- 期刊
荷蘭泌乳牛於不同免疫適期施打不活化牛流行熱疫苗對抗體力價之影響
The evaluation of neutralizing antibody titers elicited by different vaccination program of inactivated bovine ephemeral fever virus vaccine on Holstein cattle in Taiwan
摘要
牛流行熱（Bovine Ephemeral Fever, BEF）是牛隻重要的病毒性疾病，我國在防治BEF策略上廣泛使用不活化疫苗，以提升整體牛群於年度易感期之疫苗保護力。本試驗以不同疫苗株之不活化疫苗進行荷蘭牛1年2次（A組）或1年3次（B組）之免疫施打次數，並採集血清監測牛隻牛流行熱病毒（BEF virus, BEFV）中和抗體力價、分析施打前後中和抗體力價上升倍數、無反應牛及弱反應牛之比例，進行免疫適期的評估，以達維護牛群健康及減少疫病發生率。結果顯示，牛隻施打不同BEFV疫苗株後對各階段之抗體力價無顯著影響。分析牛隻施打疫苗前後中和抗體上升倍數，顯示A組於第一劑疫苗施打後3個月、6個月及第二劑疫苗施打後6個月，其抗體較施打前分別上升2.48、2.68及1.37倍；而B組於第一劑疫苗後4個月、第二劑疫苗施打後4個月及第三劑疫苗施打後4個月，抗體較施打前分別上升4.22、3.96及1.87倍；B組於不同階段之抗體上升倍數皆大於A組（P＜0.05）。本試驗顯示每年實施3次BEF不活化疫苗較2次者可得到更高的中和抗體力價保護效果，預期可以提昇泌乳牛的使用年限及生產性能並減少經濟損失，並可作為規劃BEF疫苗免疫計畫之參考依據。落實仔牛於4至6月齡時完成2劑BEF疫苗（間隔4週）之基礎免疫，其後至少每6個月（北半球於3月及8月）補強施打1劑疫苗，若需確保年度牛隻具有高抗體保護力價則建議應每4個月補強施打1劑，即每年施打3次不活化疫苗為佳。
並列摘要
Bovine ephemeral fever (BEF) is an important viral disease of cattle. The protection of BEF in Taiwan mainly relies on inactivated vaccine to upgrade the vaccination protection of all cattle in times of the seasoning outbreak of BEF. To elevate the overall BEF protection of cattle, two treatment cattle groups were vaccinated with different BEF virus vaccine strains and different doses. A group (two times vaccinated per year) and B group (three times vaccinated per year). BEF virus neutralizing antibodies (NA) following vaccination with inactivated BEF vaccine were tested, and calculating the elevated NA before and after vaccinated of each group. The proportions of non-responder and weak-responder cattle were also identified. The results showed that the overall cattle herd BEFNA titers are not significantly different between A and B treatment groups at each time periods (P ＞ 0.05). Also, herd vaccinated with different BEF virus vaccine strains showed no significant differences in BEFNA titers (P ＞ 0.05). The results indicated that the administration of cattle with different BEFV vaccine does not have significant impact on the antibody titers at different stage. However, significant differences were found between the elevated BEFNA titers of A and B treatment groups at each time periods (P ＞ 0.05). The elevated BEFNA titers of A treatment group were 2.48, 2.68, and 1.37 times than the titer before vaccination, 3 and 6 months post 1^(st) vaccination, and 6months post 2^(nd) vaccination, respectively. While the elevated BEFNA titers of B treatment group were 4.22, 3.96, and 1.87 times than the titer before vaccination, 4 months post 1^(st) vaccination, 4 months post 2^(nd) vaccination and 4 months post 3^(rd) vaccination, respectively. This study indicates that the vaccination program of 3 inactivated vaccine doses per year will yield higher protection effect from the neutralizing antibody titers than just 2 vaccine doses. Vaccines are expected to prolong the shelf life of milking cows and their production performance in addition to reducing economic loses, which can be taken into consideration for designing the BEF vaccination program. It may be recommended that initial vaccination will be performed twice at the age of 4 to 6 month (4 weeks apart) and then repeated every 6-month period (March and August in the north hemisphere). To achieve better protection of BEF, cattle should be vaccinated with inactivated vaccine every 4-month period, namely to reach 3 doses per year for optimal performance.