Immune Responses in the Harderian Gland After Newcastle Disease Vaccination in Chickens with Maternal Antibodies.

Immune responses in the Harderian gland (HG) were characterized after Newcastle disease virus (NDV) LaSota ocular vaccination in antibody-naïve specific-pathogen-free (SPF) chickens and in chickens of commercial origin with NDV maternally derived antibodies (MDA). Ocular LaSota vaccination of 13-day-old white leghorn SPF chickens elicited serum antibody levels that consistently increased 15 days postvaccination, while the specific IgA response in lacrimal fluids was already detectable 10 days after vaccination. Eleven days postvaccination, the relative abundance of B cells, as well as T-helper cells (CD4+) and cytotoxic T cells (CD8+), in HGs was significantly increased, achieving maximum frequencies 16 days postvaccination. In a second experiment, chickens with MDA originating from NDV-vaccinated commercial white leghorn layer breeders, as well as white leghorn SPF chickens, were vaccinated with NDV LaSota. The LaSota virus successfully replicated in periocular tissues and in the trachea both in commercial and control SPF chickens after vaccination at 2 or 15 days of age (DOA). Vaccination at 2 DOA did not induce a serum NDV antibody response in chickens of commercial origin. In contrast, seroconversion was elicited in commercial chickens upon vaccination at 15 DOA, likely associated with waning of MDA. Unlike systemic IgG responses, vaccination at 2 or 15 DOA elicited strong specific IgA responses in lacrimal fluids in commercial chickens. The IgA response was highest 9 days after vaccination and showed a tendency to decline 15 days postvaccination. Commercial chickens vaccinated at 2 DOA showed increased B cells in HG 10 and 16 days postvaccination. The expansion of B cells in the HG in these chickens is consistent with increased IgA levels detected in lacrimal fluids. In contrast, control SPF chickens showed a more limited B-cell expansion in HG and lower IgA levels. Vaccination at 15 DOA also triggered a greater increase of B cells in HGs in commercial chickens than in control SPF chickens. The B-cell response was accompanied by T-helper (CD4+) cell expansion, occurring both in commercial and control SPF chickens. These cells expanded to a lesser extent when vaccination was performed at 2 DOA compared with vaccination at 15 DOA. CD8+ showed significant expansion irrespective of vaccination day and without differences detected between control SPF chickens and chickens with MDA. We conclude that NDV LaSota elicits vigorous humoral and cell immune responses in the HG. Furthermore, unlike the interference shown by MDA on vaccine-induced serum antibody responses, MDA do not interfere with the mucosal immune response of the HG.

Respuestas inmunes en la glándula de Harder después de la vacunación contra la enfermedad de Newcastle en pollos con anticuerpos maternos. Se caracterizaron las respuestas inmunes en la glándula de Harder (HG) después de la vacunación ocular con la cepa LaSota contra el virus de la enfermedad de Newcastle (NDV) en pollos libres de patógenos espec'ificos (SPF) sin anticuerpos y en pollos de origen comercial con anticuerpos maternos (MDA) contra el virus de Newcastle. La vacunación ocular con cepa LaSota en aves White Leghorn libres de patógenos espec'ificos de 13 d'ias de edad indujo niveles de anticuerpos séricos que aumentaron consistentemente 15 d'ias después de la vacunación, mientras que la respuesta espec'ifica de IgA en los fluidos lagrimales ya era detectable a los 10 d'ias después de la vacunación. Once d'ias después de la vacunación, la abundancia relativa de células B, as'i como de células T colaboradoras (CD4+) y células T citotóxicas (CD8+), en la glándula de Harder aumentó significativamente, alcanzando frecuencias máximas 16 d'ias después de la vacunación. En un segundo experimento, se vacunaron con la cepa LaSota de Newcastle pollos con anticuerpos maternales procedentes de reproductoras comerciales de aves de postura White Leghorn vacunadas con el NDV, as'i como gallinas White Leghorn libres de patógenos espec'ificos. El virus LaSota se replicó con éxito en los tejidos perioculares y en la tráquea tanto de pollos comerciales como en las aves controles libres de patógenos espec'ificos después de la vacunación a los 2 o 15 d'ias de edad. La vacunación a los dos d'ias de edad no indujo una respuesta de anticuerpos séricos contra el virus de Newcastle en pollos de origen comercial. Por el contrario, se indujo seroconversión en pollos comerciales tras la vacunación a los 15 d'ias de edad, probablemente asociada con una disminución de los anticuerpos maternos. A diferencia de las respuestas sistémicas de IgG, la vacunación a los dos o 15 d'ias de edad provocó fuertes respuestas de IgA espec'ificas en los fluidos lagrimales en pollos comerciales. La respuesta de IgA fue máxima nueve d'ias después de la vacunación y mostró una tendencia a disminuir 15 d'ias después de la vacunación. Los pollos comerciales vacunados con dos d'ias de edad mostraron un aumento de células B en la glándula de Harder 10 y 16 d'ias después de la vacunación. La expansión de las células B en la glándula de Harder en estos pollos es consistente con el aumento de los niveles de IgA detectados en los fluidos lagrimales. Por el contrario, los pollos controles libres de patógenos espec'ificos mostraron una expansión de células B más limitada en la glándula de Harder y niveles más bajos de IgA. La vacunación con 15 d'ias de edad también provocó un aumento importante de células B en la glándula de Harder en pollos comerciales en comparación con los pollos controles libres de patógenos espec'ificos. La respuesta de las células B estuvo acompañada por la expansión de las células T colaboradoras (CD4+), que ocurrió tanto en pollos comerciales como en los controles libres de patógenos espec'ificos. Estas células se expandieron en menor medida cuando la vacunación se realizó a los dos d'ias de edad en comparación con la vacunación a los 15 d'ias de edad. Las células CD8+ mostraron una expansión significativa independientemente del d'ia de vacunación y sin diferencias detectadas entre los pollos control libres de patógenos espec'ificos y los pollos con anticuerpos maternales. Se concluye que la cepa de Newcastle LaSota provoca robustas respuestas inmunes humorales y celulares en la glándula de Harder. Además, a diferencia de la interferencia mostrada por los anticuerpos maternos en las respuestas de anticuerpos séricos inducidas por la vacuna, los anticuerpos maternos no interfieren con la respuesta inmune de la mucosa de la glándula de Harder.

