Inactivated Newcastle Disease Vaccine Research Articles

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.

Effect of Oregano Essential Oil Combined with Live and Killed Newcastle Disease Vaccines on Immune Response in Broilers Chicks in Erbil, Iraq: A Comparative Study.

This trial was conducted to evaluate the effects of oregano essential oil supplementation at the concentration of 50 mL/1000L of drinking water on immune response and growth performance in broiler chickens. A total of 390 one-day-old Rose chickens were housed together in six experimental boxes (n=65 each), including non-vaccinated groups and non-vaccinated oregano treated groups. Group A: vaccinated with LaSota vaccine via eye drop at 5-, 15-, and 28-day-old adding oregano essential oil in drinking water 1 day post-vaccination. Group B: vaccinated with LaSota vaccine via eye drop at 5-, 15-, 28-day-old only without oregano essential oil. Group C: vaccinated with inactivated Newcastle disease (ND) vaccine at 5-day-old via subcutaneous (SC) injection one dose adding oregano essential oil in drinking water 1 day post-vaccination for 3 days. Group D: vaccinated with inactivated ND vaccine at 5-day-old via SC injection one dose only without oregano essential oil. Group E: non-vaccinated as the control group. Group F: non-vaccinated and adding oregano essential oil for 3 days in drinking water as the control group. The effect of oregano essential oil in drinking water combined with two forms of live and killed ND virus vaccines on the immune responses and serum proteins was investigated in broiler chickens. The results showed the significant effect of oregano on the immune response of chicks in groups D and C that were vaccinated with the killed vaccine at 23- and 33-day-old. Based on the findings, a peak was recorded at 38-day-old with a significant difference (P<0.05) in vaccinated and non-vaccinated groups, as well as a significant increase in 38-day-old for group C (P<0.05), compared to other groups regarding the oregano effects on the immune response of groups. In addition, an increase in the serum protein was significantly different (P0.05) in the vaccinated broiler chicks, and serum globulin showed a quantitative increase in the vaccinated broiler chicks, compared with non-vaccinated groups. However, the results showed that the effect of oregano was non-significantly different (P>0.05) and it had no beneficial effect on growth performance. The results of this study showed the effects of commercial Oregano supplementation (50 mL/1000L drinking water), which increased serum total protein, including globulin, and provoked the best immunological response to ND vaccinations in broiler chickens. More research is needed to develop a state that may beneficially affect the health and uniformity of chickens.

Immunological evaluation of inactivated Newcastle disease vaccine depending on adjuvant composition

Newcastle disease is a global problem that is being recorded in most countries and also a serious obstacle to exchange of genetic material of poultry in various countries of the world. Control of the Newcastle disease comprises correct injection of efficacious vaccines so as to decrease or eliminate the clinical disease. Our goal was to perform comparative studies of the vaccines against Newcastle disease of water in oil type, the adjuvant being mineral oil mixed with emulsifiers (Span-80 and Tween-80) and ready-to-use adjuvant system (Montanide ISA 70), and study the impact of composition of adjuvant constituent on physical-chemical and immunogenic properties of inactivated vaccines. To reproduce virus-containing material and carried out titration of the viruses, we used chicken embryos free of pathogenic microflora. Aqueous phase for the preparation of emulsion-based vaccines of water in oil type consisted of antigen to Newcastle disease of La-Sota strain, manufactured by Biotestlab Ltd, and phosphate-saline buffer. To evaluate the effectiveness of the vaccine and induce immune response, we used 1-day old pathogen-free chickens, which were obtained from chicken embryos free of pathogenic microflora. As the positive control in the experiment, we used commercial vaccine. One-day chickens were divided into 3 groups (I, II, III) comprising 12 individuals each and one group (IV) consisting of 8 individuals as the control group with individual numeration. Chickens in groups I, II and III were divided into two subgroups (n = 8 and n = 4) to determine immunogenic efficiency and safety of the vaccine. Immunization was carried out through single subcutaneous injections in the region of the neck. To study immunogenic efficiency, the chickens were immunized with the dose of 0.1 mL (1 dose), and 0.2 mL (2 doses) to determine safety. After the immunization of 1-day old pathogen-free chickens with 0.1 mL dose, the obtained level of antibodies in the serum of vaccinated chickens on days 14, 21, 28, 35 and 42 after the vaccination indicated the ability of provoking the immune response to Newcastle disease at high level and safety of the vaccination for chickens. All the recipes of the examined series of the vaccines and the commercial vaccine produced appropriate level of viscosity according to the criterion equaling ≤ 200 mm2/s at Р &lt;0.05, promoting fluidity of the vaccine and providing easier passage through the needle during the application. Both of the studied vaccines may be used in poultry farming for prophylaxis of Newcastle disease among chickens.

