Bovine Viral Diarrhea Virus Vaccine Research Articles

Outbreak of persistently infected heifer calves with bovine viral diarrhea virus subgenotypes 1b and 1d in a BVDV-vaccinated open dairy herd

Bovine viral diarrhea virus (BVDV) infection has a significant economic impact on beef and dairy industries worldwide. Fetal infection with a non-cytopathic strain may lead to the birth of persistently infected (PI) offspring, which is the main event in the epidemiological chain of BVDV infection. This report describes the birth of 99 BVDV-PI heifer calves within 52 days of birth in a regular BVDV-vaccinated Brazilian dairy cattle herd and the subgenotypes of the infecting field strains. This study was conducted in a high-yielding open dairy cattle herd that frequently acquired heifers from neighboring areas for replacement. The farm monitors the birth of PI calves by screening all calves born using an ELISA (IDEXX) for BVDV antigen detection. All calves aged 1–7 days were evaluated. For positive and suspected results, the ELISA was repeated when the calves were close to one month old. A total of 294 heifer calves were evaluated between February and March 2021. Of these, 99 (33.7 %) had positive ELISA results and were considered PI calves. To evaluate the predominant BVDV species and subgenotypes in this outbreak, whole blood samples were collected from 31 calves born during the study period. All samples were submitted to the RT-PCR assay for the partial amplification of the BVDV 5′-UTR region, and these amplicons were subjected to nucleotide sequencing. Phylogenetic analysis identified BVDV-1b and BVDV-1d in 16 and 13 heifer calves, respectively. In two calves, it was not possible to determine the BVDV-1 subgenotype. Detection of PI animals and monitoring of circulating BVDV subgenotype strains are central to disease control. This study shows that regular BVDV vaccination alone may be insufficient to prevent BVDV infection in high-yielding open dairy cattle herds. Other biosecurity measures must be adopted to avoid the purchase of cattle with acute infections by BVDV or BVDV-PI, which can cause a break in the health profile of the herd and economic losses.

Seroprevalence of bovine viral diarrhea virus and detection of persistently infected (PI) animals in dairy farms of Holeta, central Ethiopia

Bovine viral diarrhea virus (BVDV) is one of the most important pathogens of the reproductive systems that have a significant socio economic impact on the dairy industry. A cross-sectional study was conducted on 17 randomly selected farms out of 133 registered dairy farms in Holeta, a town in the Walmera district of Ethiopia. The study aimed to detect BVDV antigen-positive animals and investigate the seroprevalence of BVDV infection. A total of 337 serum samples were collected from selected farms with no history of BVDV vaccination. The indirect enzyme-linked immunosorbent assay (I-ELISA) test was the screening test used to detect antibodies against BVDV. In contrast, antigencapture ELISA was used for the detection of BVDV antigens in seronegative animals. A logistic regression model was used to assess the association between potential predictors and BVDV exposure. The overall animal level seroprevalence was 15.4%, and 64.7% of the herds had at least one seropositive animal. From 285 seronegative animals, one animal (0.4%) was found positive for BVDV antigen. The same animal was found positive in a double check 21 days later. In this study, cows with a history of abortion (OR = 6.3; 95% CI: 1.61 -13.1), history of repeated breeding (OR = 7; 95% CI: 2.5 - 14.3), animals managed intensively (OR = 4.6; 95% CI: 1.6 - 13.0) and multiparous cows (OR = 3.6; 95% CI: 1.5 - 8.9) had higher proportion of seroreactors in their respective comparison category (p<0.05). Besides, cows with a history of congenital defective calve birth (OR = 15.2; 95% CI: 3.2 - 73.6), adult age groups (OR = 2.9; 95% CI: 1.0-7.9), and cows bred both artificially and natural mating (OR = 4.6; 95% CI: 1.7 - 12.6) were statistically associated with BVDV seropositivity (p<0.05). In conclusion, this report demonstrated the presence of persistently infected (PI) dairy cattle in Ethiopia. Thus, the findings warrant the need for immediate control intervention that involves both screening and culling of PI animals and vaccination.

An investigation into the transmission and control of pestivirus in sheep in Australia.

