Oil Adjuvant Vaccine Research Articles

Optimum processing conditions for a trivalent-inactivated bovine viral diarrhea virus (BVDV) vaccine using field strains and immunogenicity of candidate formulations with different adjuvants.

Bovine viral diarrhea virus (BVDV) is among the common bovine pathogens worldwide. One of the prominent protection measures of BVDV is vaccination. This study aimed to determine the growth characteristics, inactivation kinetics of vaccine candidates using local BVDV strains [TR-26 (BVDV-1f), TR-21 (BVDV-1l), and TR-15 (BVDV-2b)], and the serological response in experimental animals to inactivated BVDV vaccine formulations prepared with different adjuvants. Optimum MOI values for BVDV strains TR-26, TR-21, and TR-15 were determined as 0.1, 1.0, and 0.01, respectively. In addition, growth curves of TR-26, TR-21, and TR-15 strains were created, and it was determined that they reached the highest titers at 12, 48, and 36h p.i., respectively. The strains TR-26, TR-21, and TR-15 with titers of 106.5, 106.5, and 105.25 TCID50/ml were completely inactivated by 1 mM binary ethyleneimine (BEI) at the 10th, 16th, and 10th hours of treatment, respectively. Guinea pigs were immunized with four vaccine formulations (F1, F2, F3, F4), two with aluminum-based [Al(OH)3, Al(OH)3+Saponin] and two with oil-based (ISA 50 and ISA 206) adjuvants. Neutralization tests were applied to determine the humoral immune response developed after vaccination. Both homologous and heterologous BVDV strains were used for evaluations. Oil adjuvanted vaccines were more efficient to induce antibody titers compared to Al(OH)3-based vaccines. In addition, between the oil adjuvanted vaccines, the titers of neutralizing antibodies obtained by Montanide® ISA 206 formulation were significantly higher than in Montanide® ISA 50 (p < 0.05). Post-vaccinal neutralizing antibodies were detected in the first sampling at 21st day and lasted longer than a 111 days period. The highest antibody response in Guinea pigs was for the strain TR-15. The availability of using BVDV-lf, 1l, and 2b local strains in vaccines and their effectiveness against homologous and heterologous strains have been demonstrated.

Natural Bacterial Co-Infection in Farmed European Sea Bass Intended for Experimental Research in Sicily, Southern Italy: Pathological Findings

In mariculture facilities, bacterial infections pose significant production challenges, with potentially catastrophic impacts on fish species. Bacterial co-infections are a widespread phenomenon in the natural marine environment, although their impact on aquatic organisms remains poorly investigated. This study aimed to detail the pathological findings associated with a natural bacterial co-infection caused by three different pathogens, namely Photobacterium damselae subsp. piscicida, Tenacibaculum maritimum and Vibrio sp., as the cause of mass mortality in European sea bass. The fish had been reared in open-net cages in Sicily and later transferred for experimental research purposes to a user establishment after immunization with an inactivated vaccine. Macroscopic, cytological and histopathological examinations were performed on 109 animals, and bacterial species were identified by the 16S rRNA gene. Overall, ulcerative skin lesions, necrotizing myositis and tail rot with occasional tail loss were associated with tenacibaculosis and vibriosis, while P. damselae subsp. piscicida mainly caused granulomatous inflammation in the spleen and head kidney. Finally, an injection site reaction due to the oil-adjuvanted vaccine administered intraperitoneally was observed in the abdominal fat. Understanding the impact of bacterial pathogens is essential to manage the health and welfare of farmed fish, and the importance of a good health monitoring program cannot be overstated to avoid outbreaks and the possible emergence of new pathogens due to the intensification of the production systems, antibiotic resistance and climate changes. The study would also highlight the importance of the quarantine period when animals supplied for research come from aquaculture farms and how the main goal in the near future should be to better define the procedures to provide completely pathogen-free animals.

