口蹄疫母體移行抗體對仔牛疫苗免疫反應之影響

Effect of Maternally-Derived Antibodies on the Immune Response of Calves to Vaccination against Foot-and-Mouth Disease

李明昌(Ming-Chang Li) ； 鄭益謙(Ivan-Chen Cheng) ； 蔡清恩(Chin-En Tsai) ； 林有良(Yeou-Liang Lin) ； 陳靜美(Ching-Mei Chen) ； 鍾明華(Ming-Hwa Jong) ； 陳世平(Shih-Ping Chen)

《臺灣獸醫學雜誌》 30卷3期 (2004/09) Pp. 200-205

https://doi.org/10.7009/TVJ.200409.0200

摘要

本試驗的目的係在研究台灣仔牛母體口蹄疫移行抗體力價之半衰期以及探討移行抗體對仔牛經首次口蹄疫疫苗免疫後之抗體力價影響。於兩個牛場選取1月齡仔牛各60頭，每隔1個月採血一次（30日齡至150日齡）進行母體口蹄疫移行抗體力價測定，並進行回歸分析以估計仔牛口蹄疫移行抗體之半衰期。結果顯示，仔牛移行抗體之半衰期分別為18及21天（平均為20天），其移行抗體力價平均在70日齡後降至32倍以下。同時亦選取具母體移行抗體之仔牛45頭，分析移行抗體對仔牛經市售口蹄疫疫苗免疫後3週之抗體力價影響。結果顯示，仔牛移行抗體力價若低於256倍（Log（下標 10）值＝2.46），接受疫苗注射3週後均可激發免疫反應。綜合結果顯示仔牛首次免疫之時機應為30日齡至70日齡之間。

關鍵字

仔牛 ； 口蹄疫 ； 半衰期 ； 移行抗體 ； 中和抗體

並列摘要

The purposes of this study was to investigate the decay rate of maternally derived antibodies (MDA) titers against foot-and-mouth disease virus in calves and the effect of MDA on the response of calves to primary vaccination against foot-and-mouth disease in Taiwan. Two groups of one-month-old newborn calves (60 calves from farm A. 60 calves from farm B) were used in this study. Serum samples were periodically collected from 30 to 150 days post parturition (dpp). Sample sera were examined by the serum neutralization tests according to the method described in the OIE manual. Regression analysis was used to calculate the decay rate of MDA and the mean half-life was estimated. The results indicated that the average half-life of MDA of calves was 20 days. The mean time of MDA titers of calves dropped to 1.5 log(subscript 10) SN(subscript 50) was 70 days. In the meantime, 45 calves possessing a wide range of MDA titers at the time of vaccination were used to evaluate the effect of MDA on the primary response of calves at 21 days post-vaccination. Result revealed that calves with MDA titers lower than 2.46 log(subscript 10)SN(subscript 50) , were able to respond to FMD commercial vaccine used in this study at 3 weeks post-vaccination. In conclusion, the most suitable time for calves to get primary FMD vaccination is between 30 to 70 dpp.

並列關鍵字

Calf ； Foot-and-mouth disease ； Half-life ； Maternally derived antibodies ； Neutralizing antibodies