Inactivated Newcastle Disease Virus Research Articles

Evaluation of formaldehyde and binary ethylenimine inactivated Newcastle Disease Virus Vaccine from new isolate compared with imported NDV vaccine

Even massive vaccination programs, the incidence of Newcastle Disease virus (NDV) outbreaks in Egypt is still frequent with appearing new isolates that need production of new vaccines. In this study, NDV vaccine was prepared by using a new local isolate (NDV/Ch/Giza2014) inactivated by two different chemicals binary ethylenimine (BEI) and formaldehyde. The formaldehyde inactivated NDV (NDVF), BEI inactivated NDV (NDVEI) and imported inactivated Newcastle Disease virus (NDVI) vaccines were examined for generating humoral immune response in different groups of specific pathogen free (SPF) chicks. Vaccinated Chicks by NDVEI vaccine gave higher serum antibody titers than NDVF and NDVI Vaccines using Haemagglutination Inhibition (HI) test. The prepared and imported vaccines gave near percentage of protection against the local and the classical strain in chicks. It could be concluded that the locally prepared inactivated NDV vaccines can protect chicken against either homologous or heterologous challenging viruses and the NDVEI Vaccine gave higher protection percentage than NDVF and NDVI Vaccines.

Efficacy of an inactivated Vaccine prepared from a new isolate of Newcastle Disease Virus

The incidence of Newcastle Disease virus (NDV) outbreaks in Egypt is still frequent even massive vaccination programs that due to viral mutation and appearing new isolates that need new vaccination program. Inactivated Newcastle Disease virus (NDV) vaccine was prepared using a new local isolate (NDV/Ch/Giza2014), from Giza governorate, Egypt, inactivated with binary ethylenimine (BEI) and emulsified with Montanide ISA70VG as an oil adjuvant. The prepared vaccine was evaluated in comparison with an inactivated imported vaccine. Chick groups vaccinated with either prepared or imported vaccines showed high serum antibody titers from the third week post vaccination until reached the maximum titer at the 9th week post vaccination using Haemagglutination Inhibition (HI) test. The prepared and imported vaccines gave 95-100% of protection against the local and the classical strain in chicks, during challenge period, there no clinical signs or lesions on examination. Our Conclusion that the locally prepared inactivated NDV vaccine can protect chicken against either homologous or heterologous challenging viruses.

Sunflower seed oil containing ginseng stem–leaf saponins (E515-D) is a safe adjuvant for Newcastle disease vaccine

Vaccination is an effective method to prevent Newcastle disease (ND) in chickens. Marcol 52 and #10 white oil are mineral-based adjuvants and can be found in commercial inactivated ND virus vaccines. The present study demonstrated that a vegetable origin oil E515-D had lower polycyclic aromatic hydrocarbons and higher flash point than the commercial products Marcol 52 and #10 white oil. E515-D could be mixed with an aqueous phase containing ND virus antigen to form a stable water-in-oil vaccine emulsion and exhibited more potent adjuvant effects on the immune response than Marcol 52 and #10 white oil. Moreover, the absorption of E515-D–adjuvanted vaccine was faster than absorption of Marcol 52- and #10 white oil-adjuvanted vaccines when ND virus vaccines were injected in broilers. Therefore, E515-D was safe and could be a suitable adjuvant used in vaccines for food animals. In addition，E515-D is not easy to be flammable during shipping and storage owing to its higher flash point.

Sunflower seed oil combined with ginseng stem-leaf saponins as an adjuvant to enhance the immune response elicited by Newcastle disease vaccine in chickens