Comparison of flagellin and an oil-emulsion adjuvant in inactivated Newcastle disease vaccine in stimulation of immunogenic parameters

The present study was designed to investigate the potential application of native (N) and recombinant (truncated modified [tmFliC] and full-length [flFliC]) flagellin proteins along with inactivated Newcastle disease virus (NDV). Fifty six SPF chickens were immunized twice with PBS (control), inactivated NDV (Ag), inactivated NDV/flFliC (AgF), inactivated NDV/tmFliC (AgT), inactivated NDV/N (AgN), commercial vaccine containing Montanide (Vac) and Vac/N (VacN), with a two-week interval. Blood was collected weekly and spleens were harvested after chickens were sacrificed. Interleukin-6 (IL-6) and tumor necrotic factor-α (TNF-α) gene expression in peripheral blood mononuclear cells were analyzed by Real-Time PCR. Antibody response was assessed by haemagglutination inhibition (HI). Cellular activity was quantified by MTT assay. Results showed that the most IL-6 and TNF-α gene expression was observed in AgF group (P < 0.01). The lowest gene expression among vaccinated groups was observed in Ag group for IL-6 and Ag and Vac group for TNF-α. The highest HI titer was observed in Vac, VacN, AgF and AgT groups. The AgF group showed the highest cellular activity (P < 0.01). In conclusion, flagellin-adjuvanted groups showed a pro-inflammatory effect and acted similarly to or better than the Vac group. Hence, flagellin can be proposed as a potential adjuvant for ND vaccine.

Development, Biological Characterization, and Immunological Evaluation of Virosome Vaccine against Newcastle Disease in Pakistan.

Newcastle disease (ND) is a highly fatal, infectious, viral disease, and despite immunization with live and inactivated vaccines, the disease is still endemic, causing heavy morbidity and mortality leading to huge economic losses to the poultry industry in Pakistan. Therefore, the present study was aimed for the first time in the country at using novel virosomal technology to develop the ND vaccine using an indigenous highly virulent strain of the virus. ND virosome was prepared using Triton X-100, and SM2 Bio-Beads were used to remove the detergent and reconstitute the viral membrane into virosome. Confirmation was done by transmission electron microscopy and protein analysis by SDS-PAGE. In vitro cell adhesion property was observed by incorporating green fluorescent protein (GFP), producing plasmid into virosome and in vitro cell culture assay. Sterility, safety, and stability of the vaccine were tested before in vivo evaluation of immunogenicity and challenge protection study in commercial broiler. The virosome vaccine was administered (30 μg/bird) at days 7 and 14 through the intranasal route in comparison with commercially available live and inactivated ND vaccines. Results revealed significantly high (p < 0.05) and clinically protective hemagglutination inhibition (HI) antibody titers at 7, 14, 21, and 28 days postimmunization with the virosome vaccine in comparison to the negative control. The GMTs were comparable to live and inactivated vaccines with nonsignificant (p > 0.05) differences throughout the experiment. Antibody levels increased in all vaccinated groups gradually from the 7th day and were maximum at 28th-day postvaccination. In the virosome-administered group, GMT was 83.18 and 77.62 at 21st and 28th-days postvaccination, respectively. Challenge revealed 100%, 90%, and 80% protection in virosome, live, and inactivated vaccinated groups, respectively. Under given experimental conditions, we can conclude that ND virosome vaccine prepared from the indigenous virus was found to be safe and immunogenic.

