Antigenic shift of visna virus in persistently infected sheep

Science  22 Jul 1977:
Vol. 197, Issue 4301, pp. 376-378
DOI: 10.1126/science.195339


Visna viruses isolated from persistently infected sheep were antigenically distinct from the plaque-purified virus used for inoculation. The selection of antigenic variants under antibody pressure, thought to occur in vivo, was reproduced in sheep cell cultures inoculated with plaque-purified visna virus and maintained in antibody. Antigenic shift may be a mechanism for persistence of virus in slow or recurrent viral infections.