Efficacy study of genotype matched Newcastle disease virus vaccine between eyedrop and drinking water vaccination in specific-pathogen-free chickens

Tan, Iee Hong (2022) Efficacy study of genotype matched Newcastle disease virus vaccine between eyedrop and drinking water vaccination in specific-pathogen-free chickens. [Project Paper] (Submitted)

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Abstract

Newcastle disease (ND) is a highly contagious disease that causes up to 100% mortality in birds. A genotype-matched vaccine was found to be effective in controlling ND in commercial chickens. This study aims to determine the efficacy of genotype-matched NDV vaccine (mIBS025) following eye drop (ED) and drinking water (DW) vaccination in specific-pathogen-free (SPF) chickens. The study was conducted on 135 SPF day-old chicks that were divided into 9 groups. Group 1 was the non-vaccinated group, groups 2 to 5 were vaccinated once via ED at 14 days old, while groups 6 to 9 were vaccinated via DW twice at 1 and 14 days old. The doses for both vaccinated routes range from 104.5 embryonic infectious dose (EID)50, 105EID50, 105.5EID50, and 106EID50. At 35 days old, all the birds were challenged via an intranasal route with 106EID50 with velogenic genotype VII.2 NDV strain UPM008/2021. No clinical symptoms were observed in all the groups 1-day post challenge (pc). In the unvaccinated group, mild clinical signs were observed on day 2 pc, and by day 3 and 4 pc, the birds were showing moderate clinical signs such as swollen eyes, ruffles and depression that became severe on day 5 pc onwards. The mortality rate of the unvaccinated group started on day 5 pc and by day 9 pc, 13 out of 15 birds had died (87 %). The mortality rate reached 100% at day 12 pc. In the vaccinated group, no mortality was recorded, and only one chicken in the ED group showed mild clinical signs of swollen eyes. Post-mortem examination of the dead chickens showed generalised congestion, and tracheal and lung haemorrhage. In conclusion, single ED vaccination and two doses of DW vaccination with genotype-matched ND vaccine, mIBS025 can confer complete protection against challenges with genotype VII ND in SPF chickens.

Item Type:	Project Paper
Faculty:	Faculty of Veterinary Medicine
Depositing User:	Ms. Nordeena Abdul Aziz
Date Deposited:	29 Feb 2024 07:06
Last Modified:	29 Feb 2024 07:06
URI:	http://psaspb.upm.edu.my/id/eprint/1648

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