Adi Anak Agung Ayu Mirah, Astawa I Nyoman Mantik, Putra I Gusti Agung Arta
Laboratory of Veterinary Pathology, Faculty of Veterinary Medicine, Udayana University, Kampus Sudirman, Jalan PB Sudirman, Denpasar, Bali, Indonesia.
Laboratory of Veterinary Virology, Faculty of Veterinary Medicine Udayana University, Kampus Sudirman, Jalan PB Sudirman, Denpasar, Bali, Indonesia.
Vet World. 2019 Jun;12(6):758-764. doi: 10.14202/vetworld.2019.758-764. Epub 2019 Jun 8.
This study aimed to prepare binary ethylenimine (BEI)-inactivated virulent Newcastle disease virus (NDV) vaccine and to examine their ability to induce a protective antibody response in commercial chickens.
A virulent NDV field isolate Gianyar-1/AK/2014 was propagated in chicken-embryonated eggs and was then inactivated with BEI at a concentration of 4 mM. Three groups of chickens with low-level (2 log hemagglutination inhibition [HI] units) maternally derived antibodies against NDV were then immunized with the BEI-inactivated vaccine. A commercial live vaccine (LaSota strain) was used as positive control, and phosphate-buffered saline (PBS) was used as negative control. A challenge experiment with a virulent NDV of Tabanan-1/ARP/2017 was performed at 3 weeks post-vaccination.
At 2 weeks post-immunization, the mean titers of antibodies against NDV in serum samples of chickens immunized with 0.2 mL of BEI-inactivated NDV (Group I), with live commercial NDV vaccine (Group II) and with PBS (Group III) were 3±0.94 log HI units, 4.9±0.99 log HI unit, and 0.0±0.0 HI units, respectively. At week 3 post-immunization, the mean titers of the antibodies for the three groups were 5±1.09 log HI units, 6.9±0.32 log HI units, and 0.00 HI units, respectively. The antibody titer induced by inactivated NDV Gianyar-1/AK/2014 isolates examined at 2 and 3 weeks post-vaccination was still at a significantly (p<0.01) lower level as compared to those induced by commercial life vaccine. However, the challenge test with virulent NDV of Tabanan 1/ARP/2017 isolates showed that all immunized chickens (Group I and II) survived without exhibiting any clinical sign post-challenge with the protection rates of 100%, whereas all chickens injected with PBS (Group III) died with clinical signs of ND.
This finding shows that the BEI-inactivated vaccines prepared using virulent NDV of Gianyar-1/AK/2014 strain was able to induce protective antibody response in chickens but still at a lower level than those induce by commercial live NDV vaccine.
本研究旨在制备二元乙撑亚胺（BEI）灭活的强毒新城疫病毒（NDV）疫苗，并检测其在商品鸡中诱导保护性抗体反应的能力。
一株强毒NDV田间分离株Gianyar-1/AK/2014在鸡胚中增殖，然后用浓度为4 mM的BEI灭活。然后用BEI灭活疫苗免疫三组具有低水平（2个对数血凝抑制[HI]单位）抗NDV母源抗体的鸡。使用一种商业活疫苗（LaSota株）作为阳性对照，磷酸盐缓冲盐水（PBS）作为阴性对照。在接种疫苗后3周，用Tabanan-1/ARP/2017强毒NDV进行攻毒试验。
免疫后2周，用0.2 mL BEI灭活NDV免疫的鸡（I组）、用商业活NDV疫苗免疫的鸡（II组）和用PBS免疫的鸡（III组）血清样本中抗NDV抗体的平均滴度分别为3±0.94个对数HI单位、4.9±0.99个对数HI单位和0.0±0.0个HI单位。免疫后3周，三组抗体的平均滴度分别为5±1.09个对数HI单位、6.9±0.32个对数HI单位和0.00个HI单位。与商业活疫苗诱导的抗体滴度相比，在接种疫苗后2周和3周检测的由灭活的Gianyar-1/AK/2014 NDV分离株诱导的抗体滴度仍显著（p<0.01）较低。然而，用Tabanan 1/ARP/2017强毒NDV分离株进行的攻毒试验表明，所有免疫鸡（I组和II组）在攻毒后均存活，未表现出任何临床症状，保护率为100%，而所有注射PBS的鸡（III组）均死于ND临床症状。
这一发现表明，用Gianyar-1/AK/2014株强毒NDV制备的BEI灭活疫苗能够在鸡中诱导保护性抗体反应，但仍低于商业活NDV疫苗诱导的水平。