Border disease virus (BDV) is a member of the pestivirus genus that primarily affects sheep, causing reproductive losses through abortion, still births and the birth of weak lambs. The key characteristic of this disease is the birth of persistently infected (PI) lambs which, after surviving transplacental infection, are born antibody negative, yet virus positive, and thus shed the virus for their entire life and are the primary source of spread within a flock. The cornerstones of BDV control are detection and elimination of PI animals, biosecurity measures to prevent re-infection, and surveillance programs. Recommendations for the control of BDV in sheep are centred around the approach to bovine viral diarrhoea virus (BVDV), the prominent cattle pestivirus species, due to a lack of specific research into BDV control and elimination. In this study, two aspects of a BDV control program were investigated: the effectiveness of the BVDV vaccine, Pestigard®, and the rate of seroconversion in a flock deliberately exposed to known PI lambs. The vaccine appeared to be safe, and the optimal dose was the full cattle dose (2 mL). While vaccination induced high virus neutralising titres to BVDV when administered as either a quarter, half or full dose registered for cattle, the BDV titres achieved were low and unlikely to prevent transplacental infection. In a second study, after exposure of between 2 and 15 days exposure to two PI lambs in confined conditions, only 3 of 66 previously naïve sheep demonstrated seroconversion. This demonstrated a very low rate of transmission and suggested that deliberate exposure to PI lambs at low-risk times for less than 15 days was not likely to be an effective means of achieving seroconversion throughout a flock and, therefore, not provide protection against BDV challenge during gestation.

Development and evaluation of a monoclonal antibody-based blocking ELISA to detect antibodies against the E2 protein of bovine viral diarrhea virus-1

With the rapid development of cattle industry, bovine viral diarrhea virus (BVDV) is becoming widespread in China, which causes serious economic losses to the industry. Effective vaccination and viral surveillance are critical for the prevent and control of BVDV infection. In the present study, the immunogenic domain of E2 protein of BVDV-1 was expressed by prokaryotic pET-28a vector. Monoclonal antibodies (mAbs) against E2 protein were prepared and systemically examined by western blot, immunofluorescence assay, blocking ELISA (bELISA) and virus neutralization test (VNT). The mAb 1E2B3, which showed good reactivity and neutralizing activity to BVDV-1 strains, was selected for ELISA establishment. After a series of screening and optimization, a novel bELISA for highly sensitive and specific detection of BVDV-1 antibodies was established, using HRP-labeled 1E2B3 and recombinant E2 protein. ROC analysis of 91 positive and 84 negative reference bovine serum samples yielded the area under the curve (AUC) of 0.9903. A diagnostic specificity of 96.43 % and a sensitivity of 95.6 % were achieved when the cutoff value was set at 24.31 %. There was no cross reaction to the positive sera of classical swine fever virus (CSFV), BVDV-2, border disease virus (BDV), bovine parainfluenza virus type 3 (BPIV3), infectious bovine rhinotracheitis virus (IBRV), foot-and-mouth disease virus (FMDV), Mycoplasma bovis (M.bovis) and Brucella. The total agreement rate of bELISA with VNT was 93.96 % (249/265). In addition, the result of bELISA was positively correlated with neutralizing antibody titer, and the bELISA could well distinguish the serum samples before and after BVDV vaccination. These results indicate that the established bELISA in this study is specific, sensitive, simple and convenient, which provides technical support for the vaccine efficacy evaluation, prevention and control of BVD in the future.

Bovine Viral Diarrhea Virus Antibody Level Variation in Newborn Calves after Vaccination of Late-Gestational Cows.

This study was conducted to confirm variation in bovine viral diarrhea virus (BVDV) antibody levels transferred to calves from their mother's colostrum after vaccination of late-gestational cows. Blood samples were drawn from 60 pregnant cows that had been vaccinated more than one year and less than two years previously. The samples were collected six weeks prior to the expected date of delivery. After sample collection, the cows were divided into two groups of 30. One group received 2 mL of BVDV vaccine, and a control group received 2 mL of phosphate-buffered saline (PBS). Blood was collected from the cows three weeks post-administration. Additional blood samples were taken from calves at 1, 4, 8, 12, 16, and 20 weeks after birth. The serum was separated from the collected blood, and BVDV antibody changes were confirmed by enzyme-linked immunosorbent assays. BVDV antibody levels were higher from 8 to 20 weeks of age in calves born to late-gestational BVDV-vaccinated cows than in calves born to control cows (p < 0.0083). Further analysis confirmed a slow decline in BVDV maternal antibodies in calves born to pregnant cows that produced high levels of BVDV antibodies following pre-calving BVDV vaccination. These results suggest that BVDV vaccination of cattle in late pregnancy may help to extend the duration of protection against BVDV infection in newborn calves.