Vaccinated Atlantic salmon (Salmo salar L.) maintain a specific antibody response throughout the seasonal fluctuations of a full commercial production cycle in sea: a case study

Vaccination is a critical prophylactic measure to prevent disease outbreaks in Atlantic salmon (Salmo salar L.) and multivalent oil-adjuvanted vaccines administered intraperitoneally (IP) are widely used for this purpose. The Atlantic salmon in this observational study were sampled during commercial production in a salmon farm in Northern Norway. Fish were sampled in the hatchery prior to vaccination, and further every 6 weeks after sea transfer up until slaughter. The key findings revealed that Atlantic salmon vaccinated IP with a commercial multivalent oil-based vaccine developed specific and long-lasting antibody responses against A. salmonicida, V. anguillarum, Y. ruckeri, and IPNV for up to 20 months post-vaccination. However, there was variation in the measured specific antibody response to the different antigens. Notably, the antibody responses against A. salmonicida and V. anguillarum antigens were higher and more prolonged compared to the antibody responses against Y. ruckeri and IPNV antigens. Histological examination showed presence of vaccine-induced granulomas in the pancreas at the injection site for up to 50 weeks post-vaccination and V. anguillarum antigens were found in the granulomas up to 44 weeks post-vaccination. There were also individual IgM-positive cells present in these vaccine-induced granulomas, and qPCR confirmed increased gene expression of membrane-bound and secretory IgM up to 37 weeks post-vaccination. Altogether the qPCR data of membrane and secretory IgM suggests local production of IgM in the vaccine-induced granulomas, while the head kidney might be responsible for the long-term secretion of IgM. Neither the low temperature the fish experienced for two winter seasons (below 5 °C) nor the seasonal changes in photoperiod affected the vaccine-induced specific antibody responses.

Enhanced Effects of ISA 207 Adjuvant via Intradermal Route in Foot-and-Mouth Disease Vaccine for Pigs.

In South Korea, a mandatory nation-wide foot-and-mouth disease (FMD) vaccination policy is in place. However, a major side effect of the current method of intramuscular (IM) administration of oil-adjuvanted FMD vaccines is the formation of granulomas in the muscles of pigs. To address this issue, we assessed the possible application of intradermal (ID) vaccination. Initially, we compared the serological immune response in specific pathogen-free pigs inoculated with FMD vaccines formulated with eight different adjuvants, administered twice at the neck site using a syringe with a needle via the ID route. Among the formulations (water-in-oil-in-water (W/O/W), oil-in-water (O/W), and polymer nanomaterials), ISA 207 of W/O/W was the most effective in inducing immunogenicity followed by ISA 201 of W/O/W. ISA 207 was further tested in formulations of different antigen doses (12 or 1.2 μg) delivered via both IM and ID routes. All four treatments successfully protected the pigs against FMD virus challenges. To assess the feasibility of the field application of the vaccines with ISA 207, we conducted ID vaccination of conventional pigs using a needle-free device, resulting in the detection of significant levels of neutralizing antibodies. ISA 207 was shown to be superior to ISA 201 in inducing immunogenicity via the ID route. In conclusion, ISA 207 could be a suitable adjuvant for ID vaccination in terms of vaccine efficacy for FMD, allowing for alternate use of ID vaccination and subsequent reduction in the incidences of granuloma formation in the field.

Effects of adding antibiotics to an inactivated oil-adjuvant avian influenza vaccine on vaccine characteristics and chick health

During poultry immunization, antibiotics are typically added to inactivated oil-adjuvant avian influenza (AI) vaccines. Here, we evaluated the effects of adding ceftiofur, a third-generation cephalosporin, to an AI vaccine on vaccine stability and structure and on chick growth, immune efficacy, blood concentrations, biochemical and immunological indices, and gut microbiota. The results demonstrated that neither aqueous ceftiofur sodium nor ceftiofur hydrochloride oil emulsion formed a stable mixture with the vaccine. Adding ceftiofur formulations, particularly ceftiofur hydrochloride, at >4% significantly destabilized the vaccine's water-in-oil structures. Adding ceftiofur also increased vaccine malabsorption at the injection site; specifically, adding ceftiofur hydrochloride reduced H5N8 and H7N9 antibody titers after the first immunization (P < 0.05) and H7N9 antibody titers after the second immunization (P < 0.01). Serum drug concentrations did not differ significantly between the groups with ceftiofur sodium and hydrochloride addition. Ceftiofur addition increased postvaccination chick weight loss; compared with the vaccine alone, ceftiofur sodium-vaccine mixture increased chick weight significantly (P < 0.05). Ceftiofur addition also increased stress indices and reduced antioxidant capacity significantly (P < 0.05 or P < 0.01). Vaccination-related immune stress reduced gut microbiota diversity in chicks; ceftiofur addition reversed this change. AI vaccine immunization significantly reduced the relative abundance of Lactobacillus and Muribaculaceae but significantly increased that of Bacteroides and Eubacterium coprostanoligenes group. Ceftiofur addition restored the gut microbiota structure; in particular, ceftiofur hydrochloride addition significantly increased the abundance of the harmful gut microbes Escherichia-Shigella and Enterococcus, whereas ceftiofur sodium addition significantly reduced it. The changes in gut microbiota led to alterations in metabolic pathways related to membrane transport, amino acids, and carbohydrates. In conclusion, adding ceftiofur to the AI vaccine had positive effects on chick growth and gut microbiota modulation; however, different antibiotic concentrations and formulations may disrupt vaccine structure, possibly affecting vaccine safety and immunization efficacy. Thus, the addition of antibiotics to oil-adjuvant vaccines is associated with a risk of immunization failure and should be applied to poultry with caution.