The present study was to evaluate the adjuvant effect of sunflower seed oil containing saponins extracted from the stem and leaf of Panax ginseng C.A. Meyer (E515-D) on the immune response induced by an inactivated Newcastle disease virus (NDV) in chickens. The results showed that E515-D promoted significantly higher serum NDV-specific HI and neutralizing antibody responses, IFN-γ and IL-4 levels, and lymphocyte proliferative responses to Con A, LPS, and NDV antigen than the conventional adjuvant Marcol 52. Different adjuvant effect between E515-D and Marcol 52 may be attributed to different genes expressed in two groups. Transcriptome analysis of splenocytes showed that there were 1198 differentially expressed genes (DEGs) with 539 up and 659 down regulated in E515-D group while 1395 DEGs with 697 up and 698 down regulated in Marcol 52 group in comparison with the control group. Analysis of gene ontology (GO) term and kyoto encyclopedia of Genes and Genomes (KEGG) pathways showed that the predominant immune related pathways included “Toll-like receptor signaling pathway”, “NOD-like receptor signaling pathway”, “C-type lectin receptor signaling pathway”, and “Phosphatidylinositol signaling system” in E515-D group while Marcol 52 were “NOD-like receptor signaling pathway”, “Phagosome”, and “Lysosome”, and the most relevant DEGs in E515-D group were STAT1, STAT2, PI3K, and IL-6. Considering the excellent adjuvant activity and vegetable origin, E515-D deserves further study as an adjuvant for vaccines used in food animals.

Evaluation for Efficacy of Commercially Available Vaccines Against Challenge with Newcastle Disease Virus Genotype VII in Broilers

The study evaluated the protective efficacy of commercially available live and inactivated Newcastle Disease Virus (NDV) vaccines. Moreover, study also highlighted the implementation of genotypically-matched NDV vaccines to the currently circulated velogenic genotype VII strain in commercial broilers vaccination regimes in Egypt. Serum antibodies level was assessed by Haemagglutination Inhibition method .Efficacy of Newcastle Disease killed and live vaccine was also determined using challenge test. Group A immunized with live attenuated and inactivated NDV vaccines genotype VII homologous to challenge virus provided non-significant protection against mortality .It proved 20 % as compared to 15 % mortalities in group B immunized with live attenuated and inactivated NDV vaccines genotype II heterologous to challenge virus. Meanwhile, group Aredult proved a significant reduction in viral shedding by cloacal swabs in compared with group B ,7 days post-challenge. Final Results of the present work concluded that live and inactivated NDV genotype VII vaccines antigenically matched to currently epidemic NDV genotype VII providing better control on virus shedding if compared with different genotype II vaccines. However, both vaccines provided good protection against likely virulent challenge in commercial broilers.

Protective efficacy of the Newcastle disease virus genotype VII–matched vaccine in commercial layers

Newcastle disease virus (NDV) is a major threat to the poultry industry worldwide, with a diversity of genotypes associated with severe economic losses in all poultry sectors. Class II genotype VII NDV are predominant in the Middle East and Asia, despite intensive vaccination programs using conventional live and inactivated NDV vaccines. In Egypt, the disease is continuously spreading, causing severe economical losses in the poultry industry. In this study; the protective efficacy of a commercial, inactivated recombinant genotype VII NDV–matched vaccine (KBNP-C4152R2L strain) against challenge with the velogenic NDV strain (Chicken/USC/Egypt/2015) was evaluated in commercial layers. Two vaccination regimes were used; live NDV genotype II (LaSota) vaccine on days 10, 18, and 120, with either the inactivated NDV genotype II regime or inactivated NDV genotype VII–matched vaccine regime on days 14, 42, and 120. The 2 regimes were challenged at the peak of egg production on week 26. Protection by the 2 regimes was evaluated after experimental infection, based on mortality rate, clinical signs, gross lesions, virus shedding, seroconversion, and egg production schedule. The results show that these 2 vaccination regimes protected commercial layer chickens against mortality, but some birds showed mild clinical signs and reduced egg production temporarily. However, the combination of live NDV genotype II and recombinant inactivated genotype VII vaccines provided better protection against virus shedding (20% and 0% vs. 60% and 40%) as assessed in tracheal swabs and (20% and 0% vs. 20% and 20%) in cloacal swabs collected at 3 and 5 D post challenge (dpc), respectively. In addition, egg production levels in birds receiving the inactivated NDV genotype VII–matched vaccine regime and in those given inactivated genotype II vaccines were 76.6, 79, 82, and 87.4% and 77.7, 72.5, 69, and 82.5% at 7, 14, 21, and 28 dpc, respectively. The results of this study indicate that recombinant genotype-matched inactivated vaccine along with a live attenuated vaccine can reduce virus shedding and improve egg production in commercial layers challenged with a velogenic genotype VII virus under field conditions. This regime may ensure a proper control strategy in layers.

Comparative safety and efficacy of two bivalent vaccines containing Newcastle disease LaSota and avian influenza H9N2 Sidrap isolate formulated with different oil adjuvants.

