PROTECTION OF GOATS AGAINST PESTE DES PETITS RUMINANTS WITH A VACCINIA VIRUS DOUBLE RECOMBINANT EXPRESSING THE F-GENE AND H-GENE OF RINDERPEST VIRUS

Peste des petits ruminants (PPR) is a viral disease of goats and sheep characterized by necrotizing and erosive stomatitis, enteritis and pneumonia. The causative agent, PPRV, is a member of the family Paramyxoviridae and the genus Morbillivirus. Other members of the genus include rinderpest (RPV), measles, canine distemper and phocid distemper viruses. PPR has a very high rate of morbidity and mortality, and effective control of this disease is of economic importance in Africa, Asia and the Middle East. Currently, there is no safe and effective vaccine available against the disease. The tissue culture rinderpest vaccine (TCRV) protects small ruminants against severe disease; there are, however, clinical problems associated with vaccination. This laboratory has recently developed several effective vaccinia virus recombinant vaccines for rinderpest. These vaccines are easy to administer, inexpensive to produce and heat-stable. Goats were vaccinated with a vaccinia virus double recombinant expressing the haemagglutinin and fusion genes of RPV. Although vaccinated animals developed antibodies (neutralizing and ELISA) to RPV, and not to PPRV, they were completely protected against challenge inoculation with virulent PPRV. This would indicate that protection is most probably due to cell-mediated immunity. Use of the rinderpest double recombinant vaccinia virus in areas of the world where PPRV is endemic would aid in the control and eradication of PPR.