Inflammatory responses in Atlantic lumpfish (Cyclopterus lumpus L.) after intraperitoneal injection of a vaccine against Aeromonas salmonicida and Vibrio salmonicida at different water temperatures.

Studying inflammatory responses induced by vaccination can contribute to a more detailed understanding of underlying immune mechanisms in lumpfish (Cyclopterus lumpus). Tissue samples from lumpfish intraperitoneally immunized with a divalent oil-adjuvanted vaccine (Aeromonas salmonicida and Vibrio salmonicida) at water temperatures of 5, 10, and 15°C were collected at 630 day degrees and 18 weeks post injection. The relative amount of secretory and membrane-bound immunoglobulin M (IgM) gene transcripts in the head kidney was determined by qPCR. Vaccine-induced inflammatory lesions were assessed on histological sections of abdominal pancreatic/intestinal tissue from vaccinated fish in all three temperature groups. Inflammatory cells forming dense aggregations in lesions showed proliferative activity, many of which were identified as eosinophilic-granulocyte-like cells. IgM+ cells were scattered in inflammatory tissue dominated by connective tissue, showing no difference in numbers between lesions from fish vaccinated at 5, 10, and 15°C. Relative gene expression analysis of secretory and membrane-bound IgM revealed low overall expression in the head kidney of vaccinated fish at both 630 day-degrees and 18 weeks post injection. The results of this study indicate that the vaccine stimulated prolonged local inflammatory responses at the injection site, which were not influenced by temperature.

Water-in-oil adjuvant challenges in fish vaccination: An experimental inactivated adjuvanted vaccine against betanodavirus infection in Senegalese sole.

The extensive growth of intensive fish farming has led to a massive spread of infectious diseases. Nervous necrosis virus (NNV) is the causative agent of the viral encephalo- and retinopathy disease which has become a major threat for fish farming all over the globe. The devastating mortality rates recorded in disease outbreaks, especially when infected specimens are at early stages of development, have a high economic impact on the sector. Currently, vaccines are the most cost-effective preventing tool in the fight against viruses. Inactivated vaccines have the advantage of simplicity in their development at the same time as present the antigen in a similar manner than the natural infection in the host. Nevertheless, they usually trigger weaker immune responses needing adjuvants to boost their effectiveness. In this work, we have intraperitoneally vaccinated Senegalese sole juveniles (Solea senegalensis) with a previously designed inactivated vaccine against NNV based on binary ethylenimine (BEI), mixed or not with an oil-adjuvant. Our results demonstrated the potential activation of different immune pathways when the vaccine was administered alone compared to the oil-adjuvanted vaccine, both resulting in an equivalent partial improvement in survival following a NNV challenge. However, whilst the vaccine alone led to a significant increase in specific antibodies, in the adjuvanted version those antibodies were kept basal although with a slight improvement in their neutralization capacity. At transcriptional level, neither vaccine (adjuvanted or not) triggered the immune system activation during the vaccination period. However, after NNV infection, the BEI-inactivated vaccines alone and oil-adjuvanted both elicited the stimulation of antiviral responsive genes (rtp3, herc4), antigen presentation molecules (mhcii) and T-cell markers (cd8a) in the head-kidney. Additionally, the oil-adjuvanted vaccine appears to stimulate mediator cytokines (il6) and B-cell markers (ight and ighm). Surprisingly, when the adjuvant was administered alone, fish showed the highest survival rates concomitantly with a lack of NNV-IgM production, pointing to the possible induction of different immune pathways than the B-cell responses via antibodies by the adjuvant. Since this combined vaccine did not succeed in the full extension of protection against the pathogen, further studies should be performed focusing on unravelling the molecular mechanisms through which adjuvants trigger the immune response, both independently and when added to a vaccine antigen.