Background and Aim:Newcastle disease (ND) and avian influenza (AI) are two devastating diseases of poultry, which cause great economic losses to the poultry industry and disrupt food security in our country. The use of ND-AI inactive bivalent vaccine is very effective and economical to prevent and control ND and AI disease. Bivalent ND LaSota-AI H9N2 vaccine is not yet available in Indonesia. The inactivated vaccines used in poultry industry often require oil adjuvant to elicit a sufficient immune response. This study aimed to develop the bivalent inactive vaccines containing ND LaSota and AI H9N2 Sidrap isolate which are local isolates as poultry vaccine candidates, and formulated with two different commercial adjuvants, then compared.Materials and Methods:Two vaccines bivalent were prepared by emulsifying inactivated Newcastle disease virus (LaSota strain) and AI H9N2 Sidrap isolate viruses with Marcol white mineral oil and Montanide ISA70 adjuvants. Both of bivalent vaccines were tested for safety (physical and histopathological at the injection site) and efficacy in specific-pathogen-free chickens. Parameters used for the evaluation of the efficacy were immunogenicity by hemagglutination inhibition and protection percentage.Results:Both bivalent vaccines are safe to use. Post-vaccination (PV) immune response was observed using a hemagglutination inhibition test at 2, 3, 4, 5, 6, 7, and 8 weeks of PV. The bivalent vaccine B gives a better immune response to ND at 2, 3, and 4 weeks of PV (p<0.05) compared to the bivalent vaccine A, but in 5, 6, 7, and 8 weeks, the PV does not show differences in the immune response. The immune response to AI H9N2 showed differences at weeks 2 and 3 PV (p<0.05) with the bivalent vaccine B indicated higher immunity. A single immunization with both bivalent vaccines induces 100% protection in chickens that have been vaccinated against the deadly challenge with the virulent ND virus.Conclusion:Both of bivalent vaccines are safe to use and provide good efficacy against virulent ND viruses, but bivalent vaccine B (with Montanide ISA70 adjuvant) shows better immune response than bivalent vaccine A (Marcol white mineral oil adjuvant).

Inactivation of Aerosolized Newcastle Disease Virus with Non-thermal Plasma

Abstract.HighlightsNon-thermal plasma treatment completely inactivated Newcastle disease virus (NDV).Higher airborne virus concentrations at lower humidity levels &amp;amp; higher flow rates.Nebulization (20 min) did not inactivate NDV .Abstract.The airborne transmission of poultry viruses, such as Newcastle disease virus, is major health and economic concern. The poultry industry currently lacks a cost-effective solution to prevent airborne transmission. The present study explored non-thermal plasma’s ability to inactivate poultry viruses, by challenging a laboratory-scale non-thermal plasma reactor with aerosolized Newcastle disease virus at increasing flow rates (i.e., decreased direct treatment time). Viruses were inactivated below the green fluorescent protein (GFP) focus-forming units per mL (GFU/mL) limit of detection at the flow rates 18, 23, and 28 liters per minute (LPM). However, this study did not differentiate between inactivation effects caused by direct NTP treatment and indirect NTP treatment (viruses exposed to ozone after collection on gelatin membrane filters). A strong relationship (R2 =.99) was observed between decreasing relative humidity and increasing airborne virus concentrations. Twenty minutes of nebulization did not significantly change liquid virus concentration in the nebulizer. Keywords: Aerosol, Airborne, Newcastle disease, Non-thermal, Pathogen, Plasma, Virus.

Process development for quantitation and vaccine efficacy assessment of recombinant hemagglutinin-neuraminidase

Recombinant hemagglutinin-neuraminidase (HN) based subunit vaccine, which is non-infectious and can be produced using insect cell-culture systems, is a potential alternative to conventional live and inactivated Newcastle disease virus (NDV) vaccines. However, process development for manufacture and efficacy assessment of HN subunit vaccines has been hampered by the absence of reference standards, a cornerstone for robust and sensitive quantitative analytical methods. In this work, a downstream purification strategy was developed to obtain NDV HN which was expressed with a hexa-histidine fusion tag (rHN) to facilitate detection using generic antibodies. Highly purified rHN (∼95%) attained after detergent extraction and two-stage ion-exchange-hydroxyapatite column chromatography was subsequently utilized as reference standards for quantitative ELISA development. Recovery of rHN at different stages of purification was monitored. Quantitation of rHN from crude cell lysates was performed for dose-ranging antibody response and protective efficacy studies. A higher dose (1500 ng) of rHN was correlated to a significant reduction in virus shedding and attainment of herd immunity, as indicated by a higher proportion of chickens (92%) with hemagglutination inhibition (HI) antibody titers ≥ log23. The outcome of this study, shows the importance of downstream process development in enabling robust quantitation and efficacy assessment of a recombinant subunit vaccine.

