Lau S C, Cassel W A
Infect Immun. 1972 Mar;5(3):359-62. doi: 10.1128/iai.5.3.359-362.1972.
An inhibitor acting against vaccinia virus hemagglutinin, and producing a hemagglutinin-negative virus, was separated from tumorous ascitic plasma. The finding that the partially purified inhibitor was biologically active strengthens the evidence for a specific role of the inhibitor in altering the virus.