Research on the schizont cell culture vaccine against Theileria annulata infection in Xinjiang, China.
Theileria annulata infection (TAI) is one of the most serious diseases of cattle in Xinjiang Autonomous Region of Uigur Minority Nationality. It has been recorded in 14 prefectures, except the Tulufan Prefecture, but the enzootic areas are mainly distributed around the Zhunger Basin and Talim Basin. According to the records collected in the ten years before vaccination with the schizont cell culture vaccine was carried out, the average incidence rate of TAI in enzootic areas was 7.22% and the mortality rate was 24%. The milk production of cattle suffering from TAI was sharply decreased, and there were usually abortions in pregnant cows. The incidence rate and mortality rate were greater in high grade cattle, so TAI was a constraint to improving cattle breeds. To control this disease effectively in Xinjiang, researchers at the Xinjiang Academy of Animal Science began to study the schizont cell culture vaccine in 1972. In 1977 an immortalised cell line was achieved from a primary cell culture starting with white blood cells from cattle suffering from acute TAI caused by an artificial tick bite. The cell culture medium mainly consisted of calf serum, lactalbumin-hydrolysate, Eagles' medium DMEM and three antibiotics. As a vaccine, the above cells were mixed with preserving medium containing gelatin. This paper describes the experiments on the immunological properties of the vaccine carried out in subsequent years. Up to 1996, vaccine doses for 1,186,150 cattle have been produced and sold. This vaccine has had a critical effect on the control of TAI in Xinjiang. Owing to the sharp decrease in the incidence rate and mortality rate of TAI after cattle were vaccinated, the annual economic benefit of the vaccine is at least 1,620,000 yuan.
Guo
G
G
Institute of Veterinary Research, Xinjiang Academy of Animal Science, Urumqi, People's Republic of China.
Shang
J
J
Yu
M
M
Zhao
J
J
Ma
S
S
Ali
N
N
Tan
L
L
Maliyam
D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000453:epidemiology / Q000517:prevention & control*; D002681:China / Q000453:epidemiology; D003470:Culture Media; D015994:Incidence; D007962:Leukocytes / Q000469:parasitology; D016052:Protozoan Vaccines / Q000191:economics / Q000276:immunology; D016796:Theileria annulata / Q000276:immunology*; D013801:Theileriasis / Q000453:epidemiology / Q000517:prevention & control*; D014611:Vaccination / Q000662:veterinary
D003470:Culture Media; D016052:Protozoan Vaccines