Newcastle Disease Vaccine Research Articles

Production of proinflammatory cytokines by expressing Newcastle disease vaccine candidates in corn

The efficacy of a plant-based edible vaccine produced in maize by expression of F and HN immunogenic proteins under a seed-specific promoter against Newcastle disease virus (NDV) genotype VII was assessed using cytokine-mediated cellular immune responses in chickens. Using real-time PCR, the mRNA expression of transgenic maize plants was compared to non-transgenic control plants on a relative basis. F and HN genes mRNA expression was found to be 20 and 60 times higher in corn seeds than in leaves, respectively. In maize seeds, 35 µg ml−1 of F protein, or 0.6 percent of total protein, and 41 µg ml−1 of HN protein, or 0.85 percent of total protein, were found using ELISA. The boost in cell-mediated immune response was evaluated in chickens fed with transgenic corn seeds in comparison with control groups. The qPCR analysis showed an increase in the expression of IL-1 (Interleukin-1), IL-2 (Interleukin-2), IL-6 (Interleukin-6), IL-8 (Interleukin-8), IL-10 (Interleukin-10), IL-15 (interleukin-15), Interferon-α, Interferon-β, Interferon-γ, and CCL3 when evaluated at 0, 7th, 14th, 21st, 28th and 35th day in chickens receiving transgenic diet as compared to group 1 receiving non-transgenic diet. The increase in cytokines production was comparable with group 3 immunized with conventional market vaccine. Furthermore, anti-NDV antibodies were also found in the serum of chickens given maize containing immunogenic proteins, but not in the serum of chickens given a regular normal diet, illustrating the antibodies’ specificity produced after feeding. The results demonstrate that transgenic maize consumed orally strongly stimulates the expression of cytokine genes related to cell-mediated immunity, just like commercial vaccines. These results further suggest that these cytokines may be important in initiating cellular immune responses in response to NDV infection.

Efficacy of different live infectious bursal disease vaccines on antibodies to infectious bursal disease virus and Newcastle disease vaccine La Sota in ISA brown chicks

Aim: In this study, the efficacy of five commercial live infectious bursal disease (IBD) vaccines on antibody (Ab) decay and response to a very virulent IBD virus (vvIBDV) and Newcastle disease (ND) vaccine La Sota in ISA Brown chicks were assessed. Methods: Seven groups of chickens (A, B, C, D, E, F, and G) comprising 50 chicks each were used for the study. Groups A, B, C, D, and E were vaccinated with Bur-706, MB-Strain, B87-Strain, Bursa-B2K, and HIPRA live IBD vaccines, respectively, at 14 and 28 days of age (doa), and challenged with a vvIBDV at 35 doa. Groups F and G served as positive and negative controls, respectively. At 42 doa, all groups were vaccinated with ND vaccine La Sota. Blood was collected at 1, 7, 14, 21, 28, 35, 42, and 49 doa, and serum was harvested. The serum was analyzed for IBD virus (IBDV) Ab titres using enzyme-linked immunosorbent assay (ELISA) and ND Ab titres using a haemagglutination inhibition (HI) test. Results: Results revealed significantly (p < 0.05) higher ELISA IBDV Ab titres in groups A to E than in F from 21 to 49 doa, with the highest in group D. At 49 doa, there was significantly (p < 0.05) higher HI Ab titre in groups A to E than in F with the highest in group D. In conclusion, the live IBDV vaccines were immunogenic following vaccination. The vaccines decreased the decay of IBDV Ab and mitigated the decreased response to ND vaccine La Sota in the chicks following the vvIBDV challenge, with more effects induced by Bursa-B2K. Conclusion: The live vaccines (Bur-706, MB-Strain, B87-Strain, Bursa-B2K, and HIPRA) were immunogenic following vaccination.

