VACCINE FOR PROPHYLAXIS OF CHICKEN BURSA INFECTIOUS SICKNESS, LYOPHILIZED VIRAL COMPOSITION, METHOD OF CHICKEN PROTECTION FROM THIS DISEASE AND A METHOD OF LIVE VACCINE PREPARING Russian patent published in 1999 - IPC

FIELD: agriculture, veterinary science, virology. SUBSTANCE: invention relates to new vaccines against bursa infectious sickness in chickens produced on the basis of new attenuated viral strains deposited in ECACC. Three new strains, - MB, MB-2 and MB-1 are intermediate-pathogenic but they can not induce disease. Vaccine is produced by the following procedure: eggs with developing embryos are inoculated, embryos and membranes are collected and live vaccine is prepared from homogenate with addition of stabilizing agent. Vaccine dose is used at the range 10²-10⁴ ДИ Я₅₀.. Live vaccine must contain one of viral strain or a mixture of two indicated strains, or a mixture of all indicated viral strains. Chickens vaccinated with live vaccine produce precipitating antibodies and type of specific neutralizing antibodies that show immunity to the following infection with Israel virulent bursa infectious sickness and to infection with European strain. Vaccine provides an universal immunity against bursa infectious sickness. EFFECT: improved method of preparing, enhanced effectiveness of vaccine proposed. 17 cl, 1 dwg, 7 tbl, 8 ex