Assessment of Different Newcastle Disease Virus Antigens and Inactivators of Binary Ethylene Amine and Formalin for the Hemagglutination Inhibition Assay.

Newcastle disease is a severe viral threat to the global poultry industry due to its high prevalence and rapid transmission. Evaluating vaccination timing and effectiveness is crucial, often accomplished through the hemagglutination inhibition (HI) assay. This test relies on the virus's agglutination ability in certain animals, utilizing various inactivated antigens. Our study aimed to assess multiple Newcastle viral antigens ( LaSota, clone, thermo-resistant strain, B1, and V4 ) inactivated by binary ethylene amine (BEA) and formalin, seeking the best antigen and inactivator for the HI assay. We prepared the different ND antigens include; LaSota, Clone, thermo resistant, B1, V4 and the mixture of the antigens then inactivated them using BEA and formalin. The hemagglutination (HA) assay determined mean titers, comparing BEA and formalin inactivation. These antigens were also subjected to the HI test using 112 serum samples from different commercial poultry flocks to assess their performance. BEA-inactivated antigens exhibited significantly higher mean titers in the HA assay than formalin-inactivated antigens. In the evaluation of different antigens in the HI test, the mean titer of antigen B1 followed by clone and LaSota displayed a higher mean titer than others. In conclusion, this study recommends using Hitchner pathotype antigens, specifically the B1 vaccine, for Newcastle disease HI testing. BEA is the preferred inactivator, preserving antigen structure particularly the structure of hemagglutinin antigen while minimizing risks. These findings can enhance serological testing accuracy, contributing to more effective disease control and prevention in the poultry industry.

Assessment of PPMV-1 Genotype VI Virulence in Pigeons and Chickens and Protective Effectiveness of Paramyxovirus Vaccines in Pigeons.

Pigeon paramyxovirus serotype 1 (PPMV-1), an antigenic and host variant of avian paramyxovirus Newcastle disease virus (NDV), primarily originating from racing pigeons, has become a global panzootic. Egypt uses both inactivated PPMV-1 and conventional NDV vaccines to protect pigeons from disease and mortality. However, the impact of prevalent strains and the effectiveness of available vaccines in pigeons in Egypt are unclear. This study investigates the virulence of PPMV-1 (Pigeon/Egypt/Sharkia-19/2015/KX580988) and evaluates available paramyxovirus vaccines in protecting pigeons against a PPMV-1 challenge. Ten-day-old specific-pathogen-free (SPF) embryonated chicken eggs infected with this strain exhibited a mean death time (MDT) of 86.4 ± 5.88 h. The intracerebral pathogenicity index (ICPI) in day-old chickens was 0.8, while pigeons experienced an ICPI of 0.96 and an intravenous pathogenicity index (IVPI) of 2.11. These findings classify the strain as virulent and velogenic. Experimental infection of pigeons with this PPMV-1 strain at 106 EID50/0.1 mL resulted in a 62.5% mortality rate, displaying nervous and enteric distress. The virus caused extensive lesions in visceral organs, with strong immunohistochemistry signals in all examined organs, indicating the systemic spread of the virus concurrent to its neurotropic and viscerotropic tropism. Furthermore, vaccination using an inactivated PPMV-1 and live NDV LaSota vaccine regimen protected 100% of pigeons against mortality, while with a single NDV LaSota vaccine, it was 62.5%. The PPMV alone or combined with NDV LaSota induced protective levels of haemagglutination inhibition (HI) antibody titres and reduced virus shedding from buccal and cloacal cavities. Based on generalised linear gamma model analysis, both PPMV-1 and NDV LaSota are antigenically comparable by HI. These findings suggest that using both inactivated PPMV-1 (G-VI) and live attenuated NDV (LaSota) vaccines is an effective prophylactic regimen for preventing and controlling PPMV-1 and NDV in pigeons, thereby reducing the risk of interspecies transmission.

