachment to cells (Klocking and Sprosig, 1975; Schols et al., 1991; Neyts et al., 1992).”
“…it appears likely that the poly-anionic Humic Acids occupy positively charged domains of the viral envelope glycoproteins, which are necessary for virus attachment to the cell surface (Neyts et al., 1992).”