Oil Adjuvant Vaccine Research Articles

Immune responses induced by oil-adjuvanted inactivated vaccine against Flavobacterium psychrophilum in ayu Plecoglossus altivelis

Oil-adjuvant formulated formalin killed cells of Flavobacterium psychrophilum (FKC + Adj) is strongly effective against bacterial cold-water disease (BCWD) in ayu Plecoglossus altivelis. In this study, we aimed to understand mechanisms underlying the strong protection by the vaccine in ayu. Antibody titer of FKC + Adj and formalin-killed cells (FKC) group was significantly higher than those of modified cytophaga broth injected (MCY) group and MCY with the adjuvant (MCY + Adj) group. The highest antibody titer was observed in FKC + Adj group. Granulomatous inflammation without lymphocyte cuff was observed in the spleen and trunk kidney of FKC + Adj and MCY + Adj group, while the size of the granuloma was bigger in FKC + Adj than in MCY + Adj group. Gene expression level for IL-8 was significantly up-regulated in FKC + Adj group at 4 weeks after the vaccination. In contrast, IL-10 gene expression level was significantly suppressed in FKC + Adj at 4 weeks after the vaccination. F. psychrophilum was almost cleared in the spleen and trunk kidney of FKC + Adj group within 2 days after the challenge. Fluorescent immunohistochemistry showed that a lot of bacterial signals were detected in the spleen and trunk kidney of challenged fish in MCY, FKC and MCY + Adj group. However, the fluorescent signal was not detected in the organs of FKC + Adj group after the challenge. These data suggest that F. psychrophilum is immediately cleared in FKC + Adj vaccinated fish and both specific antibody and activation of phagocytes are essential to clear F. psychrophilum in ayu.

Immunogenicity of imported foot-and-mouth vaccines in different species in Mongolia

Foot-and-mouth disease (FMD) is a high impact viral disease of livestock for which vaccines are extensively used in control. Mongolia has regular incursions of FMD virus that are typically limited to the eastern region although large epidemics are occasionally reported in the normally disease-free western areas. Vaccines are imported and form an important component of the control strategy. In 2015, post-vaccination monitoring guidelines were published by the FAO-OIE recommending approaches for assessing the appropriateness of imported vaccines including small-scale immunogenicity studies. This study used these recommended approaches to guide the use of vaccine adjuvant type and the need for a one or two dose primary course in the national control programme considering cattle, sheep and Bactrian camels and also whether these vaccines were appropriate for the FMD virus lineages considered high risk to Mongolia (A/ASIA/Sea-97; O/SEA/Mya-98; O/ME-SA/PanAsia; O/ME-SA/Ind-2001). The results of these immunogenicity studies indicated that in cattle and sheep, oil-adjuvanted vaccines led to higher and more persistent neutralisation titres that were satisfactory against the target lineages if a two-dose primary course was utilised. In contrast, aqueous-adjuvanted vaccines were associated with lower titres that likely required a booster after 3 months. Levels of antibodies in Bactrian camels were significantly lower although it is unknown how these may correlate with protection under experimental or field exposure conditions. The results of this study have implications for vaccine policy in Mongolia and suggest further studies on the role of Bactrian camels in the epidemiology of FMD are necessary to indicate if further research on FMD vaccines are needed in this species.

Efficacy of inactivated velogenic Newcastle disease virus genotype VII vaccine in broiler chickens.