Effects of spray-dried plasma on performance, carcass parameters, tibia quality and Newcastle disease vaccine efficacy in broiler chicken fed corn-soy diets with two varying levels of digestible amino acids and AMEn density.

This study aimed to determine the effects of spray dried plasma (SDP) on growth performance, carcass traits, tibia quality, and hemagglutination inhibition titers in broilers fed two nutritional strategies with high or low nutrient density. In the study, 816 one-day-old Ross 308 male broiler chickens were divided into a 2 × 2 factorial arrangements consisting of four treatment groups with 12 replicates (17 birds/replicate) based on diets with high nutrient density (HND) or low nutrient density (LND) from d 0 to 42 and receiving either control or 1% SDP diets during d 0 to 10. The results showed that feed intake (FI) and body weight gain (BWG) were increased (P < 0.05) and feed conversion ratio (FCR) was significantly reduced (P = 0.003) for broilers fed HND diets from d 0 to 42. The inclusion of SDP increased the BWG (P < 0.001), FI (P < 0.001), and FCR (P < 0.05) during d 0 to 10 of broiler life but not effect of SDP was observed for the whole 0-42 d period. Carcass yield increased with HND (P < 0.001) and dietary SDP (P = 0.002). However, HND feeding significantly decreased liver (P < 0.001), bursa of Fabricius (P = 0.002), abdominal fat (P < 0.001), proventriculus (P < 0.001) and gizzard weight (P < 0.001), but increased heart weight (P = 0.013), although spleen weight remained unaffected (P > 0.05) on d 42. Tibial bone morphometric and mechanical properties improved (P < 0.05) with SDP supplementation, and bone ash, Ca, and P remained unaffected (P > 0.05) on d 14. With the exception at d 28 (P = 0.037), the antibody titer to ND virus was similar among all treatment groups (P > 0.05) at d 0, 14, and 42. In conclusion, HND diets improve performance of broilers during the whole period and SDP supplementation during starter phase improve performance at this period, but also increased carcass yield, and tibial quality. Therefore, inclusion of SDP in the starter diet could be a beneficial nutritional strategy to improve the health and production of broilers provided feeding strategies using various nutrient densities.

A Newcastle disease live virus vaccine is safe and efficacious at various storage conditions.

Pure, potent and efficacious vaccines could help in the control of Newcastle disease (ND). The present study was designed to evaluate the thermo-stability of a live-attenuated ND virus vaccine containing the Mukteswar strain and to genetically characterize the seed virus. Moreover, the presence of extraneous agents (Fowl adenovirus, Mycoplasma, Salmonella Pullorum, and Salmonella Gallinarum) was assessed using polymerase chain reactions (PCR) optimized for detection in a panel. The vaccine was evaluated for its potency and efficacy after storage at 4°C, 25°C and 37°C for 36, 48, 96 and 144 hours. A total of 100 commercial broiler chickens were randomly divided into six groups and immunized with the vaccine stored at specified temperatures for the given times. Blood samples were collected on days 0, 7, 14, 21 and 28 post-vaccination, sera were separated and antibody titers were assessed using hemagglutination inhibition (HI) assay. The data were analyzed by two-way analysis of variance (ANOVA) and multivariate analysis of variance (MANOVA). Reverse-transcription  PCR targeting the F gene of Newcastle disease virus (NDV) and subsequent sequence analysis confirmed the presence of NDV in the vaccine seed (deposited to GenBank Acc. Nos. MK310260 and MK310261). Phylogenetic analysis revealed a close resemblance of the vaccine virus with other Avian Avulaviruses (NDV class II Genotype III viruses and more specifically with NDV Mukteswar vaccine strains), yet it was distinct from NDV class II Pakistani field isolates, which grouped into genotype XIII.2.1. The PCR testing confirmed that the vaccine was free from extraneous agents. The present study's findings propose an alternative rapid PCR-based method to evaluate the purity of NDV live vaccines. Together these data suggest that the tested vaccine is pure, potent and efficacious, yet continuous maintenance of the cold chain for vaccine storage is recommended to maintain its potency and efficacy.

Impact of dietary arginine supplementation on immune responses and growth performance in Newcastle disease virus-infected broiler chicks.