Potential Interference of Maternally Derived Antibodies (MDA) of Commercial Broiler Chicks on the Efficacy of Different Vectored –ND Vaccines

Maternally derived antibodies (MDA) are a major problem for the application of NDV-vectored vaccines in commercial chickens with high levels of MDA, which could impair its efficacy. In this study, we assessed the effectiveness of different commercial vectored ND in broilers chicks with MDA against local heterologous NDV genotype VII. For this purpose, Two hundred and forty one day old chicks were divided into eight groups (30 chicks/group) (G1, G2, G3, G4, G5, G6 and G7) vaccinated with four different recombinant ND vaccines using different vaccination scheme. In addition, Group 8 (30 chicks) kept as a control non-vaccinated group. Efficacy of this type of vaccine is evaluated routinely by vaccination-challenge test. ELISA test were used for detection antibodies from collected sera of all chickens groups. Challenge test were applied at 31th day's old age of chickens. To calculate viral Shedding, cloacal swabs were collected from all groups and examined by real time RT-PCR. Obtained results for G8 (control) was recorded high antibody titer at one day but decreased gradually till become negative at 24 day old. While vaccinated groups exhibited antibody titers at 38 days old which were 3.6, 3.7, 4, 3.7, 3.66, 3.77, and 3.3 for G1, G2, G3, G4, G5, G6 and G7, respectively. Protection% of vectored ND vaccines groups ranged from 80 to 95 % despite inactivated ND vaccine recorded 60%. It was concluded that the recombinant ND vectored vaccines more potent than inactivated one in broiler chickens with MDA. Administration of rFowl-Pox+ND vaccine at 10 day exhibited higher immune response and conferred more protection and reduction of viral shedding in comparison to vaccinated at hatchery. Using rHVT+ND vaccine in one day old chicks confer optimum immune response and protection% in presence of MDA. Prime-boost vaccination strategy can overcome the problem of MDA in broiler chickens vaccination. So, it was recommended to measure the level of MDA in offspring to determine the ideal time for vaccination

Effectiveness of different Newcastle disease vaccination programs in Iranian broiler farms: a case-control study

Due to its high prevalence and rapid spread, Newcastle disease is considered a deadly viral disease for the poultry industry worldwide. The uncontrolled and unplanned use of the Newcastle vaccine by poultry farmers reduces its protective value. This study aims to calculate the effectiveness of vaccination programs against Newcastle disease in Iranian broiler farms. The study method is analytical and case-control. One hundred two case farms and 102 control farms were selected for the study. The case farm was defined as a farm with losses exceeding 7%, accompanied by clinical criteria, post-mortem examination, molecular testing, and a history of regional disease outbreaks. The control farms had natural losses (below 7%) and no history of any disease in the current and previous periods. Control farms were matched with case farms regarding capacity, breed, and provincial distribution. The data were analyzed using the chi-square test and multivariable logistic regression analysis. The statistical software Stata version 14 was used for data analysis and modeling. According to the results, the use of the Vitapest strain vaccine by the spray method on day one, followed by the use of the inactivated vaccine by the injection method, and then two doses of the LaSota strain vaccine by the oral route in the program, (87% with a 95% confidence interval of 35-98%), the use of the inactivated vaccine by the injection method and two doses of LaSota strain vaccine by the oral route, (84% with a 95% confidence interval of 23-97%), the use of the inactivated Newcastle disease vaccine at the age of 7–12 days, (78% with a 95% confidence interval of 25-94%), and the use of the live vaccine against Newcastle disease with more than two doses in the program (66% with a 95% confidence interval of 15-88%) were effective. According to the results of this study, inactivated Newcastle disease vaccines are ineffective in the first week, and it is better to administer them at the ages of 7 to 12 days. It is also recommended to use spray vaccines of viscerotropic strains at one day of age to increase mucosal immunity against the Newcastle virus. Finally, principles of biosecurity and farm hygiene management should also be considered to achieve maximum vaccine effectiveness and have a consistent and regular program on the farm.

Effects of Escherichia coli strain Nissle 1917 on immune responses of Japanese quails (Coturnix japonica) to Newcastle disease vaccines.