Synthesis and antiviral activity of some pyrrolonyl substituted heterocycles as additives to enhance inactivated Newcastle disease vaccine

This research reported the design and synthesis of some influential new pyrrolone derivatives bearing a pyrazole scaffold with the evaluation of their antiviral activity against Newcastle disease virus (NDV) in specific pathogen free (SPF) chicken embryos and immune boosting properties of these substances in SPF chicks. The building block synthon was the pyrazolyl acid hydrazide, derived from 2(3H)-furanone, which was reacted with some carbonyl compounds, e.g., salicylaldehyde, furfural, 1,3-diphenylpyrazole-4-carbaldehyde, 2-chloroquinoline-3-carbaldehyde, chromone-3-carbaldehyde, and 3-acetylcoumarin. The results revealed that pyrazole derivative 6, quinoline derivatives 7 and 8 exhibited 100% protection against NDV while the hydroxyphenyl derivative 3 showed 95% protection. In turn, chromone derivative 10 and coumarin derivative 11 exhibited 90% protection. The structures of all products were established on the basis of their elemental analyses and spectroscopic techniques.

Enhancement in humoral response against inactivated Newcastle disease vaccine in broiler chickens administered orally with plant-derived soyasaponin

The present study aimed to evaluate the immunopotentiating effect of plant-derived soyasaponin and its immunogenicity in chickens challenged with Newcastle disease virus (NDV). Soyasaponin was extracted from soybean seeds and detected using the phytochemical tests, followed by quantification through the dry-weight method. One-day-old broiler chicks (n = 90) were divided into 3 groups, named as A, B, and C. Group A birds were orally administrated with soyasaponin (5 mg/kg), followed by immunization with inactivated ND vaccine intramuscularly (IM), whereas group B birds were vaccinated with inactivated ND vaccine alone. Group C birds were kept unvaccinated. A booster dose on day 21 was also administered IM to group A and B birds. At day 35, all 3 groups were challenged with NDV. To determine the immunogenicity potential of soyasaponin, antibody titer was measured using the hemagglutination inhibition test before and after the NDV challenge. Histochemical examination was performed to determine the pathological changes associated with NDV infection. Foam formation and hemolytic activity confirmed the presence of saponin in soya bean extract. Group A birds showed a higher antibody response compared with group B and C birds. The disease challenge study showed that soyasaponin-adjuvanted NDV vaccine provided complete protection to group A birds against ND. Moreover, no side effects of soyasaponin were observed on the growth performance of birds during the experiment. Therefore, we can conclude that soyasaponin is a potential immunogenic agent and therefore could be a promising candidate to launch a protective humoral response against ND in chickens.

Effects of vaccination on acute-phase protein response in broiler chicken.

Broiler chickens experience an acute-phase response (APR) through vaccination, which reflects the innate immunity and stress related to immunization. It is also considered that APR can modulate adaptive immunity and response to infection. As biomarkers for APR, assessing the acute-phase proteins (APPs) function and their levels in response to immunization is of great value for vaccine design, development and administration. In this study, the heterophils/lymphocyte (H/L) ratio and the level of APPs was evaluated in broilers with three different Newcastle disease (ND) vaccination regimens. Inactivated ND vaccine (IND) was administered by the intramuscular route. Live attenuated strains, Lasota and Vitapest, was administered by ocular routes. H/L ratio, serum amyloid A (SAA) and alpha-1 acid glycoprotein (AGP) were measured before and after two rounds of vaccination on days 10 and 21. In a comparison between the three vaccines, H/L ratio in IND group significantly increased to 3 fold (1.48 ± 0.41) after the first vaccination while the Lasota and Vitapest showed a milder response. The concentration of SAA increased after 24h by 1.8-fold in IND group (0.116 ± 0.015 mg/L) and 2-fold in Lasota group (0.14 ± 0.002 mg/L). Significant changes were found in Vitapest group after 48h post vaccination (0.113 ± 0.016 mg/L). Elevation pattern of AGP, 24 hours after first vaccination in IND (3.5-fold) and Vitapest (2.5-fold) was different from Lasota in which the peak was reached after 48 hours (2.9-fold). Except for IND group, no significant changes in SAA and AGP concentrations were detected after the second vaccination. A significant positive correlation between SAA values at day 22 and HI titers at day 28 (r = 0.998, P≤0. 0.005) was found. According to these results, different types of ND vaccines can cause different patterns of acute phase responses. Assessment of stress and level of acute-phase proteins can be used for prediction of immune response outcomes in vaccine design and development.

