Newcastle disease virus vectored infectious laryngotracheitis vaccines protect commercial broiler chickens in the presence of maternally derived antibodies

Abstract

Newcastle disease virus (NDV) recombinants expressing the infectious laryngotracheitis virus (ILTV) glycoproteins B and D have previously been demonstrated to confer complete clinical protection against virulent ILTV and NDV challenges in naive chickens. We extended this study to assess whether maternally derived antibody (MDA) against NDV and ILTV would interfere with protection in vaccinated broiler chickens. Chickens with a mean NDV MDA hemagglutination inhibition (HI) titer of 6.4 (log) and detectable ILTV neutralization (VN) antibodies at hatch were vaccinated with rLS/ILTV-gB or rLS/ILTV-gD at 1 or 10day of age (DOA) or on both days. Groups of birds vaccinated with the commercial ILT vaccines (FP-LT and CEO) or sham inoculated were also included in this study. All vaccinated birds were challenged with virulent ILTV strain at 21 DOA. By that time, NDV HI titers declined to 2.6 (log) in unvaccinated birds, whereas the HI titers in NDV vectored vaccine groups increased to 3.5-6.3 (log). At standard dosages, both vaccine candidates conferred significant clinical protection; however, the protection elicited by the rLS/ILTV-gD was superior to that of rLS/ILTV-gB. Recombinant rLS/ILTV-gD reduced ILTV shedding from tracheal and ocular tissues by approximately 3 log TCID. Notably, there was no improvement in protection after booster vaccination at 10 DOA. Overall results indicate that the presence of maternal antibodies to NDV and ILTV did not significantly interfere with the ability of the NDV LaSota strain-vectored ILTV gB and gD vaccine candidates to elicit protective immunity against infectious laryngotracheitis.

Recombinant Newcastle Disease Virus (NDV) Expressing Sigma C Protein of Avian Reovirus (ARV) Protects against Both ARV and NDV in Chickens

“…Following vaccination, the recombinant NDV generated an effective humoral immune response against ND and ARV infection. Protection against NDV is primarily by the humoral immune response, as is evidenced by several earlier vaccine studies [17,40,41,42]. Moreover, the anti-σC antibody response generated with the recombinant virus was comparable with the ARV inactivated vaccine.…”

Infectious laryngotracheitis: Etiology, epidemiology, pathobiology, and advances in diagnosis and control – a comprehensive review

“…The isolate was suggested to be a recombinant of vaccine strain and another recombinant virus (Sabir et al 2020). To overcome the limitations and biosafety concerns of conventional vaccines, recombinant vaccines such as FPV vector vaccine expressing glycoprotein B and UL32 genes of ILTV(McGeoch et al 2006), two HVT vector vaccines, one containing ILTV glycoproteins I and D, and another containing ILTV glycoprotein B (Esaki et al 2013), LaSota strain of Newcastle diseases virus (NDV) that expresses ILTV glycoproteins (Kanabagatte Basavarajappa et al 2014;Zhao et al 2014), modified very virulent Marek's disease virus (vvMDV) that express ILTV glycoproteins (Gimeno et al 2015) and recombinant vaccines expressing different ILTV glycoproteins including gB, gC, gD, gG, gI, gJ, TK, UL0, UL32, and UL47 (Vagnozzi et al 2012;Yu et al 2017) were introduced and evaluated. NDV vector expressing gD of ILTV protected birds against both ILT and ND.…”

Newcastle Disease Virus Vectored Chicken Infectious Anaemia Vaccine Induces Robust Immune Response in Chickens

“…Immunisation of birds was carried out via intranasal, oral routes as this virus has lost its virulence due to the change in FPCS region, as reported earlier [ 8 ]. A detectable immune response was seen in birds after primary vaccination which significantly increased after the first and second boosters [ 24 , 32 , 33 , 34 ]. Moreover, antibodies against CIAV also showed a similar trend as described [ 13 ].…”