The development of proper immune responses to Newcastle disease (ND) vaccines is important in controlling the disease. Escherichia coli strain Nissle 1917 (EcN) is involved in regulating the immune system. The current study evaluated the effects of EcN on immune responses to ND live vaccines in Japanese quails. A total of 150 one-day-old quails were divided into three equal groups. Groups A and B received 107 and 106 CFU/ml/day of EcN, respectively, sprayed on their diets, while group C received 1 ml/day of PBS. All birds were vaccinated with B1 and Lasota vaccines at 10 and 20 days of age, respectively. Serum samples were collected in order to assay the levels of IgA and certain cytokines, including IL4, IFN-α, and IFN-γ, as well as antibody titers to NDV by HI and ELISA methods. No significant difference (P>0.05) was observed in serum IgA and IFN-α levels among the groups. However, concentrations of IFN-γ and IL-4 in 42-day-old chicks in group A were significantly (P<0.05) higher than in both other groups. After 15 days of the second vaccination, the mean HI titer following NDV was significantly higher in group A than group C. Groups B and C showed significantly lower HI titer than group A after 22 days of the second vaccination. Mean ELISA titer to NDV was significantly (P<0.05) higher in group A than in groups B and C after 22 days of the second vaccination. It seems that the spraying of 107 CFU/ml/day of EcN on quail diets enhances the immune response to NDV vaccines by increasing serum levels of IFN-γ and IL-4.

Effect of Mycotoxins or Hard Water on Newcastle, Gumboro, and Infectious Bronchitis Post Vaccinal Immune Responses and Performance of Broilers

Viral outbreaks are the leading causes of economic losses in the poultry industries worldwide. Intensive vaccination programs and excellent management are crucial for successful protection. Certainly, the most vital management factors are feed and water quality. This study evaluated the effect of mycotoxins fed or hard water on IBD, ND, and IB vaccines response and performance in broilers. A total of 400 Cobb chicks were randomly divided into 4 groups; not vaccinated negative control (G1), vaccinated positive control (G2), vaccinated mycotoxins fed (G3) and vaccinated hard water (G4). Blood samples were collected at 4, 14, 21, 28, 35 and 42 days of age. Profolk Plus IBD ELISA Kit, Biocheck IB ELISA Kit and Hemagglutination inhibition (HI) test were used for titers estimation. The feed intake, body weight and the feed conversion ratio were calculated. For the effect of mycotoxins, the G3 showed significantly lower mean titers than G2 from the 35th day for all tested vaccines. For the effect of hard water on IBD vaccine response, the G4 had significantly lower mean titers than G2 on the 42nd day. For IB vaccine response, from the 28th day G4 had significantly lower mean titers than G2. Regarding feed intake and body weight, the G2 was significantly better than G3 and G4. In conclusion, mycotoxins had adverse effects on the humoral immune response for IBD, ND, and IB titers. The adverse effect of hard water on IB vaccines response was significant from the 28th day.

Determination of efficacy in inactive Newcastle disease vaccines with an in-vitro method as an alternative to in-vivo methods

Determination of efficacy in inactive Newcastle disease vaccines with an in-vitro method as an alternative to in-vivo methods

Serological responses and protection levels in chickens administered with Newcastle disease vaccines

Vaccination against Newcastle disease (ND) is the most effective means of controlling the disease, and these vaccines are commercialized only after their safety and effectiveness have been verified through tests that comply with Korean Standards of National Lot Release for Veterinary Biologics. This study investigated whether a relatively convenient and safe serological test can be used in place of the challenge test using highly virulent ND virus. Hemagglutination inhibition (HI) assay and enzyme-linked immunosorbent assay (ELISA) were considered positive of log2 2 or more and cutoff value of 200 or more, respectively, in both live and inactivated vaccines. However, when the antibody levels of the live and inactivated vaccines induced using the Ulster 2C, KBNP-C4152R2L, and K148/08 strains were compared, the antibody titers for inactivated vaccines were significantly higher than those for live vaccines in both the HI assay and ELISA. A strong positive correlation was observed between HI and ELISA antibody titers. The live vaccines corresponded to a survival rates of ≥ 80% and the inactivated vaccines corresponded to 100% survival rates. This study confirmed that standard efficacy tests can serve as serological tests, and can replace the challenge test and that the vaccine approval process can be improved.

