Described is a replication-competent virus capable of replication and having lytic capacity in target cells. The virus comprises in the genome thereof, at least one DNA sequence coding for a silencing factor functional in reducing expression of a target gene in the target cells, operably linked to one or more expression control sequences, functional in the target cells. The use thereof in the preparation of a medicament and the use thereof in a method for lysing target cells expressing a virus inhibitory factor are also described.
