A vaccinia virus double recombinant expressing the F and H genes of rinderpest virus protects cattle against rinderpest and causes no pock lesions.

Rinderpest is a highly contagious viral disease of ruminants with greater than 95% morbidity and mortality. We have constructed an infectious vaccinia virus recombinant that expresses both the fusion (F) gene and the hemagglutinin (H) gene of rinderpest virus. The Wyeth strain of vaccinia virus was used for the construction of the recombinant. Cattle vaccinated with the recombinant virus were 100% protected from challenge inoculation with greater than 1000 times the lethal dose of rinderpest virus. No transmission of recombinant vaccinia virus from vaccinated animals to contact animals was observed. The lyophilized form of vaccinia virus is thermostable and allows circumvention of the logistical problems associated with the distribution and administration of vaccines in the arid and hot regions of Asia and Africa. The insertional inactivation of both the thymidine kinase and the hemagglutinin genes of vaccinia virus led to increased attenuation of the virus; this was manifested by the lack of detectable pock lesions in vaccinated animals. This approach may have wide application in the development of safe and efficacious recombinant vaccines for humans and animals. This becomes quite relevant with the concern of the use of vaccinia virus in a population with high incidence of the human immunodeficiency virus.