BACKGROUND: Newcastle disease (ND) poses significant challenges within the poultry industry, leading to increased mortality rates, compromised growth, weakened immunity and elevated levels of inflammation. OBJECTIVE: This study explores the potential of dietary arginine supplementation to ameliorate these adverse effects of ND, leveraging arginine's well-documented benefits in enhancing growth and immune responses. METHODS: A total of 480 one-day-old male broiler chicks were meticulously categorised into eight groups, encompassing both infected and noninfected cohorts. These chicks received diets with arginine levels at 85%, 100%, 125% and 150% of recommended standards. The study entailed a comprehensive examination of clinical manifestations, growth performance metrics, haemagglutination inhibition (HI) test results, and serum concentrations of proinflammatory cytokines, adrenocorticotropic hormone (ACTH), and cortisol (CORT). RESULTS: The infection significantly curtailed feed consumption (p = 0.0001) and weight gain (p = 0.0001) while concurrently depressing HI titres. Additionally, infected chicks experienced an exacerbated feed conversion ratio (p = 0.0001), escalated mortality rates (p = 0.0001), and elevated serum concentrations of proinflammatory cytokines (p = 0.0001), ACTH (p = 0.0001), and CORT (p = 0.0001). Remarkably, dietary arginine supplementation effectively mitigated the adverse impacts of ND infection on growth, immune responses and proinflammatory cytokine levels. In the context of ND infection, mortality rates and inflammation surge, while growth and immunity are significantly compromised. CONCLUSIONS: The strategic inclusion of arginine in the diet emerges as a potent strategy to counteract the deleterious effects of ND. Supplementation with arginine at levels exceeding the conventional dietary recommendations is recommended to alleviate the detrimental consequences of ND effectively.

Effectiveness of a community-centered Newcastle disease vaccine delivery model under paid and free vaccination frameworks in southeastern Kenya.

In the absence of effective drugs, vaccines constitute the cornerstone for the prevention of Newcastle disease (ND). Different strategies have been implemented to increase vaccination, but uptake remains low, underscoring the need for novel vaccine delivery methods. We designed and assessed the effectiveness of a community-centered ND vaccine delivery model in southeastern Kenya. Under the model, we sensitized smallholder chicken farmers (SCFs) through structured training on chicken husbandry, biosecurity, ND, and its vaccination, among other aspects. We subsequently engaged trained community vaccinators (CVs) to deliver vaccines and/or provide vaccination services to SCFs at a cost on one hand and, at no cost on the other, in selected sites to address challenges of inadequate service providers, vaccine unavailability, and inaccessibility. We tested this model under paid and free vaccination frameworks over one year and assessed the model's effect on vaccine uptake, ND-related deaths, and vaccine accessibility, among other aspects. Overall, we vaccinated more chickens at free sites compared to paid sites. However, we vaccinated a significantly higher mean number of chickens per household at paid (49.4±38.5) compared to free (28.4±25.9) sites (t = 8.4, p<0.0001). We recorded a significant increase in the proportion of SCFs who vaccinated their chickens from 31.3% to 68.4% (χ2(1, N = 399) = 58.3, p<0.0001) in paid and from 19.9% to 74.9% (χ2(1, N = 403) = 115.7, p<0.0001) in free sites pre- and post-intervention, respectively. The mean number of ND-related deaths reported per household decreased from 18.1±31.6 pre-intervention to 7.5±22.3 post-intervention (t = 5.4, p = 0.000), with higher reductions recorded in paid sites (20.9±37.7 to 4.5±11.2) compared to free sites (15.0±22.6 to 10.7±29.7) pre- and post-intervention, respectively. Farmers with access to vaccines increased significantly from 61.1% to 85.4% (χ2(1, N = 399) = 31.7, p<0.0001) in paid and 43.6% to 74.9% (χ2(1, N = 403) = 38.4, p = 0.0001) in free sites pre- and post-intervention, respectively. We established that type of intervention framework, gender of household head, if the household head attended training on chicken production in the last 12 months, access to information on ND vaccination, and the number of chickens lost to the previous ND outbreak were significant predictors of ND vaccine uptake. Our findings indicate the model has a broader reach and benefits for SCFs. However, policies should be enacted to regulate the integration of CVs into the formal animal health sector.

Evaluation of the immune responses of biological adjuvant bivalent vaccine with three different insertion modes for ND and IBD.

Infectious bursal disease (IBD) is a widespread problem in the poultry industry, and vaccination is the primary preventive method. However, moderately virulent vaccines may damage the bursa, necessitating the development of a safe and effective vaccine. The Newcastle disease virus (NDV) has been explored as a vector for vaccine development. In this study, reverse genetic technology was used to obtain three recombinant viruses, namely, rClone30-VP2L (P/M)-chGM-CSF (NP), rClone30-chGM-CSF (P/M)-VP2L (NP), and rClone30-VP2L-chGM-CSF (P/M). Animal experiments showed that the three biological adjuvant bivalent vaccines effectively increased anti-NDV and anti-infectious bursal disease virus (IBDV) titres, enhancing both humoral and cellular immune responses in chickens without leading to any harm. Amongst the three biological adjuvant bivalent vaccines, the rClone30-chGM-CSF (P/M)-VP2L (NP) group had higher levels of anti-NDV antibodies at 14 days after the first immunization and stimulated a greater humoral immune response in 7-10 days. While, the rClone30-VP2L (P/M)-chGM-CSF (NP) group was the most effective in producing a higher level of IBDV antibody response. In conclusion, these three vaccines can induce immune responses more rapidly and effectively, streamline production processes, be cost-effective, and provide a new avenue for the development of Newcastle disease (ND) and IBD bivalent vaccines.

