de Wit J J, Jorna I, Finger A, Loeb V, Dijkman R, Ashash U, Ifrah M, Raviv Z
Royal GD, Deventer, the Netherlands.
Veterinary Faculty, Utrecht University, Utrecht, the Netherlands.
Avian Pathol. 2021 Dec;50(6):531-539. doi: 10.1080/03079457.2021.1986618. Epub 2021 Nov 19.
Infectious bursal disease (IBD) is an economically important disease of young chickens caused by the Avibirnavirus infectious bursal disease virus (IBDV). Besides biosecurity, vaccination is the most important measure for IBDV control. Sufficient levels of maternally derived antibodies (MDA) protect against early challenge and also interfere with the take of live conventional vaccines. Recently, the field surveys conducted in four countries, published by Ashash, U., Noach, C., Perelman, B., Costello, C., Sansalone, P., Brazil, T. & Raviv, Z. [(2019). and day of hatch application of a live infectious bursal disease virus vaccine to commercial broilers. , 63, 713-720] using the MB-1 vaccine strain by application or sub-cutaneous route at the day of hatch seem to conflict with the rule that very early application of a conventional live vaccine in birds with significant levels of MDA has very little chance of a successful immune response. An vaccination-challenge controlled experiment with MB-1 vaccine was performed using commercial broilers with high levels of MDA against IBDV and a vvIBDV challenge at 22 or 36 days of age. Clinical signs, bursa-bodyweight ratios, histology, serology, RT-PCR, Sanger- and deep sequencing were used to study the efficacy and safety of the -applied MB1 vaccine in comparison to an established immuno-complex vaccine. The study findings confirmed that the application of the live MB-1 vaccine in commercial broilers was successful and induced full protection against a vvIBDV challenge at 22 and 36 days of age, demonstrated by the bursa lesion score and qPCR and IBDV genotyping. Comparable to the field studies, a delayed viral replication of 2-3 weeks, following the administration of the MB1 vaccine, was observed.
传染性法氏囊病（IBD）是由禽双RNA病毒传染性法氏囊病病毒（IBDV）引起的对幼鸡具有重要经济影响的疾病。除生物安全措施外，疫苗接种是控制IBDV的最重要措施。足够水平的母源抗体（MDA）可预防早期感染，同时也会干扰常规活疫苗的接种效果。最近，阿沙什、U.、诺亚克、C.、佩雷尔曼、B.、科斯特洛、C.、桑萨洛内、P.、巴西、T.和拉维夫、Z. [（2019年）。以及在孵化日对商品肉鸡应用活传染性法氏囊病病毒疫苗的皮下途径] 使用MB - 1疫苗株在孵化日进行应用，这似乎与在具有高水平MDA的禽类中非常早期应用常规活疫苗成功免疫反应机会很小的规则相冲突。使用对IBDV具有高水平MDA的商品肉鸡进行了一项MB - 1疫苗接种 - 攻毒对照实验，并在22或36日龄时用vvIBDV进行攻毒。通过临床症状、法氏囊与体重比值、组织学、血清学、RT - PCR、桑格测序和深度测序来研究与已建立的免疫复合物疫苗相比，孵化日应用的MB1疫苗的有效性和安全性。研究结果证实，在商品肉鸡中孵化日应用活MB - 1疫苗是成功的，并在22和36日龄时诱导了对vvIBDV攻毒的完全保护，这通过法氏囊病变评分、qPCR和IBDV基因分型得以证明。与现场研究类似，在应用MB1疫苗后观察到病毒复制延迟2 - 3周。