Newcastle disease (ND) causes severe economic losses in poultry production. Despite the intensive vaccination regimes of NDV in Egypt, many outbreaks are being reported. The present study focused on the preparation and evaluation of inactivated velogenic Newcastle disease virus vaccine (genotype VII) isolated from Egyptian broiler chicken during 2015-2016. Fifty-five tissue samples including trachea, lung, liver, proventriculus, intestine, and kidney collected from commercial broiler chickens were used for virus isolation in specific pathogen-free embryonated chicken eggs (ECE) and identified using RT-PCR and sequencing. The isolates were classified by sequencing as velogenic NDV genotype VIId containing F0 protein cleavage site motifs (112RRQKRF117). A selected isolate was served as a master seed for the preparation of inactivated NDV vaccine with or without Montanide ISA70 adjuvant and evaluated in SPF chicks. Nine NDV isolates were isolated on ECE and the highest infectivity titer of the virus was 7.50 log10 EID50 mL-1 by the 5th passage. Vaccinated chicks with NDV-Montanide ISA70 adjuvanted vaccine exhibited antibody titer of 5.20 log2 at the 3rd-week-post-vaccination (WPV) with the highest titer (8.90 log2 mL-1) at the 6th-WPV. Protective antibodies values were persisted to 12th WPV followed by a gradual decrease to the end of the experiment (16th weeks). Vaccination of chicks with inactivated NDV isolate without adjuvant failed to induce protective HI antibodies all over the experiment. Chickens vaccinated with the ISA70 adjuvant vaccine were passed homologous challenge tests with 100% protective efficiency, while the unadjuvanted vaccine could not provide any protective efficiency. In conclusion, the preparation of inactivated oil adjuvant vaccine from NDV field circulating strains was efficient in controlling the disease in Egypt.

Improved immune responses and safety of foot-and-mouth disease vaccine containing immunostimulating components in pigs.

BackgroundThe quality of a vaccine depends strongly on the effects of the adjuvants applied simultaneously with the antigen in the vaccine. The adjuvants enhance the protective effect of the vaccine against a viral challenge. Conversely, oil-type adjuvants leave oil residue inside the bodies of the injected animals that can produce a local reaction in the muscle. The long-term immunogenicity of mice after vaccination was examined. ISA206 or ISA15 oil adjuvants maintained the best immunity, protective capability, and safety among the oil adjuvants in the experimental group.ObjectivesThis study screened the adjuvant composites aimed at enhancing foot-and-mouth disease (FMD) immunity. The C-type lectin or toll-like receptor (TLR) agonist showed the most improved protection rate.MethodsExperimental vaccines were fabricated by mixing various known oil adjuvants and composites that can act as immunogenic adjuvants (gel, saponin, and other components) and examined the enhancement effect on the vaccine.ResultsThe water in oil (W/O) and water in oil in water (W/O/W) adjuvants showed better immune effects than the oil in water (O/W) adjuvants, which have a small volume of oil component. The W/O type left the largest amount of oil residue, followed by W/O/W and O/W types. In the mouse model, intramuscular inoculation showed a better protection rate than subcutaneous inoculation. Moreover, the protective effect was particularly weak in the case of inoculation in fatty tissue. The initial immune reaction and persistence of long-term immunity were also confirmed in an immune reaction on pigs.ConclusionsThe new experimental vaccine with immunostimulants produces improved immune responses and safety in pigs than general oil-adjuvanted vaccines.

Phoenix dactylifera, mentha piperita and montanide™ ISA-201 as immunological adjuvants in a chicken model

This study evaluated plant-based immune-adjuvants from crude extracts of Phoenix dactylifera and Mentha piperita as promising adjuvants for vaccines because of the limited side effects associated with plant extracts. In addition, Montanide™ ISA 201 previously used in vaccines in cattle. Eight different infectious coryza (IC) vaccines were prepared from three serovars [A (W strain and local strain), C (Modesto strain) and B (0222 strain)] with eight Avibacterium paragallinarum vaccines adjuvants formulae using liquid paraffin, Montanide™ ISA 71, Montanide™ ISA 201, and Montanide™ Gel adjuvants, P. dactylifera and M. piperita as immune-stimulants at a concentration of 1 mg and 2 mg incorporated with or without liquid paraffin oil as an adjuvant. These vaccines were applied in a chicken model. After a single immunization, the eight vaccine formulations were evaluated using the ELISA and Microplate agglutination test. Evidence of protection in the immunized birds was based on the results after challenge and bacterial isolation. The incorporation of the crude aqueous extract of P. dactylifera or M. piperita at a concentration of 2 mg in a liquid paraffin oil adjuvanted IC vaccine could be employed as an efficient adjuvant for chicken to IC vaccine to enhance immune responses. Also,Montanide™ ISA 201 may be the best adjuvant to be used to enhance the protective response against Av. paragallinarum. Our results confirm that aqueous extracts of M. piperita leaves and P. dactylifera fruit have immunomodulatory potentials in vivo and elevated serum antibodies against Av. Paragallinarum.