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.

The efficacy of binary ethylenimine-inactivated vaccines of Gianyar-1/AK/2014 virulent strain in protecting chickens against Tabanan-1/ARP/2017 virulent Newcastle disease virus isolates.

Aim:This study aimed to prepare binary ethylenimine (BEI)-inactivated virulent Newcastle disease virus (NDV) vaccine and to examine their ability to induce a protective antibody response in commercial chickens.Materials and Methods:A virulent NDV field isolate Gianyar-1/AK/2014 was propagated in chicken-embryonated eggs and was then inactivated with BEI at a concentration of 4 mM. Three groups of chickens with low-level (2 log2 hemagglutination inhibition [HI] units) maternally derived antibodies against NDV were then immunized with the BEI-inactivated vaccine. A commercial live vaccine (LaSota strain) was used as positive control, and phosphate-buffered saline (PBS) was used as negative control. A challenge experiment with a virulent NDV of Tabanan-1/ARP/2017 was performed at 3 weeks post-vaccination.Results:At 2 weeks post-immunization, the mean titers of antibodies against NDV in serum samples of chickens immunized with 0.2 mL of BEI-inactivated NDV (Group I), with live commercial NDV vaccine (Group II) and with PBS (Group III) were 3±0.94 log2 HI units, 4.9±0.99 log2 HI unit, and 0.0±0.0 HI units, respectively. At week 3 post-immunization, the mean titers of the antibodies for the three groups were 5±1.09 log2 HI units, 6.9±0.32 log2 HI units, and 0.00 HI units, respectively. The antibody titer induced by inactivated NDV Gianyar-1/AK/2014 isolates examined at 2 and 3 weeks post-vaccination was still at a significantly (p<0.01) lower level as compared to those induced by commercial life vaccine. However, the challenge test with virulent NDV of Tabanan 1/ARP/2017 isolates showed that all immunized chickens (Group I and II) survived without exhibiting any clinical sign post-challenge with the protection rates of 100%, whereas all chickens injected with PBS (Group III) died with clinical signs of ND.Conclusion:This finding shows that the BEI-inactivated vaccines prepared using virulent NDV of Gianyar-1/AK/2014 strain was able to induce protective antibody response in chickens but still at a lower level than those induce by commercial live NDV vaccine.

Comparative efficacy of commercial inactivated Newcastle disease virus vaccines against Newcastle disease virus genotype VII in broiler chickens

Newcastle disease is still causing huge economic losses and devastating outbreaks in poultry flocks despite implementation of extensive vaccination programs. Five commercial broiler chicken groups were established as G1 (non-vaccinated, non-challenged group) and G2 (non-vaccinated, challenged group), and 3 vaccinated challenged groups as G3 (vaccinated with heterologous inactivated Newcastle disease virus (NDV) genotype II (NDV II) vaccine), G4 (vaccinated with homologous inactivated NDV genotype VII (NDV VII) vaccine), and G5 (vaccinated with bivalent (heterologous inactivated NDV II plus H5) vaccine) were used. Challenge test was done using a velogenic NDV genotype VII (vNDV VII) at 28-d olds. Respiratory signs, greenish diarrhea, and obvious post-mortem lesions of vNDV VII appeared in all the challenged birds whether vaccinated or not. In addition, the mortality rate decreased from 93.3% in G2 to 46.7%, 53.3%, and 66.7% in G4, G5, and G3, respectively. Overall, 2 wk postchallenge; body weight loss (%) had increased mainly in G2, with some improvement in chickens in G4 followed by G5 and chickens of G3 showed the least improvement. At 28 d (day of challenge), the highest hemagglutination inhibition values were 4.3 and 5.4 log2 in chickens in G4 and G5, respectively, which increased in all groups after the challenge. Cytokine (IL-6 and IFN-γ) levels were significantly higher (P < 0.05) in the vaccinated groups than that in the non-vaccinated group, especially in G5. Viral shedding in the trachea was higher than that in the cloacal swabs in all vaccinated and non-vaccinated challenged groups with peak shedding on the 6th day post challenge for both swabs, and the lowest viral shedding titers were observed in chickens in G5. Therefore, the use of homologous genotype NDV with inactivated vaccine conferred a higher clinical protection in terms of body weight loss and mortality against vNDV VII challenge in broiler chickens; however, the heterologous vaccine used in G5 induced the highest cell-mediated immune response and hemagglutination inhibition titers with the lowest viral shedding titer.

