Sharma J M
Avian Dis. 1985 Oct-Dec;29(4):1155-69.
Studies with specific-pathogen-free chickens revealed that chicks hatching from eggs inoculated at the 18th day of embryonation with infectious bursal disease (IBD) vaccine viruses of low virulence (isolates TC-IBDV and BVM-IBDV) developed antibody against IBD virus (IBDV) and resisted challenge with virulent IBDV at 3 weeks of age or older. Embryo vaccination did not adversely affect hatchability of chicks or survival of hatched chicks. Chicks embryonally vaccinated with TC-IBDV had transient histologic lesions in the bursa of Fabricius at hatch. Similar but milder lesions were also noted in chickens that received TC-IBDV at hatch. The level of protection following embryo vaccination with TC-IBDV and BVM-IBDV was similar to that following vaccination with the same vaccines at hatch. Vaccine viruses of moderate virulence (isolates BV-IBDV and 2512-IBDV) were not suitable as vaccines in embryos lacking maternal antibody to IBDV, because the vaccinated chicks developed acute IBD after hatch. Isolate 2512-IBDV was not pathogenic for embryos bearing maternal antibody to IBDV. Maternal antibody against IBDV interfered with efficacy of embryo vaccination with BVM-IBDV but not with 2512-IBDV. Embryo vaccination with a mixture of vaccines against IBD and Marek's disease resulted in protection of hatched chicks against challenge with virulent IBDV and Marek's disease virus.
对无特定病原体鸡的研究表明，用低毒力传染性法氏囊病（IBD）疫苗病毒（分离株TC - IBDV和BVM - IBDV）在胚胎发育第18天接种的种蛋孵化出的雏鸡，在3周龄及以上时产生了针对IBD病毒（IBDV）的抗体，并能抵抗强毒IBDV的攻击。胚胎接种对雏鸡的孵化率或孵化后雏鸡的存活率没有不利影响。用TC - IBDV进行胚胎接种的雏鸡在孵化时法氏囊有短暂的组织学病变。在孵化时接受TC - IBDV的鸡中也观察到类似但较轻的病变。用TC - IBDV和BVM - IBDV进行胚胎接种后的保护水平与在孵化时用相同疫苗接种后的保护水平相似。中等毒力的疫苗病毒（分离株BV - IBDV和2512 - IBDV）不适用于缺乏IBDV母源抗体的胚胎，因为接种疫苗的雏鸡在孵化后会发生急性IBD。分离株2512 - IBDV对携带IBDV母源抗体的胚胎无致病性。针对IBDV的母源抗体干扰了用BVM - IBDV进行胚胎接种的效果，但不干扰用2512 - IBDV进行胚胎接种的效果。用针对IBD和马立克氏病的混合疫苗进行胚胎接种，可使孵化出的雏鸡抵抗强毒IBDV和马立克氏病病毒的攻击。