Pathogenesis of Newcastle Disease Virus Genotype VII in Chickens Vaccinated with LaSota and Inactivated Newcastle Disease Vaccines

Newcastle disease (ND) is one of the most serious viral diseases affecting poultry farms in different countries. Many outbreaks -even in vaccinated poultry flocks- were recorded in the last few years caused by Newcastle disease virus (NDV) genotype VII. This study was conducted to compare the pathogenesis of NDV genotype VII in non-vaccinated chickens and chickens vaccinated with NDV genotype II live (LaSota) and inactivated vaccines. One hundred 1-day-old chicks were divided into four equal groups; 25 for each. Groups A and B were kept unvaccinated. Group C was vaccinated with LaSota, and group D was vaccinated with both LaSota and inactivated NDV vaccine. Group A was kept as nonchallenged control blank group, while groups B, C and D were challenged intranasally by 0.1 ml 106 EID50 NDV genotype VII at 25-day of age. Three chickens were sacrificed from each group at 2, 5- and 10-days post challenge (dpc). Tissue specimens from trachea, lungs, bursa of fabricius, spleen and thymus were collected for histopathology and immunohistochemistry. NDV genotype VII challenge virus did not induce mortality in both vaccinated groups. Both vaccination programs resulted also in less severe clinical signs and histopathological lesions comparing to non-vaccinated challenged birds. Tracheal lesion score was significantly low in group D at 10 dpc while no significant difference was recorded between groups C and D in lungs. All lymphoid organs showed significantly less severe pathological alterations and depletion in groups C and D comparing to group B. Our results indicated that mis-matched genotype NDV vaccines could alleviate the pathological effect of the NDV challenge virus but do not provide complete protection of the infected host organs.

Preparation of the inactivated Newcastle disease vaccine by plasma activated water and evaluation of its protection efficacy

Vaccination has been regarded as the most effective way to reduce death and morbidity caused by infectious diseases in the livestock industry. In this study, plasma activated water (PAW) was introduced to prepare the inactivated Newcastle disease vaccine. Humoral immune response was tested by hemagglutination inhibition (HI) assay and enzyme-linked immunosorbent assay (ELISA). In addition, cell-mediated immune response was evaluated by lymphocyte proliferation assay and flow cytometry. The results demonstrated that the vaccine prepared by PAW at appropriate volume ratio could induce similar antibody titers in specific pathogen-free (SPF) chickens compared with the formaldehyde-inactivated vaccine. The challenge experiment further confirmed that the vaccine prepared by PAW conferred solid protection against virulent NDV. Moreover, it was found that the vaccine could promote the proliferation of lymphocytes and stimulate cell-mediated immunity of SPF chickens. Furthermore, analysis of electron spin resonance (ESR) spectroscopy and physicochemical properties of PAW suggested reactive oxygen and nitrogen species (RONS) played an essential role in the virus inactivation. Therefore, this study indicated that NDV treated by PAW in an appropriate ratio retained immunogenicity on the premise of virus inactivation. PAW as a promising strategy could be used to prepare inactivated vaccine for Newcastle disease.