Effects of dietary supplementation with antibiotic, organic acid, probiotic and prebiotic on the intestinal morphology and Newcastle disease virus titers of broilers in commercial farms

This experiment was carried out to survey the antibody levels against Newcastle disease virus (NDV) and the morphology of ileal villi of broilers in commercial farms. Based on antibiotics and feed additives used, farms were classified in 3 groups as follows (1) Group I was supplied with antibiotic, probiotics and prebiotics; (2) Group II were supplemented with antibiotic, probiotics, prebiotics and organic acids; and (3) Group III was supplied with antibiotic and probiotics. In each farm, ten chicks were sacrificed at day 1, and five chicks were sacrificed at 7, 14, and 28 days old. A total number of 225 Ross 308 broilers at 1, 7, 14 and 28 days of age were selected randomly from nine farms for the titration of antibody against NDV by using Hemagglutination inhibition assay (HI). Furthermore, total 54 ileum samples of chickens on 14 and 28 days old were also collected for measurement of intestinal morphology. The present study showed there were significant differences about the body weights of broilers across farms within the same antibiotics, feed additives and vaccination programs or among different groups at 7, 14 and 28 days of age. However, at the age of 28 days, except Farm 1, 9 (Group I); 4 (Group II) and 3 (Group III), the remaining farms did not meet the criterion of chicken’s body weight. After ND vaccination for broilers at one day old, the mean value of HI antibody titers gradually declined in the first two weeks. Except for Farm 7 and 8, at 14 days old, the remaining farms showed the low antibody titers under 3log2. No significant differences about the antibody titers against ND virus were found in broilers at 28 days of age (P &gt; 0.05) among farms. The findings suggested that the supplementation of antibiotics, probiotics and/or prebiotics and/or organic acids did not have any consistent effects on immune response to NDV and body weights of broilers. However, the morphometric parameters of ileal villi were improved and the positive correlations between body weight and villi height or villi area in ileum segment were found in these chickens.

Assessing the Efficacy of Recombinant Newcastle Disease Virus Vaccines (Double-Insert vHVT-IBD-ND and Single-Insert vHVT-ND) Followed by a Vaccination with a Live Newcastle Disease Vaccine Against a Moroccan Velogenic Newcastle Disease Challenge in Commercial Broilers.

The advent of turkey herpesvirus (HVT) vector vaccine technology (vHVT) has made a huge improvement in the prevention and control of several poultry diseases. The objective of this study was to compare, under experimental conditions, the protection conferred by different vaccination programs based on an HVT double-insert (infectious bursal disease {IBD] and Newcastle disease [ND]) vector vaccine (vHVT-IBD-ND) and an HVT single-insert (vHVT-ND) vector vaccine followed by a vaccination with a live ND vaccine at Day 1 only or at Days 1 and 14. Commercial broilers were vaccinated by the recombinant ND virus vaccines subcutaneously at 1 day old, in the hatchery, and challenged at 30 days of age using the Moroccan ND virus velogenic viscerotropic JEL strain. The results showed that the tested vaccine induced 95% to 100% clinical protection against mortality and clinical signs. The humoral immune response to vaccination was detected from 3 wk of age using enzyme-linked immunosorbent assay and hemagglutination inhibition tests. ND challenge virus shedding was significantly reduced in the vaccinated birds as compared to controls. Significant reduction of the cloacal shedding suggests that the vHVT-IBD-ND vaccine stimulates actively the immunity against the tested ND challenge virus. No significant differences were found between the vaccination programs based on vHVT-IBD-ND or on vHVT-ND.

Beta-glucan enhanced immune response to Newcastle disease vaccine and changed mRNA expression of spleen in chickens

The present study was performed to investigate the effect of oral administration of β-glucan (G70), a product obtained from the cell wall of yeast, on Newcastle disease virus (NDV)-specific hemagglutination inhibition (HI) titers, lymphocyte proliferation, and the role of T lymphocyte subpopulations in chickens treated with live NDV vaccine. In addition, the influence of β-glucan on splenic gene expression was investigated by transcriptome sequencing. The results revealed that the supplementation of β-glucan boosted the titer of serum NDV HI increased the NDV stimulation index of lymphocytes in peripheral blood and intestinal tract, and promoted the differentiation of T lymphocytes into CD4+ T cells. The RNA sequencing (RNA-seq) analysis demonstrated that G70 upregulated the mRNA expressions related to G-protein coupled receptor and MHC class I polypeptide, and downregulated the mRNA expressions related to cathelicidin and beta-defensin. The immunomodulatory effect of G70 might function through mitogen-activated protein kinase signaling pathway. To sum up, G70 could boost the immunological efficacy of live NDV vaccine in chickens and could be applied as a potential adjuvant candidate in the poultry industry.

