[Creation of an avirulent immunogenic mutant of the transmissible gastroenteritis virus and its use as a vaccine].

The serial cultivation of a virulent strain of the virus of transmissive gastroenteritis in the presence of the antimetabolite 5-bromurazil has led after a definite number of passages to the production of a virus mutant of new biologic properties. It was established that the mutant is resistant to the antimetabolite, and it retains its infectious titer. It is avirulent to newborn and growing pigs, and confers solid immunity in the vaccinated animals which do not become virus carriers. It is stable with regard to its newly-obtained biologic properties.