The Involvement of Neutrophil in the Immune Dysfunction Associated with BVDV Infection.

Bovine viral diarrhea virus (BVDV) induces immune dysfunction that often results in a secondary bacterial infection in the infected animals. The underlying mechanism of BVDV-induced immune dysfunction is not well understood. The role of BVDV-infected macrophage-secreted factors was investigated. BVDV-infected monocyte-derived macrophage (MDM) supernatants down-regulated the expression of neutrophil L-selectin and CD18. Regardless of the biotype, phagocytic activity and oxidative burst were downregulated by BVDV-infected MDM supernatants. However, only supernatants from cytopathic (cp) BVDV down-regulated nitric oxide production and neutrophil extracellular traps (NET) induction. Our data suggested that BVDV-induced macrophage-secreted factors caused immune dysfunction in neutrophils. Unlike lymphocyte depletion, the negative impact on neutrophils seems to be specific to cp BVDV biotype. Interestingly the majority of modified live BVDV vaccines are based on cp strain of BVDV.

Risk analysis of bovine viral diarrhea in Kazakhstan

Bovine viral diarrhea (BVD) is an acute infectious disease caused by BVD virus (BVDV). BVD is characterized by fever, lesions of the mucosal lining of the digestive tract, diarrhea, conjunctivitis and rhinitis. This disease is considered as one of the most dangerous infectious diseases in animal husbandry worldwide because of its high prevalence, persistence in the environment, and severe clinical consequences. The purpose of this study is to assess the epizootological situation on BVD of cattle, which has developed by the beginning of 2021 in various regions of the Republic of Kazakhstan.&nbsp; For this purpose, we retrospectively analyzed samples of cattle serum collected in 2018-2020 by ELISA for the presence of antibodies to BVDV in them. It was found that BVD in cattle was prevalent even before 2021 in a significant area of Kazakhstan, while the total seroprevalence for BVDV was 67.3% (243/361; 95% CI: 0.37-0.63). Among the animals from which serum was taken, 51.2% of the animals were vaccinated with BVDV vaccines and 48.8% of the animals were unvaccinated. The average seroprevalence of antibodies to BVDV in unvaccinated animals was 36.4% (64/176; 95% CI: 1.2-2.5) positive samples were detected in unvaccinated animals in Zerenda, Astrakhan, Tselinograd and Shortanda districts of Akmola region, also in Akzhar and Kyzylzhar districts of North Kazakhstan region and Aksu district of Almaty region. The results obtained contribute to the disclosure of the epizootological situation of BVD in the territory of Kazakhstan, which will allow the full use of effective control measures, such as total vaccination of livestock in the risky regions of the infection and the introduction of strict restrictive measures to prevent further spread of the infection to other regions of the country. Keywords: Bovine viral diarrhea, cattle, enzyme immunoassay, Pestivirus, Togaviridae.

Novel bovine viral diarrhea virus (BVDV) virus-like particle vaccine candidates presenting the E2 protein using the SpyTag/SpyCatcher system induce a robust neutralizing antibody response in mice.

Bovine viral diarrhea virus (BVDV) is a pathogen of commercial consequence in cattle. Although many modified live and killed vaccines are commercially available, their drawbacks precipitate the need for new effective vaccines. Virus-like particles (VLPs) are a safe and powerful technology used in several human and veterinary vaccines; however, it is difficult to produce large amounts of BVDV VLPs. In this study, we generated red-spotted grouper nervous necrosis virus (RGNNV) VLPs presenting the BVDV E2 protein (domain I to IIIb) of the Nose (BVDV-1) or KZ-91-CP (BVDV-2) strain by exploiting SpyTag/SpyCatcher technology. Mice immunized twice with 30 μg of RGNNV VLPs conjugated with 10 μg of E2 proteins of the Nose or KZ-91-CP strain with a 14-day interval elicited high (1:512,000 to 1:1,024,000) and moderate (1:25,600 to 1:102,400) IgG titers against E2 proteins of homologous and heterologous strains, respectively. In addition, this prime-boost regimen induced strong (1:800 to 1:3,200) and weak (~1:10) neutralization titers against homologous and heterologous BVDV strains, respectively. Our results indicate that conjugation of the E2 protein to RGNNV VLPs strongly enhances the antigenicity of the E2 protein and that RGNNV VLPs presenting the E2 protein are promising BVDV vaccine candidates.