Evaluation of the anti-Newcastle disease vaccine serum on dogs with canine distemper

Distemper is a contagious, highly lethal, and almost incurable viral disease in dogs and other terrestrial carnivores. This study evaluated a new distemper treatment for dogs. Two healthy male dogs of mixed breed were prepared. A 1 000-dose vial of Newcastle disease vaccine was then diluted with 6 mL normal saline and 3 mL of it was injected into the cephalic vein of each dog, collecting 20 % of the blood volume 11 h later. Blood sera were separated and used as anti-Newcastle disease vaccine serum (ANDVS) to treat dogs suspected of having canine distemper. Dogs with confirmed distemper were grouped into the following seven treatment groups: 1- ANDVS; 2- ANDVS + Cotrimoxazole; 3- ANDVS + Penicillin-Gentamicin; 4- ANDVS + Cefazolin-Amikacin; 5- Cotrimoxazole; 6- Penicillin-Gentamycin; 7- Cefazolin-Amikacin. Then the fatality rate of dogs, association between distemper and sex, breed, age, and effects of distemper on hematological factors and vital signs were evaluated. The recovery rates in the ANDVS+ Cotrimoxazole and the ANDVS+ Cefazolin-Amikacin groups were higher than those in the ANDVS group (P &lt; 0.05). Fatality rate was significantly different in distemper-positive and distemper-negative dogs. It is concluded that although ANDVS alone has no effect on the treatment of distemper, it can increase the recovery rate when combined with cotrimoxazole or cefazolin + amikacin as compared with the sole use of these antibiotics.

Use of Spirulina Platensis in Japanese quail diets in fattening period and responses of performance, meat quality and immunity

This study was carried out to determine the effects of different levels of Spirulina Platensis(SP)in Japanese quails (Coturnix coturnix japonica) diet on performance, meat color, meat quality, and immune response. A total of 250 1-d old Japanese quails were randomly distributed to five dietary groups with five replicates.. The powder form of SP was used and experimental diets formulated according to inclusion levels as; The negative control group (NC)(Basal diet- 0% SP-no vaccine)),the control group (C) (Basal diet, 0%SP -vaccinated) the SP1 group (basal diet-2.5%SP,vaccinated), the SP2 group (basal diet- 5% SP, vaccinated) and the SP3 group (basal diet- 7.5% SP, vaccinated). During five weeks experiment, growth performance parameters were determined and at the end of the trial a total of 75 quails (15 quails from each group) were slaughtered and antibody titers (ABT) against the Newcastle (ND) vaccine, meat color values, meat quality parameters were detected and some visceral organs were weighted. Results showed that the inclusion of SP to quail diets at the level of 2.5% increased the final live weight (FLW) and total body weight gain (TBWG) significantly (P&lt;0.05) compared the other groups. The highest feed consumption (FC) was detected in the control group and the best feed conversion ratio was found in SP1 group (P&lt;0.05). Dietary SP did not affect carcass yield, liver, and bursa weights (P&gt;0.05), however, the carcass weight was affected by SP in the diet and the highest value found in the SP1 group (P&lt;0.05). Color values of breast meat changed as depend on level of the dietary SP and a* and b* values increased by the addition of 2.5%, SP to diet. Breast meat pH value, cook loss (CL), and water holding capacity (WHC) affected by the SP supplementation and the highest values were determined in the control group (P&lt;0.05). ABT reading against the ND vaccine was similar between all vaccinated groups independently from the level of dietary SP but significantly low in the NC group (P&lt;0.05). In a conclusion, the use of SP in quail diets at the level of 2.5 % may positively influence performance, carcass weight breast meat quality parameters, color values.