Authorizing of Immunogenicity of Concentrated and Purified Newcastle Disease Virus V4 Strain using Downstream Processing.

Newcastle disease virus (NVD) from the Paramyxoviridae family is a single-stranded negative-sense RNA virus. This infection can affect both domestic poultry and almost all other bird species. It has been considered a very severe difficulty for the poultry industry all over the world. Even though it remains a potential threat to poultry industries, this virus is a powerful oncolytic virus as well. In this study, a process was accomplished to achieve concentrated and highly purified NDV V4 strain particles. Downstream processing of Newcastle virus strain V4 was characterized by amplifying virus in embryonated chicken eggs. Through a sequence of steps, harvesting allantoic fluid, clarification by centrifuge, concentration by ultrafiltration, and size exclusion separation, the reduced volume and pure virus particles were considered for the amount of ovalbumin, hemagglutinin activity, transmission electron microscopy (TEM), electrophoresis, and additionally immunogenicity of prepared antigens. The results presented a high recovery of HA activity in concentrated and purified virus with the removal of ovalbumin and the typical morphology based on TEM. Sepharose CL-4B was determined as the best media among all used resins to purify the virus. Prepared formulations as vaccines demonstrated positive hemagglutinin inhibition for 6 months and stability for 2 years. Strong evidence from organized studies supports the effectiveness of this method in concentrating and purifying intact NDV, which could be valuable in vaccine research, antiserum preparation, or even as an alternative oncotic agent to traditional methods. Despite further studies being conducted, this method can be utilized particularly on a semi-industrial scale to produce various vaccine components.

Spray vaccination with a Newcastle disease virus (NDV)-vectored infectious laryngotracheitis (ILT) vaccine protects commercial chickens from ILT in the presence of maternally-derived antibodies.

Infectious laryngotracheitis (ILT) poses a significant threat to the poultry industry, and vaccines play an important role in protection. However, due to the increasing scale of poultry production, there is an urgent need to develop vaccines that are suitable for convenient immunization methods such as spraying. Previous studies have shown that Newcastle disease virus (NDV)-ILT vaccines administered via intranasal and intraocular routes to commercial chickens carrying maternally-derived antibodies (MDAs) are still protective against ILT. In this study, a recombinant NDV (rNDV) was generated to express infectious laryngotracheitis virus (ILTV) glycoprotein B (gB), named rLS-gB, based on a full-length cDNA clone of the LaSota strain. The protective effect of different doses of rLS-gB administered by spray vaccination to commercial chickens at 1 d of age (doa) was evaluated. The chickens were exposed to 160-µm aerosol particles for 10 min for spray vaccination, and no adverse reactions were observed after vaccination. Despite the presence of anti-NDV MDAs and anti-ILTV MDAs in chickens, the ILTV- and NDV-specific antibody titres were significantly greater in the vaccinated groups than in the unvaccinated group. After challenge with a virulent ILTV strain, no clinical signs were observed in the 107 EID50/ml group compared to the other groups. Furthermore, vaccination with 107 EID50/ml rLS-gB significantly reduced the ILTV viral load and ameliorated gross and microscopic lesions in the trachea of chickens. Overall, these results suggested that rLS-gB is a safe and efficient candidate spray vaccine for ILT and is especially suitable for scaled chicken farms.

Thermostable vacuum foam dried Newcastle disease vaccine: Process optimization and pilot-scale study.

Vacuum foam drying (VFD) has been shown to improve the thermostability and long-term shelf life of Newcastle Disease Virus (NDV). This study optimized the VFD process to improve the shelf life of NDV at laboratory-scale and then tested the optimized conditions at pilot-scale. The optimal NDV to T5 formulation ratio was determined to be 1:1 or 3:2. Using the 1:1 virus to formulation ratio, the optimal filling volumes were determined to be 13-17% of the vial capacity. The optimized VFD process conditions were determined to be at a shelf temperature of 25℃ with a minimum overall drying time of 44 h. The vaccine samples prepared using these optimized conditions at laboratory-scale exhibited virus titer losses of ≤ 1.0 log10 with residual moisture content (RMC) below 3%. Furthermore, these samples were transported for 97 days around China at ambient temperature without significant titer loss, thus demonstrating the thermostability of the NDV-VFD vaccine. Pilot-scale testing of the NDV-VFD vaccine at optimized conditions showed promising results for up-scaling the process as the RMC was below 3%. However, the virus titer loss was slightly above 1.0 log10 (approximately 1.1 log10). Therefore, the NDV-VFD process requires further optimization at pilot scale to obtain a titer loss of ≤ 1.0 log10. Results from this study provide important guidance for possible industrialization of NDV-VFD vaccine in the future. KEY POINTS: • The process optimization and scale-up test of thermostable NDV vaccine prepared through VFD is reported for the first time in this study. • The live attenuated NDV-VFD vaccine maintained thermostability for 97 days during long distance transportation in summer without cold chain conditions. • The optimized NDV-VFD vaccine preparations evaluated at pilot-scale maintained acceptable levels of infectivity after preservation at 37℃ for 90 days, which demonstrated the feasibility of the vaccine for industrialization.