Truncated chicken MDA5 enhances the immune response to inactivated NDV vaccine

Melanoma Differentiation-Associated protein 5 (MDA5) is a cytoplasmic sensor for viral invasion and plays an important role in regulation of the immune response against Newcastle disease virus (NDV) in chickens. MDA5 was used as an adjuvant to enhance the humoral immune response against influenza virus. In the current study, truncated chicken MDA5 [1–483 aa, chMDA5(483aa)] expressed by recombinant adenovirus was administered to specific-pathogen-free (SPF) chickens to improve the immune response induced by inactivated NDV vaccine. A total of 156 SPF chickens were divided into six groups, and after two rounds of immunization, the humoral immune response, cell-mediated immune (CMI) response and the protective efficacy of the vaccines against NDV challenge were evaluated. The results showed that co-administration of chMDA5(483aa) expressed by adenovirus increased the NDV-specific antibody response by 1.7 times and chickens received chMDA5(483aa) also gained a higher level of CMI response. Consistently, the protective efficacy of the inactivated NDV vaccine against virulent NDV (vNDV) challenge was improved by co-administrate with chMDA5(483aa), as indicated by the reduced morbidity and pathological lesions, lower levels of viral load in organs and reduced virus shedding. Our study demonstrated that chMDA5(433aa) expressed by adenovirus could enhance the immune efficacy of inactivated NDV vaccine in chickens and could be a potential adjuvant candidate in developing chicken NDV vaccines.

Assessment of in vitro potency of inactivated Newcastle disease oil-adjuvanted vaccines using hemagglutination test and blocking ELISA.

Aim:The present study was aimed to establish a protocol for the evaluation of the in vitro potency of commercial inactivated Newcastle disease virus (NDV) oil-adjuvanted vaccines using hemagglutination test (HA) and blocking ELISA (B-ELISA) based on polyclonal antibodies.Materials and Methods:Aqueous phases from a total of 47 batches of inactivated NDV vaccines manufactured by 20 different companies were extracted with isopropyl myristate. The viral antigen in each sample was detected and quantified by a standard HA test and a B-ELISA assay. To verify the efficiency of the antigen extraction method used in the batches which showed HA and to test the validity of using in vitro antigen quantification by HA and B-ELISA tests, a subset of 13 batches (selected from the total 47 batches) was inoculated in groups of 3-4-week-old specific pathogen-free chickens using the recommended vaccine dose. The immunogenicity of the selected vaccine batches was assessed by the NDV-hemagglutination inhibition antibody titers in individual serum samples collected 4 weeks after vaccination. Further, the efficacy of the vaccines and their protection rates were determined by a challenge test carried out for the vaccinated chickens with the Egyptian 2012 isolate of the virulent NDV genotype VII.Results:A strong correlation was observed between HA titers and B-ELISA mean titers in the tested 47 batches (R2=0.817). This indicated the possibility of using the latter in vitro assays for vaccine potency assessment. The recommended protective NDV antigen titer measured by B-ELISA was determined to be 28 ELISA units per dose. The comparison between the HA titers of the aqueous extracts of test vaccines and the corresponding results of in vivo potency assays (i.e., immunogenicity and efficacy), including antibody titers in the serum of vaccinated birds, indicated that the efficiency of the antigen extraction used may interfere with obtaining a strong correlation between the in vitro and in vivo results.Conclusion:HA or B-ELISA tests can be used as rapid and cost-effective alternatives to traditional in vivo potency tests for vaccine potency assessment by quantifying the NDV antigen present in aqueous phase extracts of the tested vaccines. The latter in vitro protocol, however, requires efficient extraction of the antigen to be able to obtain good correlation with the traditional in vivo potency tests.