Chitosan, hydroxypropyltrimethyl ammonium chloride chitosan and sulfated chitosan nanoparticles as adjuvants for inactivated Newcastle disease vaccine

Chitosan (CS) and its water-soluble derivatives, hydroxypropyltrimethyl ammonium chloride chitosan (HACC) and sulfated chitosan (SCS), were used as adjuvants of inactivated Newcastle disease (ND) vaccine. First, NDV-loaded and blank CS, HACC/CS and SCS nanoparticles were prepared. The particle sizes were respectively 343.43 ± 4.12, 320.03 ± 0.84, 156.2 ± 9.29 nm and the zeta potentials were respectively +19.67 ± 0.58, +18.3 ± 0.5, −17.8 ± 2.65 mV under the optimal conditions. Then chickens were immunized with nanoparticles or commercial inactivated oil emulsion vaccine. After immunization, the humoral immunity levels of the chickens were evaluated. The cellular immunity levels were determined by the quantification of cytokines, lymphocyte proliferation assay, the percentages of CD4+ and CD8+ T lymphocytes. Finally, the chickens were challenged with highly virulent virus. The results demonstrated that the humoral immunity levels in NDV-loaded CS and HACC/CS nanoparticles groups were lower than commercial vaccine but the cellular immunity levels are better. Moreover, the prevention effects of NDV-loaded CS and HACC/CS nanoparticles against highly virulent NDV are comparable to commercial vaccine. Our study provides the basis of developing HACC and CS as effective vaccine adjuvants.

Genotypes II and VIId-based inactivated Newcastle disease vaccine reduces virus shedding.

In Egypt, recent outbreaks were reported in NDV-vaccinated flocks. The isolated strain was characterized as class II velogenic genotype VIId of Newcastle disease virus (NDV). In this study, three inactivated NDV vaccine formulations were prepared, the first one is LaSota (genotype II), the second one is genotype VIId and the third one is combined Lasota and genotype VIId at a proportion of 1:1. The challenge trials were conducted in SPF chicks to evaluate the efficacy of the prepared vaccines using 106 EID50/0.5ml of the Egyptian genotype VIId strain of Newcastle disease virus (NDV-B7-RLQP-CH-EG-12). Our results revealed that all three prepared vaccine formulations conferred 100% protection in the vaccinated chicks. However, the combined vaccine induced the highest haemagglutination inhibition (HI) titers and neutralization indices with significant reduction in virus shedding compared to other vaccine formulations. Histopathology examination of different organs collected from vaccinated chicks post challenge indicated the protective efficacy in vaccinated groups compared to the positive control group where a score of severe lesions was shown. This study reports the efficacy of combined inactivated Lasota and genotype VIId vaccine in reducing virus shedding which is very important in controlling NDV infection in chicken.

Comparative study on locally produced bivalent inactivated Newcastle disease vaccine in broiler chicks

Comparative study on locally produced bivalent inactivated Newcastle disease vaccine in broiler chicks

Enhancement of cell-mediated immune response in chickens by combination of TIR-TLR7 with inactivated Newcastle disease vaccine

Enhancement of cell-mediated immune response in chickens by combination of TIR-TLR7 with inactivated Newcastle disease vaccine

Preparation and immune in chickens of pulsatile delivery system for inactivated Newcastle disease vaccine