Immune cells transferred by colostrum do not influence the immune responses to foot-and-mouth disease primary vaccination

Little is known about the influence of maternal antibodies and immune cells transferred through colostrum on the immune responses of calves to the currently used foot-and-mouth disease (FMD) vaccines. Here we evaluated the humoral and cellular immune responses induced by vaccination of colostrum-deprived calves and calves that received equivalent amounts of colostrum preparations that differed in the presence or absence of maternal immune cells but contained the same quantity and quality of anti-foot-and-mouth disease virus (FMDV) antibodies. Three groups of 32-d-old calves (n = 3 per group) were deprived of colostrum and fed either whole immune colostrum or a cell-free colostrum preparation containing only anti-FMDV antibodies. All groups were immunized with 1 dose of an oil-adjuvanted commercial vaccine. Blood samples were collected periodically before vaccination and weekly after vaccination. Immune responses specific to FMDV were assessed based on T-cell proliferation, IFN-γ production, total and neutralizing serum antibodies, and isotype profile. All vaccinated calves developed IFN-γ and lymphoproliferative responses, irrespective of the colostrum received. Colostrum-deprived animals responded to vaccination with a primary IgM response followed by an increase of IgG1 titers. Conversely, antibody titers decreased in all colostrum-fed calves after vaccination. This study demonstrates for the first time that maternal immune cells transferred to the calves through colostrum do not modify immune responses to FMD vaccine, and it confirms the interference of maternal antibodies in the induction of humoral but not cell-mediated immune responses.

Enhancement of Immunogenicity and Protective Efficacy against Bovine Respiratory Disease Viruses (BVD, BoHV1, PI3, and BRS) Vaccine.

A highly potent pneumo-4 vaccine of combined inactivated Bovine Viral Diarrhea Virus, Infectious Bovine Rhinotracitis Virus, Parainfluenza-3 Virus and Bovine Respiratory Syncytial Virus could play a valuable role in respiratory disease control program in calves. In this study we determined the influence of virus concentration by polyethylene glycol (PEG) precipitation, and the use of montanide oil & gel as adjuvants on the immune response of calves to the inactivated Pneumo-4 vaccine. Two batches of concentrated viruses’ vaccine were prepared, one adjuvanted with aluminum hydroxide gel and the other adjuvanted with oil. Both batches administered twice to six-month-old seronegative calves through intramuscular (IM) route. Different doses, 2ml, 2.5ml, and 3ml of the concentrated gel adjuvanted & 2.5ml,3ml and 3.5ml of concentrated oil vaccine were tested compared with 5ml for the commercial un-concentrated Pneumo-4 vaccine. The induced BVDV, IBRV, PI-3V and BRSV antibodies were followed up in the sera of vaccinated calves up to12M post vaccination (M.P.V.) using Serum Neutralization Test (SNT). The result revealed that concentration of viruses by PEG improve the quality of antigen used in the vaccine formulation to produce a good quality combined inactivated vaccine. Also, both concentrated adjuvanted vaccines gave a significant effect on all vaccinated animals but the oil adjuvanted vaccine was particularly better and effective than gel adjuvanted where oil adjuvanted vaccine induced early protective immune response and showed prolongation of antibody secretion in comparison to the Aluminum Hydroxide gel.

Optimisation and comparison of different methods for antigen extraction from oil adjuvant inactivated infectious bursal disease vaccine

Antigenic quantification based in vitro method for potency estimation of oil adjuvant inactivated vaccine requires a suitable antigen exaction protocol for maximum recovery of antigen from the vaccine. To find out the suitable protocol, in the present study, seven different organic solvents including isopropyl Myristate (IPM), isopropyl Palmitate (IPP), benzyl alcohol, butanol, acetone, chloroform/methanol and dimethyl sulphoxide (DMSO) were tested to recover the antigen from the six oil adjuvant inactivated infectious bursal disease (IBD) and two Newcastle disease (NDV) vaccines from different manufacturers. The mean OD450 values of antigen extracted from all the vaccines using different organic solvents were determined by in house developed sandwich ELISA (sELISA). The mean average ODs of all six IBD vaccines were 2.794, 2.520, 2.690 and 2.359, respectively from IPM, IPP, benzyl alcohol and butanol methods. Antigen recovered by acetone, chloroform/methanol and DMSO methods gave ODs value of 0.019, 0.203 and 0.062, respectively. Based on the sELISA results, IPM and IPP methods were found as most appropriate for antigen extraction from oil adjuvant IBD vaccine. The antigen recovery was further confirmed by protein estimation of antigen recovered by IPM and IPP. The results of the present study indicated that IPM and IPP were the two appropriate organic solvents for antigen extraction from oil adjuvant IBD vaccine.