Evolution of prevalent H9N2 subtype of avian influenza virus during 2019 to 2022 for the development of a control strategy in China

The H9N2 subtype of avian influenza virus (H9N2 AIV) has caused significant losses in chicken flocks throughout China. At present, consensus has been reached that field isolates of H9N2 underwent antigenic drift to evolve into distinct groups with significant antigenic divergence from the commercially available vaccines in China. This project continues to monitor the evolution characteristics of H9N2 hemagglutinin (HA) genes in China over the past 3 yr. The results showed that the current circling H9N2 viruses were diversified into h9.4.2.5 subclade, which was genetically distant from commonly used commercial vaccine strains. Compared with vaccine strains or 2014 strains, more than 42.1% of the variable antigenic sites in recent 3 yr' strains have shown significant changes and these stacked changes have caused significant differences in antigenicity. We constructed a recombinant vaccine strain rCQY-GHHA, which uses A/Chicken/China/SichuanCQY/2014 as the framework and A/Chicken/China/SichuanGH/2020 strain, which meets the recent viral antigenic characteristics, as the HA gene donor. The recombinant strain was prepared as an oil-adjuvant inactivated vaccine following an industrial process. The results of the immune protection experiment showed that the rCQY-GHHA vaccine was better than the commercial vaccine strain SS in reducing the morbidity, pathological lesion, virus shedding, and viral load. These results provide a reference for the control of H9N2 AIV in China.

Effect of foot-and-mouth disease vaccination on acute phase response and milk production in the Holstein-Friesian crossbred cow

The study investigated the effects of FMD vaccination on acute phase response and milk composition in the HF crossbred cows (n = 12) using a cross-over experimental design. In trial 1, one group (n = 6) received inactivated trivalent oil-adjuvanted FMD vaccine [day post-vaccination, (dpv) 0], while the mock-vaccinated group received saline (n = 6). After a cooling period of 15 days, the trial was repeated by swapping groups. The body temperature, dry matter intake (DMI) and milk yield were recorded. Haemato-biochemical parameters, haptoglobin and cortisol concentrations were also assessed. A significant (p < 0.05) increase in the neutralizing antibody response to FMDV serotype O and Asia1 indicated a positive immune response. A significant (p < 0.05) increase of 0.4° to 0.6°C in the body temperature, decrease of 0.7–0.8 kg in DMI along with an increase in the serum haptoglobin, total leukocyte count and neutrophils within dpv 2 indicated acute phase response in the FMD vaccinated group. Among the milk constituents, only milk fat (p = 0.053) was significant. It was concluded that FMD vaccination induced acute phase response within dpv 3 in the crossbred cows and caused a non-significant reduction in the milk yield on the day of vaccination.

Complete Genome Sequencing of an Embryonated Chicken Egg-Adapted Duck atadenovirus A.

Egg drop syndrome (EDS) is prevalent in industrial poultry globally. This disease is caused by Duck atadenovirus A or EDS virus (EDSV), a member of the genus Atadenovirus under the family Adenoviridae. The disease is attributed to significant economic losses in the poultry industry worldwide due to a drop in egg production, reduction in egg quality, and failure to reach maximum egg production. Oil-adjuvant inactivated vaccines, which are widely used in the poultry industry, provide good protection for immunized chickens against EDS. This study aimed to genetically and phylogenetically analyze the full-length genome of an embryonated chicken egg-adapted EDSV strain 127. After extraction of viral DNA from the allantoic fluid, overlapping fragments of the viral genome sequence were generated by polymerase chain reaction (PCR) using 25 pairs of primers. Purified PCR products were subjected to complete genome sequencing by the next-generation sequencing (NGS) approach. The nucleotide homology observed between genomes of the studied strain and that of the original strain 127 (NC_001813) of laying chickens was 99.9%. Its genome was 33,213 bp in length, with a G + C content of 43.01%. A comparison of the genome sequence of the egg-adapted virus with strain 127 revealed only three non-synonymous single-nucleotide polymorphisms (SNPs) between these viral genome sequences. Two mutations of S320G and I62K out of these SNPs were found within the coding regions of fiber and hypothetical proteins which may play a role in the adaptation of EDSV in the embryonated chicken eggs. The full genome sequencing of EDSV using NGS techniques provides insights into the discovery of genetic variants. Moreover, the genome sequence information of the EDSV provides valuable data for vaccine development in near future.