Comparison of the immune response between local manufactured and commercial inactivated Newcastle Disease Virus vaccine in a challenge trail with field isolated Newcastle Disease Virus

Comparison of the immune response between local manufactured and commercial inactivated Newcastle Disease Virus vaccine in a challenge trail with field isolated Newcastle Disease Virus

Comparison of the immune response between local manufactured and commercial inactivated Newcastle Disease Virus vaccine in a challenge trail with field isolated Newcastle Disease Virus

Velogenic Newcastle Disease Virus was isolated from broiler chickens in Northern Iraq. An inactivated vaccine was manufactured locally using as seed virus ELD50/ml109 and then compared with commercial inactivated vaccine in an experimental study which included 120 broiler chicks divided into three groups (G1 unvaccinated control, G2 for commercial vaccine and G3 for local vaccine). The chicks were injected subcutaneously at 3 days old followed by booster Lasota live vaccine eye drop. Indirect ELISA technique was used to estimate the antibody titer from the collected sera of chicks at age 7, 17 and 27 days (pre-challenge) and challenged at 31 days old with the same virus. The results indicated that there were significant differences (P&lt;0.05) between vaccinated group G2 and G3 at 27th day old and showed a high antibody level with high protection percentage compared with the control. G1 which shown no survival, 100% mortality and severe histopathological lesions, while in G2 and G3 was 43% and 87% respectively. Post-challenge antibody titers of survival chicks showed in G3 significantly over the G2 with less severe histopathological lesions. This study concluded that vaccine failure could occur due to factors of the immune status of the host, improper storage of vaccine, improper vaccination and variant pathogenic virus strain. More epidemiological surveillances are required to decide the actual impact of the disease in poultry farms and matching the vaccines.

Prime-boost vaccination strategy against avian influenza and Newcastle disease viruses reduces shedding of the challenge viruses.

In the present study, we carried-out assessment of efficacy of different immunization strategies using two bivalent vaccine formulations containing antigens of inactivated Newcastle disease virus (NDV-genotype VIId) and reassortant highly pathogenic avian influenza virus (H5N1-HPAIV) mixed with Montanide ISA71 and Montanide Gel02 as adjuvants. The efficacy of the prepared vaccines was evaluated by determining the cellular and humoral immune responses. In addition, protection against H5N1-AIV and NDV-genotype VIId challenge viruses post vaccination was assessed when Montanide-Gel02 based vaccine was inoculated in 10-days-old specific pathogen free chicks intraocularly once, twice or once followed by a boost with the Montanide ISA71 based vaccine. The cytokines profile analysis demonstrated that the prime-boost strategy induced the highest up-regulation in interferon-gamma (11.39-fold change) and interleukin-6 (14.12-fold change) genes expression. Also, enhanced lymphocytes proliferation was recorded beside increased antibody titers with protection levels reaching 50 and 60% against H5N1 and NDV challenge; respectively. Immunization with Montanide ISA71 inactivated vaccine induced 80% protection; however, the prime-boost combination afforded complete protection (100%) in the challenged chickens against mortality, clinical signs and virus shedding. Finally, these results highlight the significance of considering not only different vaccine platforms but also vaccination strategies to maximize protection against AIV and NDV with regards to the longevity of the vaccine-induced immune response.

Evaluation of Locally Prepared Inactivated Newcastle Disease Virus Vaccine

Vaccination is one of the control measures of the disturbing Newcastle Disease in Egypt. InactivatedNewcastle Disease virus (NDV) vaccine was prepared using a local isolate (NDV-ch-EG-CLEVBF604-2016), from Qaliobia governorate, Egypt, with Montanide ISA70VG as an oil adjuvant. Theprepared vaccine was evaluated in comparison with an inactivated imported vaccine. Chick andTurkey chick groups vaccinated with either prepared or imported vaccines showed high serumantibody titers from the 3rd week post vaccination and reached the highest titer at the 9th week postvaccination using HI test. Both prepared and imported vaccines gave near percentage of protectionagainst the local and the classical strain in both groups of chicks and turkeys ,21 days postvaccination, with no clinical signs or lesions on examination. Concluding that the locally preparedinactivated NDV vaccine can protect chicken and turkey against both homologous and heterologouschallenging viruses.