Immunomodulatory Effect of Purified Exotoxins of <i>Staphylococcus aureus</i> in Association with Bird Flu Virus Vaccine in Broilers

Immunization is the most effective method still used against infectious agents. Although not always, vaccines ineffectiveness is reported enormously against many of the pathogens throughout the world in poultry, particularly in case of killed or sub unit vaccine. The current project is, therefore, carried out as a preliminary study on broiler chickens to investigate the modulation of immune system against avian influenza virus in association with purified Staphylococcus aureus toxoid. After isolation of Gram positive cocci bacteria on mannitol salt agar from raw milk, yogurt and chicken meat were subsequently biochemically characterized by using rapid diagnostic kit. Pure culture of S. aureus was inoculated into digitally controlled bio-fermentor containing mannitol salt broth for production of toxins. Enormous production of bacteria was passed through sequence of filtration system based on 0.45 μm followed by 0.22 μm size. The centrifugation of the filtrate was made at 10,000 rpm for 60 minutes at 5℃ followed by 56,100 rpm for 20 minutes and clear supernatant containing Staphylococcus enterotoxin (SEs) was obtained. Bradford estimation of proteins further provided 305 μg/ml of SEs toxoid. Four types of oil adjuvant avian influenza type H9N2 virus vaccines (without toxoid, 91.5 μg/0.3ml, 22.8 μg/0.3ml and 11.43 μg/0.3ml) were injected into healthy AI H9N2 susceptible broilers and anti-H9N2 HI antibody titers were measured in terms of hemagglutination inhibition test. It was observed that on the 8th day, post vaccination cumulative mean anti AIH9 HI antibody titer of G-1, G-2, G-3, G-4 and G-5 was 3.13 ± 0.406, 5.13 ± 0.246, 3.96 ± 0.159, 3.25 ± 0.237 and 0.78 ± 0.467 respectively. It was found that all the vaccines induced protective titers 18 days’ post vaccination, but vaccine containing 91.5 μg/dose of SEs toxoid showed significantly higher (P , particularly in inactivated vaccines, could be the better choice for modulation of immediate and better immune response in future vaccines technologies.

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.

Experimental induction of mouthrot in Atlantic salmon smolts using Tenacibaculum maritimum from Western Canada.

Mouthrot, or bacterial stomatitis, is a disease which mainly affects farmed Atlantic salmon, (Salmo salar, L.), smolts recently transferred into salt water in both British Columbia (BC), Canada, and Washington State, USA. It is a significant fish welfare issue which results in economic losses due to mortality and antibiotic treatments. The associated pathogen is Tenacibaculum maritimum, a bacterium which causes significant losses in many species of farmed fish worldwide. This bacterium has not been proven to be the causative agent of mouthrot in BC despite being isolated from affected Atlantic salmon. In this study, challenge experiments were performed to determine whether mouthrot could be induced with T.maritimum isolates collected from outbreaks in Western Canada and to attempt to develop a bath challenge model. A secondary objective was to use this model to test inactivated whole-cell vaccines for T.maritimum in Atlantic salmon smolts. This study shows that T.maritimum is the causative agent of mouthrot and that the bacteria can readily transfer horizontally within the population. Although the whole-cell oil-adjuvanted vaccines produced an antibody response that was partially cross-reactive with several of the T.maritimum isolates, the vaccines did not protect the fish under the study's conditions.