The Application of Newcastle Disease Virus (NDV): Vaccine Vectors and Tumor Therapy.

Newcastle disease virus (NDV) is an avian pathogen with an unsegmented negative-strand RNA genome that belongs to the Paramyxoviridae family. While primarily pathogenic in birds, NDV presents no threat to human health, rendering it a safe candidate for various biomedical applications. Extensive research has highlighted the potential of NDV as a vector for vaccine development and gene therapy, owing to its transcriptional modularity, low recombination rate, and lack of a DNA phase during replication. Furthermore, NDV exhibits oncolytic capabilities, efficiently eliciting antitumor immune responses, thereby positioning it as a promising therapeutic agent for cancer treatment. This article comprehensively reviews the biological characteristics of NDV, elucidates the molecular mechanisms underlying its oncolytic properties, and discusses its applications in the fields of vaccine vector development and tumor therapy.

Efficacy of live and inactivated recombinant Newcastle disease virus vaccines expressing clade 2.3.4.4b H5 hemagglutinin against H5N1 highly pathogenic avian influenza in SPF chickens, Broilers, and domestic ducks.

A Newcastle disease virus (NDV)-vectored vaccine expressing clade 2.3.4.4b H5 Hemagglutinin was developed and assessed for efficacy against H5N1 highly pathogenic avian influenza (HPAI) in specific pathogen-free (SPF) chickens, broilers, and domestic ducks. In SPF chickens, the live recombinant NDV-vectored vaccine, rK148/22-H5, achieved complete survival against HPAI and NDV challenges and significantly reduced viral shedding. Notably, the live rK148/22-H5 vaccine conferred good clinical protection in broilers despite the presence of maternally derived antibodies. Good clinical protection was observed in domestic ducks, with decreased viral shedding. It demonstrated complete survival and reduced cloacal viral shedding when used as an inactivated vaccine from SPF chickens. The rK148/22-H5 vaccine is potentially a viable and supportive option for biosecurity measure, effectively protecting in chickens against the deadly clade 2.3.4.4b H5 HPAI and NDV infections. Furthermore, it aligns with the strategy of Differentiating Infected from Vaccinated Animals (DIVA).

Effects of in ovo vaccination time on broiler performance parameters under field conditions.

Hatchery performance is often evaluated based on descriptors such as hatchability, 7-d mortality, and cost. In addition to these descriptors, it is useful to include in this analysis aspects of chick quality through post-hatch performance. Realizing the bird's complete genetic potential necessitates meeting various criteria, with effective support for the chick's immune system being among the pivotal factors. To be effective, in ovo vaccination systems must deliver the vaccines to specific sites in the egg, a circumstance that directly depends on when the injection is made. We examined production data to evaluate the impact of in ovo vaccination time on performance parameters of male Ross308AP chicks. A comprehensive survey was conducted examining records from 3,722 broiler flocks produced and raised by the same company under standard nutrition and management conditions. The selected data specifically pertained to flocks that underwent slaughter between 41 and 45 d. In our analysis, 4 different linear models were built, one for each response variable: mean weight (MW), body weight gain (BWG), corrected feeding conversion rate (cFCR), and total mortality (TM). The linear models used in the analyses included as main predictor the timing of in ovo vaccination (440, 444, 448, 452, 456, 458, and 460 h of incubation), and as additional predictors: age of the breeding flock (26-35, 36-55 and 56-66 wks old), slaughter age, identity of the hatchery, and the season at which the data was collected. Our results showed that the timing of in ovo vaccination significantly affected BWG and cFCR, with procedures performed at 460 h of incubation showing the best outcomes. Breeding flock age affected all response variables, with older breeding flocks delivering increased MW, BWG and TM, and middle-aged flocks increased cFCR. Increasing slaughter age reduced BWG while MW, cFCR and TM were all increased. These data emphasize the benefits of performing in ovo vaccination as close as possible to 460 h of incubation to extract the best BWG and cFCR from Ross308AP male broiler.

Newcastle disease virus: the past and current situation in Indonesia.