Sero-Epidemiology and Evaluation of First Self-Prepared Bovine Viral Diarrhea Virus Vaccine in Cattle of Punjab, Pakistan

Sero-Epidemiology and Evaluation of First Self-Prepared Bovine Viral Diarrhea Virus Vaccine in Cattle of Punjab, Pakistan

44 Evaluation of Prenatal Transportation Stress on Humoral and Cell-Mediated Immunity After Modified-Live Viral BVDV Vaccination in Brahman Calves

Abstract The objective of this study was to evaluate whether prenatal transportation stress (PNS) affects the immune response of Brahman calves after vaccination against Bovine Viral Diarrhea Virus (BVDV). Mature Brahman cows inseminated to a single Brahman sire in 2018 were assigned to either Control (n=35; not transported) or PNS (n=37; 2h of transportation at 60, 80, 100, 120, and 140±5 d of gestation). Of the calves born in 2019, 11 Control and 12 PNS calves were studied for vaccine treatment (VAX). Temperament score, body weight, and blood samples were obtained from calves prior to weaning (D-28), prior to first BoviShield vaccine (D+35), and after second BoviShield vaccine (D+98). Serum cortisol was determined by RIA. Humoral immune response was evaluated by virus neutralization (VN) assays using serum collected at respective timepoints post-vaccination. Cell-mediated immune (CMI) response was evaluated using a novel PrimeFlow RNA assay that incorporates cell surface marker staining with intracellular RNA expression of cytokines on blood samples obtained at D+35 and D+98. Data were analyzed using GLM procedures of SAS. Only total WBC and absolute lymphocytes were increased with PNS (P&amp;lt; 0.05), while lymphocytes were also decreased with VAX (P&amp;lt; 0.05). There was no PNS effect on the VN or CMI results, serum cortisol concentration, or temperament score. VAX tended (P=0.06) to reduce serum cortisol, as well as resulted in an increase in VN titers (P&amp;lt; 0.01) and frequency of interferon-γ mRNA expression in the CD4+ population (P&amp;lt; 0.01), but not in CD25+ population (P=0.26). Interaction between sampling day and VAX resulted in more drastic increase (P&amp;lt; 0.05) from D+35 to D+98 in VN titers, CD4+ population frequency of interferon-γ mRNA expression, and CD25+ population mean fluorescent intensity. Vaccine treatment positively affected humoral and cell-mediated immune responses; however prenatal transportation stress did not negatively impact response of Brahman calves to immunization against BVDV.

Three cases of alloimmune mediated pancytopenia in calves resembling bovine neonatal pancytopenia

BackgroundBetween 2007 and 2011 several thousands of calves died from bovine neonatal pancytopenia (BNP), a bleeding syndrome triggered by vaccine induced alloantibodies from the dams. Following withdrawal of the involved bovine viral diarrhoea virus (BVDv) vaccine, the incidence of this condition rapidly decreased, with no reported cases in the last 5 years. Here, we report a recent immune-mediated pancytopenia in three calves from two different suckler herds, clinically indistinguishable from BNP.Case presentationThree Belgian Blue suckler calves from two different farms, aged around two weeks, showed multiple bleedings disseminated on the skin and petechiae and ecchymoses on the mucosae. Blood examination confirmed anaemia, leukopenia and thrombocytopenia. BVDv infection was excluded. Despite blood transfusion and cortisone therapy, all three animals died. Necropsy and histology confirmed bone marrow depletion. Binding of IgG from the dams on leukocytes of the calves was demonstrated by flow cytometry. Two calves, originating from the same farm, received colostrum from the same dam. None of the calves were given colostrum replacers or colostrum supplements. No link with the BNP causing BVDv vaccine could be evidenced. However, dams had been vaccinated against bovine herpesvirus 1, parainfluenza-3 virus, bovine respiratory syncytial virus and bluetongue virus serotype 8.ConclusionsAlloimmune mediated pancytopenia was evidenced in three animals, clinically and pathologically indistinguishable from BNP. Whether this disease is again vaccine mediated remains to be determined.