Selection of Avibacterium paragallinarum Page serovar B strains for an infectious coryza vaccine

Infectious coryza is an important respiratory disease of chickens around the world and is caused by Avibacterium paragallinarum. Among the three Page serovars currently recognized for this bacterium, serovar B is a major circulating serovar in China nowadays. The cross-protection ability of the Page serovar B reference strain (0222) and five local isolates was evaluated by a vaccination-challenge trial in SPF chickens. The clinical signs seen in control birds challenged by strain 0222 and isolate HB 01 were significantly different, with isolate HB 01 giving more severe clinical signs. In terms of cross-protection, the protection in the groups vaccinated with isolate HB 01 and BJ 02 was significantly higher than that in the groups vaccinated with 0222 and the other three isolates. In addition, an experimental oil adjuvant trivalent vaccine, containing field isolate HB 01 antigen, was compared for immune efficacy with two commercial trivalent infectious coryza vaccines containing internationally recognized serovar B strains. The experimental oil adjuvant trivalent vaccine elicited best protection (80%) among the three trivalent vaccines. In conclusion, the oil adjuvant vaccine, containing field isolate HB 01 may be a better choice in control of current serovar B Av. paragallinarum outbreaks in China under current circumstances.

Immunogenicity and protective capacity of EF-Tu and FtsZ of Streptococcus suis serotype 2 against lethal infection

Vaccine development efforts against Streptococcus suis serotype 2 (S. suis 2) are often constrained by strain/serotype antigen variability. Bioinformatics analyses revealed two highly conserved S. suis 2 factors, EF-Tu and FtsZ. Murine immunization with recombinant proteins emulsified in white oil adjuvant or eukaryotic DNA vaccine vectors provided significant protection against lethal S. suis 2 challenge. Immune responses elicited by recombinant protein immunization revealed the robust generation of humoral immune responses, with a mixed induction of Th1-type and Th2-type responses. Furthermore, the antiserum from mice immunized with recombinant proteins significantly inhibited the growth of S. suis 2 in healthy pig whole blood, suggesting the triggering of a strong opsonizing response. Histological examination found that immunizing mice with purified recombinant proteins reduced neutrophil and macrophage accumulation in brain and lung tissues after challenge with virulent S. suis. Taken together, these findings reveal that EF-Tu and FtsZ may be promising targets for subunit and DNA vaccine candidates against S. suis 2 infection.

Comparison of two ELISA methods for detection of antibodies against Footand- Mouth Disease virus of cattle breeds in Turkey

The study was conducted using two ELISA methods - the liquid phase blocking ELISA (LPBE) and solid phase competition ELISA (SPCE) for the detection of foot-and-mouth disease virus (FMDV) serotype A- and O-specific antibodies of different cattle breeds in Turkey. These methods were compared in 426 cattle previously vaccinated with oil-adjuvanted bivalent vaccine as well as in sera from 40 cattle with no history of foot-and-mouth disease infection or vaccination. The results were found that SPCE had a better specificity (serotype A; 100% and serotype O; 97.50%) than LPBE (serotype A 95.00% and serotype O 92.50%). Sensitivity of SPCE had also better values (serotype A; 99.30% and serotype O; 98.59%) than LPBE (serotype A; 97.89% and serotype O; 96.48%). The results of the present study showed that the SPCE method is more reliable than LPBE.

A Combination Vaccine against Encephalomyocarditis Virus and Porcine Circovirus Type 2 Induces Protective Immune Response in Pigs

Encephalomyocarditis virus (EMCV) and porcine circovirus type 2 (PCV2) are common causative agents with high infection rate in pig farms, thus a combined vaccine against both EMCV and PCV2 is highly desirable. In the present study, we developed an oil-adjuvant combination vaccine candidate comprising of inactivated EMCV and PCV2, and evaluated the safety and immunogenicity in mice and swine. The combination vaccine was found to elicit serum antibodies and had strong neutralization activity, more importantly, passive immunization with the combined vaccine protected swine against either EMCV or PCV2 lethal infections, whereas the monovalent vaccine only prevent the one of two virus challenge. Our results demonstrated the combined vaccine was safe and induced protective immune response in mice and swine as evident from sero-conservation as well as challenge studies in swine, indicating that component vaccines did not interfere with the immunogenicity of each other.