The Newcastle disease virus (NDV) outbreak was first reported in Java Island, Indonesia, in 1926, which was then reported further in Newcastle-upon-Tyne, England. Nevertheless, the NDV is still endemic in Indonesia, with outbreaks occurring in free-range and commercial chicken farms. The dynamic evolution of the NDV has led to the further development of vaccines and diagnostic tools for more effective control of this virus. This paper discusses the history of the NDV occurrence, vaccines, the development of diagnostic tools, and the epidemiological condition of the NDV in Indonesia. Indonesia, which has the largest poultry population in the world after China, has challenges in preventing and controlling this virus that causes economic losses to the farmers and has an impact on the welfare of the poultry farming community in Indonesia.

Cytokine expression, protection and shedding reduction induced by the combination of lipopolysaccharide with Montanoid ISA71 in oil-based Newcastle disease vaccine.

Oil-based inactivated ND vaccines are a commonly used control strategy for this endemic disease in Egypt. One of the major limitations of these inactivated vaccines is the time taken to develop a protective response in vaccinated birds. In the present study, we aimed to formulate an inactivated oil-based ND vaccine incorporated with lipopolysaccharide (LPS) that stimulates the early onset innate response to inactivated vaccines via proinflammatory cytokine production. Five groups of 21-day old SPF chicks were reared in isolators and were treated as follows: G1: Montanoid ISA71 adjuvanted NDV vaccinated group, G2: LPS and Montanoid ISA71 adjuvanted NDV vaccinated group, G3: LPS and Montanoid ISA71 with phosphate buffer saline received group and two non-vaccinated control groups. NDV specific antibodies and cell mediated immune responses were evaluated by hemagglutination inhibition and lymphocyte proliferation tests, respectively. Transcriptional responses of the TLR4, IFN-γ and IL-2 genes were analyzed in peripheral blood mononuclear cells (PBMCs) following vaccination by qRT-PCR. Protection % was determined after challenge with a lethal strain of NDV 106 EID50/0.5 ml. Viral shedding was assessed on oropharyngeal swabs by qRT-PCR and infectivity titration on SPF-ECE. The results revealed that the incorporation of LPS with ISA71 in the oil-based ND vaccine induced a synergistic response confirmed by significant humoral and lymphoproliferative responses with a significant increase in Th1 cytokine transcripts. The simultaneous use of both adjuvants in G2 demonstrated complete protection and a significant reduction in viral shedding compared to the ISA71-adjuvated ND vaccine in G1, which conferred 90 % protection.

Protective effects of a novel chimeric virus-like particle vaccine against virulent NDV and IBDV challenge.

Newcastle disease (ND) and infectious bursal disease (IBD) pose significant threats to the chicken industry, causing substantial economic losses. Currently, immunization through vaccination is the most effective strategy to prevent ND and IBD but currently used traditional vaccines, including inactivated or attenuated vaccines, face challenges in achieving a balance between immunogenicity and safety. To develop a green and efficient novel vaccine for ND and IBD, we developed a bivalent chimeric virus-like particle vaccine (ND-IBD cVLPs) displaying the ND virus (NDV) HN protein and the IBD virus (IBDV) VP2 protein based on the ND VLPs carrier platform and insect baculovirus expression system. This study aimed to evaluate the immunogenicity and protective efficacy of ND-IBD cVLPs in specific pathogen-free chickens. Chickens were immunized with 50 µg of purified ND-IBD cVLPs at 7 days old, boosted at 21 days old, and challenged at 42 days old. The results demonstrated that ND-IBD cVLPs stimulated highly effective hemagglutination inhibition antibody levels against NDV HN protein and enzyme-linked immunosorbent assay antibody levels against the IBDV VP2 protein. Furthermore, ND-IBD cVLPs provided complete protection against virulent NDV and IBDV challenges and mitigated pathological damage to the lung caused by NDV infection and the bursa of Fabricius caused by IBDV infection. These findings suggest that ND-IBD cVLPs hold promise as a safe and efficient novel vaccine candidate for the effective prevention of ND and IBD, extending the development of a foreign protein delivery platform of ND VLPs.

The effects of the LaSota strain of oncolytic Newcastle disease virus vaccine on cervical intraepithelial neoplasia Patients-Clinical cohort study.

BACKGROUND: Cervical cancer is one of the most common malignancies in women, and its treatment has many side effects. Therefore, in this research, the effects of the LaSota strain of oncolytic Newcastle disease virus vaccine on cervical intraepithelial neoplasia (CIN) patients were investigated. METHODS: 15 patients who met the inclusion criteria and diagnosed as CIN II and CIN III were included in the study. The vaccine was injected inside the cervix (neoplasia site) at increasing doses during 21 days, and they were evaluated for adverse events. NDV antibody titer was measured in 90 days and the levels of ki-67 and p16 proteins were studied by immunohistochemistry. Also, the levels of some important inflammatory cytokines in the serum of CIN patients were measured and finally the patients were evaluated according to the final outcomes and the reduction of tumor lesions. RESULTS: Only in the first dose of vaccine some patients showed flu-like symptoms. The accumulation of NDV antibodies started on the 7th day of the study and increased until the 90th day. Administration of LaSota vaccine had no significant effect on the expressions of Ki-67 and p16 proteins. Nevertheless, a decrease in the serum levels of Il-1ß was observed in patients after the administration of the vaccine, but the serum levels of both Il-2 and INF-γ upregulated significantly. Also, vaccine administration had no significant effect in reducing CIN grades and lesions. CONCLUSIONS: In general, we concluded that LaSota strain of NDV vaccine has no therapeutic effectiveness in CIN patients.

