[Study of the immunity in swine vaccinated with type C anti-foot-and-mouth disease vaccine].

Experiments were carried out to adapt a cell culture strain of the foot-and-mouth disease virus, type C, to the organism of susceptible pigs. It was established that 4 to 5 passages are needed to adapt the virus, all treated animals showing the symptoms of the disease from the 24 hour following infection which assumed a generalized course. In determining the index of protection (P) of a given F.M.D. vaccine through challenging immunized pigs its value proves to be 4.5. It is stressed that this is a suitable and economic method to evaluate the immunogenic properties of F.M.D. vaccines for pigs.