601827 Discloses a recombinant MVA virus expressing a polypeptide comprising human prostatic acid phosphatase (PAP) antigen, wherein the virus is MVA-BN as deposited under ECACC accession number V00083008. Also discloses the use of the virus with the PAP antigen in a medicament for inducing B cell and T cell immune responses against PAP, where the medicament is formulated for administering one or more boosting doses of the MVA/PAP virus.