Comparative Assessment of Serum Biochemical Markers from Cattle and Buffaloes Vaccinated with Three Different Oil Adjuvant Vaccines of Hemorrhagic Septicemia from Punjab, Pakistan

Haemorrahgic Septiceamia (H.S) is a deadly, sub-acute livestock disease of cattle and buffalo in Southeast Asia including Pakistan. A whopping 98% case fatality rate renders vaccination a mandatory prophylactic control measure to counter HS. Very little information is available on serum biochemical profile of the HS vaccinated animals. This study was conducted to investigate the serum biochemistry of the vaccinated cattle and buffalo calves and adults alike. Three different experimental oil adjuvant vaccines were produced for Pasturella multocida serotype B:2 (locally prevalent). N=80 healthy cattle and buffalo (calves and adults) were divided into four groups. Each group consisted of 20 animals (10 calves and 10 adults). Group A was injected with vaccine prepared with Montanide ISA-50; Group B with vaccine prepared from Montanide ISA-206 while Group C with a vaccine produced from Liquid paraffin and Lanolin. Group D animals served as non-immunized control. Blood samples were collected from each animal at zero-day, after booster at 90 days, and then every quarter for one year. Twelve biochemical parameters were assessed by ANOVA and Kruskal Wallis Test. Post hoc multiple comparisons were done for glucose levels. It was concluded that vaccinating both cattle and buffalo calves and adults with H.S. vaccine formulated with three different adjuvants did not have a statistically significant effect on serum biochemistry of vaccinated animals compared to controls.

IMPACT OF GLYCEROL AND DIMETHYL SULFOXIDE ON THE PERSISTENCE OF PASTEURELLA MULTOCIDA DURING ITS PRESEVATION AT DIFFERENT TEMPERATURES

Bacterium Pasteurella multocida type B:2 is the causative agent of Hemorrhagic Septicemia in bovines in Pakistan. This organism is also being used for oil adjuvanted (Montanide ISA 50 V2) vaccine for mass vaccination in cattle &amp; buffaloes in Punjab, Pakistan. A study was conducted to study the impact of glycerol and dimethyl sulfoxide (DMSO) on persistence of P. multocida duringits course of storage at 0, 4 and – 20 °C. Pure seed of P .multocida was grown in Brain Heart Infusion(BHI) broth at pH 7.4 and incubated at 37 °C for 18 hrs. in shaking incubator. The growth was observed for its purity microscopically as well as culturing on MacConkey’s &amp; Nutrient agar slants. The pure culture was divided into three parts. One part was added with 5 % sterilized DMSO (final concentration) and second part was added with 10 % sterilized DMSO (final concentration) and 15 % glycerine (final concentration) while third part was kept as control without addition of DMSO and glycerine. All three parts were aliquoted (1 mL) in sterilized 1.5 mL eppendroff tubes and stored at three different temperatures i.e 0, 4 and – 20 °C. Eppendroff tubes from different temperatures were thawed in water bath (22 °C) and subjected to direct culturing on BHI broth, microscopic examination, purity testing on slants, culture turbidity / Optical Density (OD) values, dry biomass calculation and mice inoculation test for three months with 15 days intervals. The results indicated that pure P. multocida culture mixed with 10 % sterilized DMSO and 15 % sterilized glycerol stored at – 20 °C survived for three months and can be used for HS vaccine production without losing its survival.