Efficacy and safety of a non-mineral oil adjuvanted injectable vaccine for the protection of Atlantic salmon (Salmo salar L.) against Flavobacterium psychrophilum

Flavobacterium psychrophilum is the causative agent of Rainbow Trout Fry Syndrome which has had a major impact on global salmonid aquaculture. Recent outbreaks in Atlantic salmon in Scotland and Chile have added to the need for a vaccine to protect both salmon and trout. At present no licensed vaccines are available in Europe, leaving antibiotics as the only course of action to contain disease outbreaks. Outbreaks generally occur in fry at temperatures between 10 and 15 °C. Recently outbreaks in larger fish have given added impetus to the development of a vaccine which can provide long term protection from this highly heterogeneous pathogen. Most fish injectable vaccines are formulated with oil emulsion adjuvants to induce strong and long lasting immunity, but which are known to cause side effects. Alternative adjuvants are currently sought to minimise these adverse effects.The current study was performed to assess the efficacy of a polyvalent, whole cell vaccine containing formalin-inactivated F. psychrophilum to induce protective immunity in Atlantic salmon. The vaccine was formulated with an adjuvant containing squalene and aluminium hydroxide, and was compared to a vaccine formulated with a traditional oil adjuvant, Montanide ISA 760VG, and a non-adjuvanted vaccine. Duplicate groups of salmon (23.5 ± 6.8 g) were vaccinated with each of the vaccine formulations or phosphate buffered saline by intraperitoneal injection. Fish were challenged by intramuscular injection with F. psychrophilum six weeks post-vaccination to test the efficacy of the vaccines. Cumulative mortality reached 70% in the control salmon, while the groups of salmon that received vaccine had significantly lower mortality than the controls (p = 0.0001), with no significant difference in survival between vaccinated groups. The squalene/alum adjuvant was safe, more readily metabolised by the fish and induced less histopathological changes than the traditional oil adjuvant.

Protective efficacy of combined trivalent inactivated ISA 71 oil adjuvant vaccine against avian influenza virus subtypes (H9N2 and H5N1) and Newcastle disease virus.

Aim:The objective of the present study was to prepare a trivalent inactivated vaccine of Newcastle disease virus (NDV), H5N1, and H9N2 viruses.Materials and Methods:Three monovalent and a trivalent vaccines were prepared by emulsifying inactivated NDV (LaSota strain), reassortant H5N1, and H9N2 viruses with Montanide ISA 71 oil adjuvant. Parameters used for evaluation of the efficacy of the prepared vaccines in specific pathogen-free chickens were cellular immunity assays (blastogenesis, interferon gamma, interleukin 1 [IL1], and IL6), humoral immunity by hemagglutination inhibition, protection percentage, and shedding.Results:A single immunization with trivalent vaccine-enhanced cell-mediated immunity as well as humoral immune response with 90% protection against challenges with highly pathogenic avian influenza (HPAI) H5N1 and low pathogenic (LP) avian influenza H9N2 viruses with 100% protection after challenge with NDV.Conclusion:Development and evaluation of the trivalent vaccine in the study reported the success in preparation of a potent and efficacious trivalent vaccine which is a promising approach for controlling HPAI H5N1, LP H9N2, and ND viral infections.

Optimization of inactivated H5N9 highly pathogenic avian influenza vaccine and inactivated Salmonella enterica serovar Typhimurium vaccine with antigen dose and prime-boost regimen in domestic ducks

Owing to the increase in the number of diseases affecting ducks and the demand for food safety by consumers, vaccination has become one of the factors that influence duck meat productivity. The highly pathogenic avian influenza (HPAI) virus is one of the most prevalent and causes one of the most lethal diseases in domestic ducks, and Salmonella enterica serovar Typhimurium is a food-borne pathogen persistent in the domestic duck population. To better understand the optimal usage of HPAI and S. enterica serovar Typhimurium vaccines, we aimed to determine antigen dose, oil and gel adjuvant usage with prime-boost regimen, and vaccination age, inducing the best immune response in ducks, without an effect on body weight gain. In the case of the inactivated H5N9 vaccine, a single dose of vaccine was inadequate to induce proper antibody titer when administered to day-old ducks, which necessitates boost vaccination. Administration of the oil-adjuvanted H5N9 vaccine administration in day-old and 2-week-old ducks resulted in a lower body weight at the time of slaughtering, compared to that of gel-adjuvanted H5N9 vaccine. However, gel-adjuvanted H5N9 vaccine failed to induce proper immune response to an extent recommend by OIE–World Organization for Animal Health. In the case of the Salmonella enterica serovar Typhimurium vaccine, a moderate or low dose of vaccine was appropriate for day-old ducks receiving the gel prime-oil boost vaccination. Single vaccination with oil adjuvants affects the mean body weight of 7-week-old ducks, suggesting that the gel adjuvant is more suitable for meat production. We expect that the use of adjuvants in a prime-boost regimen and at antigen doses set in this study will be helpful to maximize body weight in the case of domestic duck production at the actual farm site.