Modern Advances on the Diagnosis of Bovine Viral Diarrhoea Virus In Camelids

Bovine viral diarrhoea virus (BVDV) is one of the most leading causes of diarrhoea in many species of animals including camelids. Special attention is being paid to studying various aspects of the BVDV infection, pathogenesis, epidemiology, diagnosis and vaccines in the bovine species. Little is still known about these aspects in camelids especially dromedaries. The development of accurate diagnostic tests is a critical step for the identifcation of infected animals, especially persistently infected and for the control and eradication of BVDV. Although adaptation of the currently used diagnostic assays for the virus in the bovine and ovine species for the diagnosis of BVDV in the camelids, it is highly recommended to develop novel specifc diagnostic assays of the virus in camels. There are several strategies for the diagnosis of BVDV including virus isolation, detection of viral (antigens, antibodies and nucleic acids) and identifcation of the circulating strains of the virus by doing sequencing and phylogenetic analysis. Identifcation of the persistently infected animals is one of the main challenges facing the diagnosis and control of the virus. Our main objectives are to highlight the most recent advances in the feld of BVDV diagnosis, currently used diagnostic assays and suggested some specifc approaches for the diagnosis of BVDV in camelids. Fine-tuning the currently used diagnostic assays and development of other novel specifc assays to detect BVDV infection in dromedary camels will have a substantial positive impact on the control of BVDV infections in camels.

Seroprevalence and risk factors of Neospora caninum and Bovine Viral Diarrhoea Virus in smallholder dairy cattle in Kenya

Little is known of the risk factors associated with occurrence of Neospora caninum and Bovine Viral Diarrhoea Virus (BVDV) infection in Kenya. This cross-sectional study hypothesized that there are significant biosecurity measures associated with N. caninum and BVDV infections on smallholder dairy farms in Kenya that could be adopted to reduce seroprevalence and impacts. From 158 randomly selected farms in Meru County, Kenya, 470 serum samples were collected from dairy cattle (over six months of age and unvaccinated for these two pathogens). Sera were analyzed for antibodies to N. caninum and antibodies and antigens to BVDV. Data on risk factors were obtained through face-to-face interviews with the farmers. Multivariable logistic regression models were used to identify significant risk factors associated with seropositivity for the pathogens. The apparent seroprevalence of N. caninum, BVDV antibody, BVDV antigen, and co-infection with N. caninum and BVDV antibody and/or antigen were 35.1%, 47.1%, 36.2% and 18.5%, respectively. Risk factors associated with N. caninum antibody included: introducing milking cows into the farm, lending of cattle between farms, farm dogs having access to bovine aborted fetuses, and dogs whelping in the farm compound, with an interaction between the last two variables. BVDV antigen was associated with cattle having contact with pigs, and an interaction between cattle age and whether farms introduced new calves onto farms, and cattle age and whether visiting dairy farmers have access to the cow shed. Cows had higher odds of having BVDV antibodies compared to heifers. Factors associated with co-infection included cow parity, direct contact between dairy cattle, dogs and goats, and introducing new milking cows into the farms. Antibody and antigen results may be partly a function of classical swine fever virus or border disease virus interactions. Farmer education on these biosecurity measures is recommended, along with introduction of BVDV vaccination.

Use of multivariate analysis to evaluate antigenic relationships between US BVDV vaccine strains and non-US genetically divergent isolates

Bovine viral diarrhea virus (BVDV) comprises two species, BVDV-1 and BVDV-2. But given the genetic diversity among pestiviruses, at least 22 subgenotypes are described for BVDV-1 and 3-4 for BVDV-2. Genetic characterization is generally accomplished through complete or partial sequencing and phylogeny, but it is not a reliable method to define antigenic relationships. The traditional method for evaluating antigenic relationships between pestivirus isolates is the virus neutralization (VN) assay, but interpretation of the data to define antigenic relatedness can be difficult to discern for BVDV isolates within the same BVDV species. Data from this study utilized a multivariate analysis for visualization of VN results to analyze the antigenic relationships between US vaccine strains and field isolates from Switzerland, Italy, Brazil, and the UK. Polyclonal sera were generated against six BVDV strains currently contained in vaccine formulations, and each serum was used in VNs to measure the titers against seven vaccine strains (including the six homologous strains) and 23 BVDV field isolates. Principal component analysis (PCA) was performed using VN titers, and results were interpreted from PCA clustering within the PCA dendrogram and scatter plot. The results demonstrated clustering patterns among various isolates suggesting antigenic relatedness. As expected, the BVDV-1 and BVDV-2 isolates did not cluster together and had the greatest spatial distribution. Notably, a number of clusters representing antigenically related BVDV-1 subgroups contain isolates of different subgenotypes. The multivariate analysis may be a method to better characterize antigenic relationships among BVDV isolates that belong to the same BVDV species and do not have distinct antigenic differences. This might be an invaluable tool to ameliorate the composition of current vaccines, which might well be important for the success of any BVDV control program that includes vaccination in its scheme.

