[Immunogenic properties of 3 local lentogenic strains of the Newcastle disease virus used in the spray method of vaccination].

Three local lentogenic strains of the Newcastle disease virus, GT, D and R, were made use of to produce live liquid vaccines. These proved harmless and immunogenic when applied through the spray-method to broiler chicks, aged 5 days, at three successive revaccinations (on the 25th, 60th and 140th day of age) carried out by the same method. The strain D vaccine induced serum antihemagglutinins that had higher titers than those induced by vaccines of the other local strains and the standard strains Hitchner-B1 and La Sota.