Detection of humoral and cell mediated immune responses among breeder ducks vaccinated against riemerellosis

Riemerellosis is an infectious disease that primarily affects young ducklings, although it can infrequently be manifested in a chronic localised form in older ducks. Though an inactivated vaccine has been found to be most effective in preventing the disease in ducklings, its potency in adult breeder ducks has not been assessed yet. To investigate the same, 200 Kuttanad breeder ducks maintained in the University Poultry and Duck Farm (UPDF), Mannuthy were grouped into two, of 100 birds each, T1 being the control group and T2, the treatment (vaccinated) group. The oil-adjuvanted inactivated vaccine, prepared as per the previously standardised protocol, was administered to the T2 group in two doses, one week apart. Blood samples in serum vials, 20 each from T1 and T2, were collected on days 0, 14, 28, 56 and 90 post-immunisation (PI) whereas blood samples in heparin vials, eight each from both the groups, were collected on days 0, 14, and 28 PI. Humoral immunity (HI) and cell mediated immunity (CMI) in the adult ducks were assessed by enzyme-linked immunosorbent assay (ELISA) and lymphocyte proliferation assay (LPA), respectively. The two assays revealed that the inactivated vaccine elicited a good immune response in the adult ducks, with HI noticed until 90th day PI and an increasing CMI that peaked on 28th day PI.

Clinicopathological study on some vaccines in Barki ewes

Vaccines are the most effective method for animal immunization against infectious diseases. This work aimed to study the effect of some vaccines commonly, used in sheep, on some innate immunological and clinicopathological parameters. For this purpose, forty-five Barki ewes were housed at the sustainable development Centre of Matrouh resources farm. They were divided into: Pox group: fifteen ewes were injected with live-attenuated pox vaccine. FMD+RVF group: fifteen ewes were injected separately with two vaccines (polyvalent inactivated foot and mouth disease oil adjuvant vaccine and rift valley inactivated vaccine). Ultrabac group: fifteen ewes were injected with 2.5 ml bacterial toxoid (Ultrabac® 8, Zoetis). Blood samples were collected then immunological and clinicopathological parameters were estimated and statistically analyzed. The three studied groups showed a significant (P˂0.05) increase in the activity of pro-inflammatory cytokines, ceruloplasmin, and oxidative stress, associated with serious clinicopathological changes (anemia, leukocytosis, increased liver and kidney functions, hyperglobulinemia, hypoalbuminemia). These alterations peaked on the 14th day, and subsequently moved towards their baseline values. They were more prominent and sustained in the Ultrabac group (with selective hyperproteinemia) than in the other two groups. The FMD+RVF group displayed a higher degree of cytokines activity, APR, oxidative stress, leukocytosis, and AST values than the Pox group. Conclusion: Sheep vaccination evokes an innate immune response which results in clinicopathological changes. These alterations are more pronounced in bacterial and combined vaccines than viral and single vaccines. The first 14 days after vaccination is a critical period and needs proper management.

Live recombinant Newcastle disease virus vectored vaccine expressing the haemagglutinin of H9N2 avian influenza virus suppresses viral replication in chickens

ABSTRACT In 2020, the Y280-lineage H9N2 low-pathogenic avian influenza virus (LPAIV) was introduced into South Korea for the first time. Current vaccines are focused on the control of Y439-like viruses; however, there are continuous reports of decrease in egg production and secondary infections caused by Y280-lineage H9N2 LPAI infection in chickens. Therefore, there is an urgent need to develop effective novel vaccines against Y280-lineage H9N2 LPAI. Most commercialized avian influenza vaccines are oil-adjuvanted inactivated vaccines, which are labour-intensive to administer and require higher dosage. In this study, rK148/Y280-HA, a novel recombinant Newcastle disease virus (NDV) vectored vaccine against Y280-lineage H9N2 LPAI, was developed and evaluated using two mass-applicable administration methods, spray vaccination and drinking water vaccination. Regardless of low serum antibody haemagglutination inhibition titres against NDV and Y280-lineage H9N2 LPAI after applying the rK148/Y280-HA vaccine, vaccination with either administration method protected chickens against virulent NDV and Y280-lineage H9N2 LPAIV after the challenge. Taken together, these results indicate that the rK148/Y280 vaccine can be administered using facile mass-application methods to provide protection against the Y280-lineage LPAI. RESEARCH HIGHLIGHTS NDV vectored vaccine harbouring Y280-lineage H9N2 HA protein was successfully generated. NDV vectored vaccine provides protection against NDV. NDV vectored vaccine with H9N2 HA protects against homologous H9N2 LPAIV.