Due to the weak immunogenicity, traditional inactivated vaccines need to use adjuvants and multiple doses to generate effective immune protection. Therefore, in theory and practice, it is valuable to develop a vaccine delivery system with an adjuvant effect, which can be carried out in a single dose. In view of this, inactivated Newcastle disease virus (NDV)-loaded poly (lactic-co-glycolic acid) (PLGA) microspheres with different release characteristics were prepared. Two release peaks of four groups of microspheres were observed during in vitro release test. The first release peak came out on the first day. The second release peak of A microspheres appeared at the 7th week. The second release peak of B microspheres appeared at the 5th week. The second release peaks of C and D microspheres all appeared at the 11th week. The release of C microspheres contrast to D microspheres was more smooth at release peak, so A, B, C microspheres were selected to construct the pulsatile system. Thus inactivated Newcastle disease(ND) vaccine pulsatile release systems using an appropriate combination of vaccine microspheres with a suitable release characteristics was constituted . Then their immune effects on chickens were evaluated. Chickens without maternal antibodies against NDV were grouped randomly and then immunized with NDV-PLGA microsphere vaccine and inactivated ND vaccine respectively. The results show that inactivated NDV-PLGA microsphere vaccine had the effect of pulsatile release in chickens and were able to maintain high and constant antibody level. And the pulsatile release system composed of mixed microspheres had the best immune effect. This study demonstrated that inactivated NDV-PLGA microsphere pulsatile release system with reasonable release interval could realize effective immune protection in a long time by a single injection. This was the first ever report on PLGA microspheres-based pulsatile release system for inactivated NDV vaccine.

Effect of Hatching Eggs Injection with Inactivated Newcastle Disease Vaccine and Two Doses of Cod Liver Oil on some Productive Traits and Immune Response of Broilers

Effect of Hatching Eggs Injection with Inactivated Newcastle Disease Vaccine and Two Doses of Cod Liver Oil on some Productive Traits and Immune Response of Broilers

Plaque formation of Quesland V4 lentogenic strain of Newcastle disease virus adapted in chick embryo fibroblast cells

Vaccination is one of the important methods for preventing and controlling of the Newcastle disease in Iran. Inactivated Newcastle disease vaccine is produced in the Razi Vaccine and Serum Research Institute, Iran, and is mainly used for vaccination against Newcastle disease. Clone vaccines are used in many countries nowadays. One of the ways for cloning a virus is propagation of the virus on cell cultures to obtain discrete plaques. In this study, monolayer chick embryo fibroblast (CEF) cell cultures were prepared by a standard method. Monolayer CEF cells were used for plaque production trial. Confluent monolayer CEF cells were in tissue culture plates and inoculated with avian paramyxovirus-1/chicken/Australia/Queensland/V4/1966 (QV4) (V4 seed of Newcastle vaccine) with 109.7 50 % egg infection dose. Various dilutions of the viruses were inoculated into monolayer CEF cell cultures that were supplemented with magnesium sulfate and trypsin and agar overlay medium. No plaques were observed on CEF tissue culture plates inoculated with V4 strain without adaptation. Eight discrete large and small plaques were obtained in the 10−5 dilution of adapted viruses (titer 3 × 107 plaque-forming units (PFU)/ml) with 2–4 mm diameter at 80 h post inoculation, and in the 10−7–10−10 dilution, there was no any plaque obtained. A dilution of 10−4 produced 28 plaques (1.75 × 108 PFU/ml) but not discrete plaque, and at 10−1–10−3 dilution, plaques were too much that they were not countable. Eight various plaques at 10−5 were collected and propagated for further investigations. The present assay is a useful tool for demonstration of discrete plaques using the adapted v4 of Newcastle disease virus within 3 days on monolayer CEF cell cultures covered with modified overlay media containing magnesium ions, diethylaminoethyl dextran, and ionoagar to ascertain the purity. This technique for plaque formation by v4 of Newcastle disease virus provides a method for establishing the purity of seed stock used in the production of vaccine.

COMPARATIVE EVALUATION OF THE PROTECTIVE EFFICACY OF DIFFERENT VACCINATION PROGRAMS AGAINST A VIRULENT FIELD STRAIN OF THE NEWCASTLE DISEASE VIRUS IN BROILERS