Effect of different combinations of probiotic, chicory root powder and coriander seed powder on growth, carcass, immunity, serum parameters and economics of broilers

The trial was undertaken in a completely randomized design to to evaluate the synergistic effect of probiotic (Pro), chicory root powder (CRP) and coriander seed powder (CSP) on the performance of broiler chicken. A total of 240 day-old broiler chicks were randomly allotted to six dietary treatments with 8 replicates of 5 birds in each. Treatment groups included T1 as control, i.e. basal diet (BD) without any growth promoter and T2 - BD + antibiotic (BMD @ 500 gm/ton). In the remaining experimental diets, T3 - pro (@ 10 gm/100 kg) + CRP (@ 1.0%), T4 - pro (@ 10 gm/100 kg) + CSP (@ 1.5%), T5 - CRP (@ 1.0%) + CSP (@ 1.5%) and T6 - pro (@ 10 gm/100 kg) + CRP (@ 1.0%) + CSP (@ 1.5%). The results revealed that supplementation of pro + CRP significantly increased the body weight gain during prestarter, starter and finisher phase and improved the feed conversion ratio during finisher phase compared to other treatment groups. Supplementation of different dietary groups did not show any significant effect on feed intake and various slaughter parameters of broilers. Whereas, the humoral immune response to ND vaccine and immune organ weights were significantly higher in all the test diets (T3 to T6) compared to control and antibiotic groups. Supplementation of probiotic with chicory combination group significantly reduced the serum total cholesterol and recorded higher returns over feed cost compared to other treatment groups. It can be concluded that combination of probiotic (10 g) with chicory root powder (1.0%) proved more effective than combinations of other additives.

Using the Women Empowerment in Livestock Index (WELI) to Examine Linkages between Women Smallholder Livestock Farmers' Empowerment and Access to Livestock Vaccines in Machakos County of Kenya: Insights and Critiques.

Livestock diseases are a major barrier to productivity for both male and female livestock keepers in Africa. In Kenya, two of the most devastating livestock diseases are Newcastle Disease (ND) in poultry and Contagious Caprine Pleuropneumonia (CCPP) in goats. Female livestock keepers tend to own more small ruminants (goats, sheep, etc.) and poultry and their livelihoods are adversely affected if their herds are not vaccinated against these diseases. Livestock farming has gender specific challenges and opportunities, with implications for the empowerment of women smallholder farmers, their household well-being, food security, and livelihoods. There is a need to estimate the level to which women benefit personally, socially, and economically from keeping livestock, yet there are very few studies that can measure if livestock production does in fact empower women smallholder livestock farmers. This study was done to examine linkages between women's empowerment and access and control over livestock products and vaccines. The Women Empowerment in Livestock Index (WELI) tool, which was customized to include questions on livestock vaccine access, was used to capture baseline data on empowerment scores for women in Machakos county, Kenya, prior to implementation of animal health and vaccine test models. In total, 400 participants were surveyed in two wards of Machakos County, Kola and Kalama, which were purposively selected. Women's empowerment was mapped to three domains (3DE): intrinsic agency (power within), instrumental agency (power to), and collective agency (power with) measured against adequacy in 13 indicators. Our results indicate that the household structure (female headed or dual headed household), age of respondents and number of members in a household influence the adequacy score. Work balance was the most significant negative contributor to women's disempowerment. Women contributed the most to livestock productive activities and attained adequacy in this area compared to men, directly impacting the WELI score. Women smallholder livestock farmers report low CCPP and ND vaccination rates, minimal knowledge on livestock diseases, a lack of access to cold chain storage and rarely visited veterinarians. The WELI score was 0.81 indicating a high level of empowerment for women in this community compared to men leading us to conclude that the overall WELI score was not an accurate indicator of women's empowerment in Machakos County. However, the decomposability of the index allows us to disaggregate the drivers of change and to examine how individual indicators contribute to disempowerment.

Breaking institutional barriers to enhance women's participation in and benefit from the Peste des Petits Ruminants and Newcastle Disease vaccine value chains for Sembabule district of Uganda.

