Influence of a papilloma vaccine on chronic bovine enzootic hematuria.

The effect of repeated injections of a formalinizod wart vaccine on development of urinary bladder tumors of cattle has been studied in the area of Bolu, Turkey, where such bovine tumors are common. The vaccine consisted of a 5 percent suspension of bovine wart tissue with formalin to make a final concentration of 0.5 percent and was injected intradormally in the caudal fold of the tail with 0.5 ml at each of two sites. The vaccine was not completely inactivated since fibropapillomas developed at the site of injection in some animals. Six hundred sixty-five calves received two vaccine injections one month apart when 6 to 12 months old, and those available were revaccinated every six months. Three hundred twenty-seven cattle served as nonvaccinated controls and received a placebo of distilled water in stead of vaccine. In one group, 8 percent of vaccinated animals (32/399) and 4.5 percent of nonvaccinated cattle (9/196) devel oped hematuria within four years after the first vaccination. In another group, 3 percent of vaccinated (8/266) and 1.5 percent of nonvaccinated (2/131) developed hematuria within less than 3 years. Seven animals with hematuria were killed to study the pathology of the bladder. The lesions resembled the early stage of naturally occurring bladder tumors which were common in the area. The pathologic changes consisted of hyperplasia, glan dular metaplasia and transitional cell papilloma. They varied with the duration of hematuria. The wart vaccine did not prevent development of tumors in the urinary bladder and may have actually enhanced the inci dence of tumors.