THE PRESENT INVENTION DISCLOSES A REPLICATION-DEFICIENT PSEUDOINFECTIVE VIRUS BELONGING TO THE FLAVIVIRIDAE FAMILY THAT LACK THE CAPSID GENE, WHERE THE REPLICATION- DEFICIENT PSEUDOINFECTIVE VIRUS PROPAGATES ONLY IN CELLS EXPRESSING THE CAPSID OR CAPSID, prM AND ENVELOPE PROTEIN OF THE FLAVIVIRUS. THE PRESENT INVENTION ALSO DISCLOSES THE METHOD OF PRODUCING SUCH VIRUSES ON A LARGE SCALE AND THE USE OF THESE PSEUDOINFECTIVE VIRUSES AS VACCINES FOR PREVENTING DISEASES CAUSED BY INFECTIONS OF HUMANS OR ANIMALS BY THE VIRUSES BELONGING TO THIS FAMILY.