This paper describes the institutional context that shapes the visibility and positioning of women along the Peste des Petits Ruminants (PPR) and Newcastle Disease (ND) vaccine value chains for Sembabule district of Uganda. It examines the institutional barriers and opportunities that affect women’s empowerment derived from inclusion of women in the decision-making processes along the livestock vaccine value chain (LVVC) and that can support viable women-centered and owned enterprises, at the vaccine development, delivery, distribution and use level. Qualitative data analysis tools such as focus group discussions, focus meals, jar voices and key informant interviews were used. Using outcome mapping, a stakeholder analysis of the critical partners in the PPR and ND value chain was done involving the regulators, vaccine manufacturers, importers, distributors, agrovets, public and private veterinary service deliverers, local leaders, women groups, and farmers. The study concluded that training related to gender equality and livestock vaccines, infrastructural and technical support to the poultry and goat women and men farmers and other chain actors are inadequate in themselves to increase vaccine adoption and improve livestock productivity in Sembabule district. Strategies that promote gender-transformative collaborative efforts among the LVVC actors and build viable gender-transformed women groups and networks are critical to increase women’s participation in and benefit from the livestock vaccine value chain.

The co-administration of live fowlpox and Newcastle disease vaccines by non-invasive routes to chickens reared by smallholders in Tanzania and Nepal

The co-administration of commercial live fowlpox (FP) and Newcastle disease (ND) vaccines when given by non-invasive (needle-free) routes was demonstrated to be safe and to elicit immunity in two field studies, one in Tanzania the other in Nepal. Both studies were of a cluster-randomised controlled design in which birds were randomly assigned to one of five treatment groups: (i) administration with FP vaccine alone (feather follicle), (ii) administration with ND vaccine alone (eye-drop), (iii) concurrent administration of FP (feather follicle) and ND (eye-drop) vaccines, (iv) concurrent administration of FP (wing-web) and ND (eye-drop) vaccines, and (v) unvaccinated, acting as environmental sentinels. Data from a total of 1167 birds from seven villages in Hanang District of Tanzania together with 1037 birds from eleven villages in Dhading District of Nepal were collected over a period of 21 and 28 days, respectively. Immune responses to FP vaccination were evaluated by local take reactions, while those to ND vaccination were evaluated serologically by haemagglutination inhibition test. The two studies demonstrated that the concurrent vaccination of free-range, indigenous breeds of chicken with live FP and ND vaccines, both administered by non-invasive routes, was safe and induced immunity against FP and ND that were non-inferior to the administration of FP and ND vaccines alone. These findings are important to appropriately trained small-scale backyard poultry farmers as well as to paraprofessionals and community health workers helping to increase vaccine uptake and the control of both FP and ND in low- to middle-income countries.

In ovo nano-silver and nutrient supplementation improves immunity and resistance against Newcastle disease virus challenge in broiler chickens.

Silver nanoparticles (AgNPs) interact with the microbes and host immune system to protect against diseases. Fertile broiler eggs (n = 900) were allotted to six groups: un-injected control, sham (sterile water), AgNPs (50 μg), AgNPs+Amino acids (Methionine-10 mg + Arginine-25 mg), AgNPs+Vitamins (Vit B1-72μg + Vit B6-140μg), and AgNPs+Trace Elements (Zn-80 μg and Se-0.3 μg) and incubated for 18 days. On 18th embryonic day, 0.6 ml test solution was injected at the broad end of egg using 25 mm needle and transferred to hatcher. Post-hatch, half of the chicks from each group were vaccinated with Newcastle disease (ND) vaccine, and the other half were kept as unvaccinated unit and reared for 42 d with standard management practices. Hatchability, 1st and 42nd d body weight, feed intake, and feed conversion ratio were similar between treatment groups in both vaccinated and unvaccinated units. The relative weight of bursa Fabricius and thymus was similar, but spleen weight was higher (P ≤ 0.05) in AgNPs, AgNPs+Vits, and AgNPs+TEs chicks than control group. Cellular immune response (against mitogen phytohemagglutinin-P) was higher (P ≤ 0.05) in AgNPs+TEs chicks, whereas HA titer against sheep red blood cells antigen, serum IgG, IgM, and HI titer against ND vaccine was apparently higher in AgNPs+Vits group chicks than control. No clinical symptoms were observed in the vaccinated groups except for a few control birds 6 days postchallenge (PC). Three days PC, unvaccinated birds show depression, off feed, greenish diarrhea, and nasal discharge and the control group started dying. The highest cumulative infection (CI) was observed in sham (79.17%) and un-injected control (75%), but lowest in AgNPs+AAs birds (58.33%) on 3rd dpi. The CI reached 100% on 5th dpi in control groups and AgNPs, and 91.67% and 93.75% in AgNPs+TEs and AgNPs+AAs group, respectively. The AgNPs+TEs and AgNPs+AAs group birds lived for more than 90 h compared to 75 h in control groups and also had higher IL-6 and IL-2 gene expressions at 24 h PC. It was concluded that 50 μg/egg AgNPs with vitamins (B1 and B6) and trace elements (Zn and Se) improved performance, but AgNPs with trace elements and amino acids enhanced immune response and resistance against vND virus challenge in broilers.

