The efficacy of binary ethylenimine-inactivated vaccines of Gianyar-1/AK/2014 virulent strain in protecting chickens against Tabanan-1/ARP/2017 virulent Newcastle disease virus isolates.

Anak Agung Ayu Mirah Adi,I Nyoman Mantik Astawa,I Gusti Agung Arta Putra

doi:10.14202/vetworld.2019.758-764

Anak Agung Ayu Mirah Adi, I Nyoman Mantik Astawa + Show 1 more

Open Access

https://doi.org/10.14202/vetworld.2019.758-764

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Journal: Veterinary world	Publication Date: Jun 1, 2019
Citations: 3	License type: CC BY 4.0

Affiliation: Udayana University

Abstract

Aim: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.Materials and Methods: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 log2 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.Results: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 log2 HI units, 4.9±0.99 log2 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 log2 HI units, 6.9±0.32 log2 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.Conclusion: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.

Highlights

Newcastle disease (ND) is a devastating poultry disease caused by a virulent strain of Avian paramyxovirus type 1 (APMV-1)
The challenge test with virulent Newcastle disease virus (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 phosphate-buffered saline (PBS) (Group III) died with clinical signs of ND
This finding shows that the binary ethylenimine (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

Summary

Introduction

Newcastle disease (ND) is a devastating poultry disease caused by a virulent strain of Avian paramyxovirus type 1 (APMV-1). The APMV-1, which is known as ND virus (NDV), has a very wide genetic diversity but can genetically be classified into two distinct classes: Class I and II. Viruses of Class I are mostly found in wild waterfowls and generally consist of avirulent strains. The viruses of Class II are found in poultry and consist of both avirulent and virulent strains. There are 18 genotypes (genotype I-XVIII) in Class II [1].

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