In vivo challenge studies on vaccinated chickens indicate a virus genotype mismatched vaccine still offers significant protection against NDV.

Although commercial vaccines against Newcastle Disease have been available for decades, outbreaks still occur in the face of vaccination Further vaccination may accelerate viral evolution resulting in a further reduction in vaccine efficacy. A key question is whether genotype-matched vaccines can confer better protection against contemporary type 1 Avian Paramyxoviruses. To assess this, an in vivo vaccine-challenge study was undertaken to assess protection afforded by 'genotype-matched' and commercial vaccine formulations. Groups of chickens were vaccinated twice (prime-boost) with an inactivated preparation of either La Sota Clone 30, AV632-chicken-Cyprus-13 (genotype VII.2), or mock vaccine, and later challenged with virulent AV632-chicken-Cyprus-13. Post vaccinal serological responses differed, although both vaccination/challenge groups showed similar levels of clinical protection compared to the unvaccinated group, where 100 % mortality was observed. Shedding was significantly reduced in the vaccinated groups compared to the unvaccinated group. Virus dissemination in the tissues of vaccinated birds was comparable, but onset of infection was delayed. Two mutations were observed in the HN gene of the heterologous vaccine group; H199N and I192M, the latter thought to be associated with increased fusogenic potential. These data demonstrate that existing vaccine formulations confer similar levels of clinical protection to contemporary strains and that the antigenic heterogeneity of circulating strains does not impact upon shedding profiles in immunised birds. In conclusion, the ability of virulent APMV-1 to cause disease in vaccinated flocks is unlikely to be the result of antigenic mismatch alone, and other factors likely contribute to vaccination failure and breakthrough.

Development and evaluation of a bivalent vaccine based on recombinant newcastle disease virus expressing infectious bursal disease virus VP2L-CH3-CH4 in SPF chickens.

Newcastle disease (ND) and infectious bursal disease (IBD) are two viral infectious diseases that are extremely damaging to the poultry industry and are widespread throughout the world. It is necessary to develop a safe and effective vaccine against IBD and ND because vaccination is an effective preventive measure. It has been discovered that recombinant proteins expressed by an expression system in which a fragment of mammalian Immunoglobulin G (IgG) Fragment crystallizable (Fc) is linked to a segment of a gene have antibody-like properties that increase the exogenous protein's serum half-life. Heavy chain constant region 3 and heavy chain constant region 4 (CH3-CH4) of Avian Immunoglobulin Y (IgY) is structurally very similar to mammalian Ig G Fc. In this study, a bivalent vaccine rClone30-VP2L-CH3-CH4-GMCSF was developed by using NDV rClone30-chGM-CSF vector to produce VP2L-CH3-CH4 fusion protein. The vaccine has been given to 14-day-old specific pathogen free (SPF) free chickens to test whether it has the potential to prevent IBD and ND. Anti-IBDV and anti-NDV antibody levels in serum were evaluated using ELISA and HI, respectively, and the contents of CD4+ T, CD8+ T, and B cells in leukocytes were determined via flow cytometry. The contents and mRNA transcription levels of four inflammatory factors, IL-1ß, IL-4, IFN-γ and chGM-CSF, were detected by ELISA and real-time PCR respectively. The results showed that after vaccination with the rClone30-VP2L-CH3-CH4-GMCSF vaccine, the levels of anti NDV and anti IBDV antibodies in chickens were significantly higher than those of the rClone30 vaccine and commercial vaccines. Meanwhile, the contents and transcription levels of inflammatory factors in chickens inoculated with rClone30-VP2L-CH3-CH4-GMCSF were significantly increased, and the proliferation response of B cells, CD4+ and CD8+ T cells was also stronger. However, the rClone30-VP2L-CH3-CH4-GMCSF vaccine had no significant advantage over the rClone30-VP2L-GMCSF vaccine in any of the above-mentioned features. In summary, rClone30-VP2L-CH3-CH4-GMCSF can stimulate the body to produce a stronger immune response, showing its potential to be considered as vaccine against IBD and ND, but the addition of CH3-CH4 did not improve the vaccine's immune effect as expected. The research lays the foundation for developing vaccines for other infectious viral diseases and avoids a unrealistic vaccine optimization method.