The growth of echovirus 1 in HEp-2 cells treated with antibody to the host cells.

Antibody prepared against HEp-2 cells inhibited the replication of echovirus I. The number of infective centres was reduced and the cells which were infected produced less virus per cell than control cells. The attachment of virus to cells was not affected. The inhibition was reduced by increasing the multiplicity of infection. Application of antibody 5 min. after virus adsorption at 4 ° reduced the inhibition and there was little inhibition when it was applied IO min. after adsorption. The antiserum had no inhibitory effect when infection was initiated by virus RNA; the antiserum may act by preventing uncoating of the virus.