A single amino acid substitution in the VP2 protein of Indian foot-and-mouth disease virus serotype O vaccine strain confers thermostability and protective immunity in cattle.

Foot-and-mouth disease (FMD) is a significant threat to animal health globally. Prophylactic vaccination using inactivated FMD virus (FMDV) antigen is being practised for the control in endemic countries. A major limitation of the current vaccine is its susceptibility to high environmental temperature causing loss of immunogenicity, thus necessitating the cold chain for maintenance of its efficacy. Hence, the FMD vaccine with thermostable virus particles will be highly useful in sustaining the integrity of whole virus particle (146S)during storage at 4°C. In this study, 12 recombinant mutants of Indian vaccine strain of FMDV serotype O (O/IND/R2/1975) were generated through reverse genetics approach and evaluated for thermostability. One of the mutant viruses, VP2_Y98F was more thermostable than other mutants and the parent FMDV. The oil-adjuvanted vaccine formulated with the inactivated VP2_Y98F mutant FMDV was stable up to 8 months when stored at 4°C and induced protective antibody response till dpv 180after primary vaccination. It is concluded that the VP2_Y98F mutant FMDV was thermostable and has the potential to replace the parent vaccine strain.

Evaluation of Efficacy of Oil Adjuvanted H5N6 Inactivated Vaccine against Highly Pathogenic H5N6 and H5N1 Influenza Viruses Infected Chickens.

Over the last 20 years, circulating highly pathogenic (HP) Asian H5 subtype avian influenza viruses have caused global pandemics in poultry and sporadic infections in humans. Vaccines are a desirable solution to prevent viral infections in poultry and reduce transmission to humans. Herein, we investigated the efficacy of an oil-adjuvanted inactivated H5N6 vaccine against highly pathogenic H5N6 and H5N1 influenza virus infections in chickens. The polybasic amino acid cleavage site depleted HA gene and NA gene of A/Waterfowl/Korea/S57/2016 (clade 2.3.4.4) (H5N6) was assembled with the rest of the A/PR/8/34 (H1N1) genes to construct the vaccine virus. The vaccine virus was propagated in fertilized eggs, partially purified using a tangential flow filtration (TFF) system, and inactivated using formalin. The chickens were intramuscularly immunized with 384 HA, 192HA, and 96HA units of oil-adjuvanted inactivated H5N6 vaccine. Antibody titer, survival rate, and lung pathology were evaluated against the homologous H5N6: A/waterfowl/Korea/S57/2016 (clade 2.3.4.4) and heterologous H5N1: A/Hong Kong/213/2003 (clade 1) viruses 12 and 4 weeks post-vaccination (p.v.), respectively. Data were statistically analyzed using the Mann-Whitney U test. The 384HA (n = 10) and 192HA (n = 5) antigen-immunized chickens showed 100% survival after lethal infections with homologous H5N6, and no virus shedding was observed from tracheal and cloacal routes. All chickens that received the 384HA vaccine survived the challenge of heterologous H5N1 after 4 weeks of immunization. The chickens that received the 384HA vaccine showed mean HI titers of 60 and 240 after 12 and 4 weeks of vaccination, respectively, against HP H5N6, whereas a mean HI titer of 80 was observed in sera collected 4 weeks after vaccination against HP H5N1. Our findings indicate that one dose of 384HA oil-adjuvanted inactivated H5N6 vaccine can induce a long-lasting immune response against both homologous H5N6 and heterologous H5N1 infections in chickens.

Effects of a DNA and multivalent oil-adjuvanted vaccines against pancreas disease in Atlantic salmon (Salmo salar) challenged with salmonid alphavirus subtype 3