Resiquimod enhances mucosal and systemic immunity against avian infectious bronchitis virus vaccine in the chicken

Adjuvant enhancing mucosal immune response is preferred in controlling many pathogens at the portal of entry. Earlier, we reported that a toll-like-receptor 7 (TLR7) agonist, resiquimod (R-848), stimulated the systemic immunity when adjuvanted with the inactivated Newcastle disease virus vaccine in the chicken. Here, we report the effect of R-848 when adjuvanted with live or inactivated avian infectious bronchitis virus (IBV) vaccines with special emphasis on mucosal immunity. Specific pathogen free (SPF) chicks (n = 60) were equally divided into six groups at two weeks of age and immunized with either inactivated or live IBV vaccine adjuvanted with or without R-848. Groups that received either PBS or R-848 served as control. A booster was given on 14 days post-immunization (dpi). R-848 enhanced the antigen specific humoral and cellular immune responses when co-administered with the vaccines as evidenced by an increase in the antibody titre in ELISA and stimulation index in lymphocyte transformation test (LTT) till 35 dpi and increased proportion of CD4+ and CD8+ T cells on 21 dpi in the flow cytometry. Interestingly, it potentiated the IgA responses in the tear and intestinal secretions when used with both live and inactivated IBV vaccines. The combination of IBV vaccine with R-848 significantly up-regulated the transforming growth factor beta 4 (TGFβ4) transcripts in the peripheral blood mononuclear cells (PBMCs) than that of the respective vaccine per se. An enhanced secretory IgA response is likely due to the up-regulation of TGFβ4, which is responsible for class switching to IgA. In conclusion, co-administration of R-848 with inactivated or live IBV vaccine enhanced the systemic as well as mucosal immune responses in the chicken.

Intranasal administration of inactivated avian influenza virus of H5N1 subtype vaccine-induced systemic immune response in chicken and mice.

Aim:The need for non-parenteral administration of inactivated avian influenza virus of H5N1 subtype (AIV-H5N1) vaccine is paramount. Here, we provide preliminary data on the immune response of chicken and mice after intranasal administration of AIV-H5N1-inactivated vaccine with ISCOMS, Inmunair (INM), and combined ISCOMS and INM as an adjuvant.Materials and Methods:The AIV isolate of A/Chicken/Denpasar/01/2004 (H5N1) was cultivated in specific pathogen-free chicken eggs and inactivated with formaldehyde. The vaccine preparation was added with those adjuvants for intranasal administration and aluminum hydroxide for subcutaneous injection. The chicken and mouse were vaccinated at the age of 3 weeks or 1 month and repeated 2 weeks thereafter. In one experiment, chicken was injected with Newcastle disease virus (NDV) at the same time with AIV vaccine. The sera were collected at one (serum 1) and 2 w (serum 2) after booster vaccination. The anti-AIV-H5 and NDV antibodies in chicken sera were detected using hemagglutination inhibition (HI) assay. Mouse IgG anti-AIV-H5N1 antibody was detected using ELISA.Results:The result shows that the geometric mean titers (GMTs) of chicken sera of intranasal vaccinated with inactivated AIV-H5N1 vaccine with mixed ISCOM- INM as adjuvant were <20.0 and 22.7 unit HI-unit (HIU) in serum 1 and serum 2, respectively. The GMTs of the positive control group were 23.7 and 25.7 HIU in serum 1 and serum 2, respectively. The result of the second experiment shows that IgG anti-AIV-H5N1 was detected in mouse sera. In the third experiment, the GMTs of anti-NDV in chicken vaccinated subsequently with inactivated NDV vaccine and AIV-H5N1 with mixed ISCOMS-INM administrated intranasally and aluminum hydroxide adjuvant administrated through subcutaneous injection as well as positive control group receiving NDV vaccine only were 28.0, 28.0, and 27.4 HIU in serum 1 while were 29.6, 29.2, and 28.2 HIU in serum 2, respectively.Conclusion:Intranasal administration of inactivated AIV-H5N1 vaccine-induced a systemic immune response in chicken and mice after adding ISCOMS and/or INM as adjuvants. The adjuvant and the intranasal administration caused no immunosuppressive effect on the chicken immune response to NDV vaccine.