Effect of in ovo administration of Newcastle disease vaccine conjugated with Astragalus polysaccharide on growth performance, intestinal development, and mucosal immunity in broiler chickens.

This study was conducted to investigate the effect of in ovo administration of a mixture of Astragalus polysaccharide (APS) and Newcastle disease vaccine (NDV) on growth performance, intestinal development, and mucosal immunity in newly hatched chicks. Six hundred specific-pathogen-free (SPF) Leghorn fertilised eggs were incubated in a commercial hatchery and divided into four groups: (a) control group injected with 1 ml of 0.9% physiological saline, (b) APS group injected with 1 ml of 1 mg/ml APS solution, and (c) NDV group injected with 1 ml of 104.0 EID50 /dose of NDV solution, and (d) APS + NDV group injected with a mixture of 0.5 ml of 2 mg/ml APS plus 0.5 ml 104.0 EID50 /dose ND vaccine (NDV) on Day 18.5 of incubation. The results showed that in ovo injection of APS or the mixture of APS and NDV increased the body weight at 1 day (IW) and final weight (FW) at 28 days and increased the feed conversion ratio (FCR) at 1-7, 8-14, 15-21, and 1-28 days of age. The villus height (VH) was increased (p < 0.05), and the crypt depth (CD) was decreased (p < 0.05) in the duodenum compared with the control group. The VH/CD ratios were increased (p < 0.05) in the APS + NDV group compared with controls, NDV group, and APS group on d3. The levels of slgA in washings were increased (p < 0.05) on Days 3, 7, 14, 21, and 28, and the number of IgA+ cells in the duodenum was increased on Days 7, 14, 21, and 28. In addition, the IgA+ cells were promoted from the villus root to the apex in the APS + NDV group. It can be concluded that in ovo administration of NDV conjugated with APS compared with NDV alone may be more effective in promoting growth performance and intestinal mucosal immunity.

Effect of Age and Presence of Maternal Antibodies on Success of Avian Influenza and Newcastle Disease Vaccinations in Broiler

Avian Influenza (AI) and Newcastle Disease (ND) are viral infections that attack poultry worldwide. AI outbreaks in Indonesia were first reported in 2003, which led to the death of millions of birds, while ND is an endemic disease. Vaccination control of these diseases has been carried out, but cases are still being reported in poultry. Therefore, this study aims to determine the effect of age and the presence of maternal antibodies on the success of vaccination using the AI H5N1 and the ND vaccine. It was conducted using a tiered randomized block design with 3 treatments group and 10 replicates. The tiered pattern of antibody examination was carried out at pre-vaccination, followed by 7, 14, and 21 days after vaccination. Furthermore, antibody measurements were carried out using the hemagglutination inhibition (HI) test. The results showed that age had no significant effect as demonstrated by P&gt;0.05 on antibody titer after AI vaccination, given that the chickens at the time of vaccination had unprotected maternal antibodies. Meanwhile, age affected the ND antibody titers because the chickens with maternal protective antibodies at the time of vaccination showed lower ND antibody titers (P&lt;0.05). AI vaccination in broilers without maternal antibodies showed a good response to antibody development, while protective maternal ND antibodies interfered with the formation of ND antibodies caused by vaccination. Based on the results, the age at vaccination and the presence of maternal antibodies greatly affects the antibody titers produced by the vaccine. Therefore, it is important to consider the timing of vaccination when maternal antibodies level decreased then vaccine should be administered to avoid neutralization.