Despite the intensive vaccination programs used for controlling Newcastle disease (ND) in the Iranian poultry industry, outbreaks of ND have been reported in poultry farms. This study was conducted to evaluate the effectiveness of vaccines for the protection against ND infection and virus-shedding period of velogenic Newcastle disease virus (vNDV) field strain after different immunization schemes. Eight groups of commercial broiler chickens were used. Six groups were vaccinated with different vaccination programs using commercial live and inactivated ND vaccines. All groups, except for group 8, were challenged with a virulent field isolate (104EID50/bird) at 28 days of age. Clinical signs, mortality rate and gross lesions were investigated. Antibody titers were assayed by hemagglutination inhibition test and fecal virus shedding was determined for 14 days post challenge (dpc) with 3-day intervals by the RT-PCR method. All unvaccinated-challenged control birds died. Vaccination with these ND vaccines protected chickens from clinical disease. The mortality rate in the vaccinated groups was significantly lower than in the positive control group. However, vaccinated chickens shed the challenge virus in fecal samples. Although the different vaccination regimens displayed close degrees of protection against the disease, the best protection was observed in broilers primed with the live B1 vaccine via eye drop simultaneously with inactivated vaccine at 8 days of age and boosted with B1 or LaSota via drinking water on day 18. In conclusion, the currently used vaccines with different vaccination schemes can protect chickens against the disease in areas where ND is endemic, while the spread of the field virus to other flocks cannot be prevented.

FIELD EVALUATION OF NEWCASTLE DISEASE VACCINE OF VG\GA IN STRAIN SEVERAL COMMERCIAL BROILER FARMS IN JAVA

This field evaluation was conducted to study the level of protection, post vaccinal reactions and zootechninal performance of groups of chickens which have been vaccinated with Newcastle disease (ND) vaccine of VG/GA strain.This evaluation was done in 26.000 broilers from 4 farms, which have different condition in management practices and were located in different areas of Java.Chickens were vaccinated with VGAGA vaccine or with B-l/La Sota vaccine with/without inactivated ND. Serological tests were done at the age of 28 and 35 days, whereas challenge test with local ND virus isolates was done at the age of 45 days. Results of field evaluation indicated that in broilers, the VG/GA vaccine induced a high level of protection agamst the challenge test with a local (Indonesia) ND virus isolate and against infection with field ND virus. Statistical analysis indicated that the hemagglutination inhibition (HI) titers against NDV were significantly higher (P &lt; 0,05) in group of chickens vaccinated with VG/GA with/without inactivated ND compared to group of chickens vaccinated with B-l/La Sota with/without inactivated ND vaccine. In certain conditions, the post vaccinal reactions were milder and the zootechnkal performance was better in groups of chickens vaccinated with VG/GA strain compared to groups vaccinated with B-l/La Sota.

Effect of injection hatching eggs with Newcastle disease vaccine and different doses of vitamin E on some productive traits and immune response of broilers

This study aimed to investigate the effects of injection hatching eggs with different doses of vitamin E on productive traits, some physiological and immune response to Newcastle disease vaccine. Two hundred fertile eggs of broiler breeder Ross (308) strain were incubated in automatic incubator machine after divided into four treatments (50 eggs per treatment) with two replicates. First treatment was injected 0.1ml/egg of phosphate buffer sterile into amniotic fluid at day 18th of incubation which it was considered as control group, second treatment was injected with 0.1ml/egg of inactivated Newcastle disease vaccine, third treatment was injected with 0.1ml/egg of inactivated Newcastle disease vaccine and 0.1 ml/egg of vitamin E, fourth treatment was injected with 0.1ml/egg of inactivated Newcastle disease vaccine and 0.15 ml/egg of vitamin E. All injected eggs were carried back into incubator for complete hatching process. Hatched chicks were transferred to the hall in farm of the Veterinary Medicine College/University of Baghdad; therefore, the chicks were distributed into four treatments with two replicates depending on the previously treated groups until fifth week of age. The results revealed that the treated groups with vitamin E were significantly (P≤0.05) increased in hatchability percentage, body weight, weight gain, as well as significant reduce in feed intake and improvement in feed conversion ratio as compared with second group and control, the results of third group showed significantly increased (P≤0.05) in antibody titers against Newcastle disease virus at aged (21 and 35) day as compared with the other treated groups and control.