Efficacy and transmissibility of Newcastle disease I-2 vaccine strain against a field isolate of virulent ND virus (JF820294.1) in village chicken

Abstract

This study was conducted to assess efficacy of heat-stable I-2 vaccine against Newcastle diseases in vaccinated and vaccinated in contact birds group following challenge against virulent Newcastle disease (ND) virus in village chicken. Also, to assess whether birds that have been exposed to vaccine virus-shedding, birds were protected against mortality and clinical signs after infection with a virulent strain of the ND virus (NDV). One hundred fifty one-day-old native chickens were divided into seven groups (4 experimental groups of 30 birds/group and 3 control groups (unvaccinated unchallenged, challenged, and just vaccinated). Birds in experimental groups were vaccinated either via drinking water or as food carrier with thermostable I-2 vaccine and then challenged with virulent isolate of NDV (JF820294.1), and eight birds were added as in-contact birds to vaccinated groups. Following challenge, seven extra birds were added to each group as in contact with vaccinated and challenged birds. Survival rate, clinical signs, necropsy finding, and mean antibody titer were evaluated in different experimental and control groups. Birds vaccinated via drinking water showed 100% survival rate. However, birds vaccinated with food carrier vaccine showed less than 50% survival rate. Based on the results obtained from this study, it can be recommended that I-2 vaccination via drinking water can effectively prevent ND in village chicken, since I-2 strain has been able to transmit to non-vaccinated-sensitive birds more effectively than velogenic NDV.

Current situation and future direction of Newcastle disease vaccines

“…These strains present low virulence and good safety in chickens of all ages [ 33 , 34 ]. Moreover, V4 and I-2 are typical thermostable vaccines with the unique advantages of being used in remote country areas with limited cold chain facilities, which can be administered through drinking water and food intake [ 35 – 37 ].…”

Eliciting preferences for attributes of Newcastle disease vaccination programmes for village poultry in Ethiopia

“…This may suggest farmers would prefer NCD vaccine that could be administered via water with a likelihood for more uptake, by farmers if the vaccine could be given in water. Route of vaccine administration affects vaccine efficacy; trial studies in village poultry show that I-2 vaccination administered via water is twice as efficacious as compared to vaccine administered via food carrier ( Habibi et al, 2015 ). Therefore, future NCD vaccination programme could possibly achieve better efficacy and wider acceptance by using preferred route of vaccine administration, via water.…”

“…This may suggest the need to consider acceptable routes of vaccine administration to ensure wider adoption of NCD vaccine technology by village poultry keepers. Village poultry NCD vaccine efficacy studies show that vaccines administered via water are efficacious compared with other roots ( Thekisoe et al, 2004 ; Habibi et al, 2015 ). Therefore, future NCD vaccine programmes will have the potential to achieve a twin goal of achieving high efficacy and better acceptability as farmers highly prefer vaccines administered via water.…”

Thermostable Vaccines in Veterinary Medicine: State of the Art and Opportunities to Be Seized

“…Most of the studies included are on vaccines against avian diseases, and, in particular, against NDV [42][43][44][45][46][52][53][54][55][56][57][58]67,[69][70][71]73,75,76,78,79,[82][83][84]. Developing a thermostable vaccine for Newcastle disease (ND) was considered a priority for non-governmental organisations (NGOs) and studies were funded to evaluate the effectiveness and economic viabilities of the vaccination in developing countries.…”