Salmonid alphavirus (SAV) causes pancreas disease (PD) in Atlantic salmon (Salmo salar). In seawater-farmed salmonids in the southern part of Norway SAV subtype 3 (SAV3) is dominating. PD continues to cause significant economic and fish health concerns in this region despite years of extensive use of oil-adjuvanted vaccines (OAVs) containing inactivated whole virus (IWV) antigens. In the current study, three commercially available PD vaccines were tested. Group A got a DNA vaccine (DNAV) injected intramuscularly (i.m.) plus an OAV without a PD component injected intraperitoneally (i.p.). Groups B and C got different OAV IWV vaccines injected i.p., respectively. The control group was i.p. injected with saline. Approximately 12 weeks after vaccination, the post smolt groups were challenged in seawater with SAV3 by cohabitation. Samples were collected pre-challenge, and at 19, 54 and 83 days post-challenge (dpc). There were no differences in growth or visible intraperitoneal side effects between the immunized groups prior to challenge. Fish in group A had significantly higher SAV3 neutralizing antibody titers than the other groups pre-challenge and significantly lower SAV3 viremia levels than the control group at 19 dpc. Fish in group A had significantly more weight gain than the other groups measured at 54 and 83 dpc. Prevalence and severity of heart necrosis at 19 dpc and loss of exocrine pancreas tissue at 54 and 83 dpc were significantly lower in groups A and B compared to group C and controls. The cumulative mortality in the control group during the challenge period was 10.5%. Group A experienced the lowest mortality (6.4%) albeit not statistically different from the controls. The results suggest that DNAV may reduce the clinical and economic impact of PD by improved protection against SAV3-induced changes in pancreas tissue and growth impairment.

Assessment of free radicals and reactive oxygen species milieu in nanoparticles adjuvanted outer membrane proteins vaccine against Salmonella typhi.

In this study, calcium phosphate nanoparticles-based (STCNV) and montanide oil adjuvant vaccine (STOAV) containing outer membrane proteins (Omps) of S. Typhi were evaluated for inducing oxidative stress indicators [reduced glutathione (GSH), lipid peroxidation (LPO), catalase, superoxide dismutase (SOD), and total protein] in the tissues of mice after vaccination. The GSH levels though slightly high in the liver, kidney, and lungs of STCNV group were not significantly different from STOAV and the control group (STC). There was no significant difference in LPO levels in any group for any tissue. The significantly lower activities of catalase were observed in the kidney and lungs of the STCNV group as compared to STOAV and STC group, while in the liver, STCNV group revealed lower catalase activity in comparison to the control group. No significant difference in the SOD activities between the two vaccinated groups was observed. The total protein contents in all the organs showed no significant difference in the vaccinated and the control group. The vaccines may induce long-term inflammatory response and consequently damage vital organs; this study revealed no long-term oxidative stress in all the three vital organs, suggesting that these vaccines may not cause oxidative damages in the vital organs of mice.

The Efficacy of a Trivalent Inactivated Salmonella Vaccine Combined with the Live S. Gallinarum 9R Vaccine in Young Layers after Experimental Infections with S. Enteritidis, S. Typhimurium, and S. Infantis.

Worldwide, poultry infections by Salmonella are the cause of significant economic losses, not only due to reduced production (due to fowl typhoid disease), but also considering the efforts and control measures that must be constantly applied, especially due to zoonotic serovars. Poultry is a common reservoir of Salmonella and its transmission into the food chain is a risk for humans. The vaccination of layers plays an important role in the overall efforts to prevent Salmonella infections. An inactivated trivalent vaccine was prepared with S. Enteritidis, S. Typhimurium, and S. Infantis strains. Infection trials were performed to evaluate the efficacy of three vaccination schedules using inactivated and live S. Gallinarum 9R vaccines. For this purpose, at week 5 of life, one subcutaneous dose of live S. Gallinarum 9R vaccine (1–5 × 107 CFU) was given to Groups 1 and 2. At weeks 8 and 11 of life, chickens were also vaccinated with one (Group 1) or two (Groups 2 and 3) intramuscular doses of the inactivated oil-adjuvant trivalent vaccine (1 × 108 CFU/dose of each antigen). Group 4 consisted of chickens that remained unvaccinated (control). At week 14 of life, the efficacy of the vaccination plans was evaluated in three separate inoculation trials with S. Enteritidis, S. Typhimurium, or S. Infantis. After vaccination with the inactivated vaccine, homologous antibody production was observed, and after challenge, a significant reduction in the faecal shedding, invasion, and colonization of S. Typhimurium and S. Infantis was achieved by all vaccination schedules, while the vaccination with at least one dose of the live S. Gallinarum 9R vaccine was necessary to obtain such a significant protection against S. Enteritidis infection.