Pseudotype particles of vesicular stomatitis virus with surface antigens of bovine leukaemia virus--VSV (BLV) -- as a sensitive probe for detecting antibodies in the sera of spontaneously infected cattle.

Phenotypically mixed particles containing the genome of vesicular stomatitis virus (VSV) and envelope antigen corresponding to bovine leukaemia virus (BLV) -- the VSV (BLV) pseudotypes -- can be employed as a rapid, specific and sensitive probe for detecting BLV-neutralizing antibodies in bovine sera.