Improved vaccine strategies of infectious bronchitis disease to reduce shedding of virulent virus from infected birds

Infectious bronchitis (IB) threatens the economies of entire nations, by adversely affecting the backyard farmers, poultry producers and poultry industry throughout the world. Infectious bronchitis virus (IBV), a member of the Coronaviridae family, is probably one of the most avian pathogens prevalent in the poultry industry worldwide. In the field which presents difference structures, especially in the S1 spike protein. Complicated immune response against IBV due to few similarities between serotypes. High mutation rate of the virus, in addition to the management and environmental factors, compromise the efficacy of the available vaccines and difficult the control of disease. Prepared effective IB vaccines from any IBV strain stimulates the immunity widely against morbidity and mortality after challenge with virulent IBV strains. On the other hand, vaccinates with live IBV vaccines do not reduce infection or viral shedding after challenge. In order to compare the prepared IBV vaccines taken four different IBV genotypes to determine stimulating immunity and the amount of viral shedding after challenge, two hundred fifty one day broiler chicks divided into five groups and vaccinated with oil-adjuvant vaccines prepared of Iraqi isolates (II, I-II, I- III and I-IV). different inactivated IB viruses including strains QX, CH Baghdad M 2014, CH Baghdad F1 2013, CH Babylon F2 2013, and an allantoic fluid control. Using a hemagglutination inhibition test for serum analysis after challenge with virulent IBV (Variant2) to knowledge antibody content against each of the vaccine antigens, Monitored the vaccinated birds daily for of morbidity and mortality were recorded, and used PCR to determine the amount of viral copy of examined clinical samples in selected periods of viral shedding. All vaccines used in the study gave good protection against morbidity and mortality, except the control group. Homologous vaccines gave good protection and lowest viral shedding in the trachea, kidney and feces compared to the heterogeneous vaccines.Key word: infectious bronchitis disease, inactivated vaccines, hemagglutination inhibition, viral load, challenge.

Immunologic evaluation of 10 different adjuvants for use in vaccines for chickens against highly pathogenic avian influenza virus

Avian influenza viruses (AIV) are a threat to poultry production worldwide. Vaccination is utilized as a component of control programs for both high pathogenicity (HP) and low pathogenicity (LP) AIV. Over 95% of all AIV vaccine used in poultry are inactivated, adjuvanted products. To identify the best formulations for chickens, vaccines were prepared with beta-propiolactone (BPL) inactivated A/British Columbia/314514-1/2004 H7N3 LP AIV using ten commercially available or experimental adjuvants. Each vaccine formulation was evaluated for immunogenicity in chickens. Challenge studies with an antigenically homologous strain of HPAIV were conducted to compare protection against mortality and measure reductions in virus levels in oral swabs. The four best adjuvants from the studies with BPL inactivated antigen were selected and tested identically, but with vaccines prepared from formalin inactivated virus. Mineral and vegetable oil based adjuvants generally induced the highest antibody titers with 100% seroconversion by 3weeks post vaccination. Chitosan induced positive antibody titers in 100% of the chickens, but the titers were significantly lower than those of most of the oil based adjuvants. Antibody levels from calcium phosphate and alginate adjuvanted groups were similar to those of non-adjuvanted virus. All groups that received adjuvanted vaccines induced similar levels of protection against mortality (0–20%) except the groups vaccinated with calcium phosphate adjuvanted vaccines, where mortality was similar (70%) to groups that received non-adjuvanted inactivated virus or no vaccine (60–100% mortality). Virus shedding in oral swabs was variable among the treatment groups. Formalin inactivated vaccine induced similar antibody titers and protection against challenge compared to BPL inactivated vaccine groups. These studies support the use of oil adjuvanted vaccines for use in the poultry industry for control for AIV.