Vaccination of Sheep with Bovine Viral Diarrhea Vaccines Does Not Protect against Fetal Infection after Challenge of Pregnant Ewes with Border Disease Virus.

Border Disease (BD) is a major sheep disease characterized by immunosuppression, congenital disorders, abortion, and birth of lambs persistently infected (PI) by Border Disease Virus (BDV). Control measures are based on the elimination of PI lambs, biosecurity, and frequent vaccination which aims to prevent fetal infection and birth of PI. As there are no vaccines against BDV, farmers use vaccines directed against the related Bovine Viral Diarrhea Virus (BVDV). To date, there is no published evidence of cross-effectiveness of BVDV vaccination against BDV infection in sheep. We tested three commonly used BVDV vaccines, at half the dose used in cattle, for their efficacy of protection against a BDV challenge of ewes at 52 days of gestation. Vaccination limits the duration of virus-induced leukopenia after challenge, suggesting partial protection in transient infection. Despite the presence of BDV neutralizing antibodies in vaccinated ewes on the day of the challenge, fetuses of vaccinated and unvaccinated sheep were, two months after, highly positive for BDV RNA loads and seronegative for antibodies. Therefore, BVDV vaccination at half dose was not sufficient to prevent ovine fetal infection by BDV in a severe challenge model and can only be reconsidered as a complementary mean in BD control.

Recent Advances on the Bovine Viral Diarrhea Virus Molecular Pathogenesis, Immune Response, and Vaccines Development.

The bovine viral diarrhea virus (BVDV) consists of two species and various subspecies of closely related viruses of varying antigenicity, cytopathology, and virulence-induced pathogenesis. Despite the great ongoing efforts to control and prevent BVDV outbreaks and the emergence of new variants, outbreaks still reported throughout the world. In this review, we are focusing on the molecular biology of BVDV, its molecular pathogenesis, and the immune response of the host against the viral infection. Special attention was paid to discuss some immune evasion strategies adopted by the BVDV to hijack the host immune system to ensure the success of virus replication. Vaccination is one of the main strategies for prophylaxis and contributes to the control and eradication of many viral diseases including BVDV. We discussed the recent advances of various types of currently available classical and modern BVDV vaccines. However, with the emergence of new strains and variants of the virus, it is urgent to find some other novel targets for BVDV vaccines that may overcome the drawbacks of some of the currently used vaccines. Effective vaccination strategy mainly based on the preparation of vaccines from the homologous circulating strains. The BVDV-E2 protein plays important role in viral infection and pathogenesis. We mapped some important potential neutralizing epitopes among some BVDV genomes especially the E2 protein. These novel epitopes could be promising targets against the currently circulating strains of BVDV. More research is needed to further explore the actual roles of these epitopes as novel targets for the development of novel vaccines against BVDV. These potential vaccines may contribute to the global eradication campaign of the BVDV.

Novel potent IFN-γ-inducing CD8+ T cell epitopes conserved among diverse Bovine Viral Diarrhea Virus strains

Abstract Studies of immune responses elicited by Bovine Viral Diarrhea Virus (BVDV) vaccines have primarily focused on the characterization of neutralizing B cell and CD4+ T cell epitopes. Despite availability of vaccines for decades, BVDV prevalence in cattle remains largely unaffected. There is limited knowledge regarding the role of BVDV-specific CD8+ T cells in immune protection and indirect evidence suggests that they play a crucial role during BVDV infection. In this study, presence of BVDV-specific CD8+ T cells that are highly cross-reactive in cattle was demonstrated. Most importantly, novel potent IFN-γ-inducing CD8+ T cell epitopes were identified from different regions of BVDV polyprotein. Eight CD8+ T cell epitopes were identified from structural BVDV antigens: Erns, E1, and E2 glycoproteins. In addition, from nonstructural BVDV antigens: Npro, NS2-3, NS4A-B, and NS5A-B, twenty CD8+ T cell epitopes were identified. Majority of these IFN-γ-inducing CD8+ T cell epitopes were found to be highly conserved among more than two hundred strains from BVDV-1 and -2 genotypes. These conserved epitopes were also validated as cross-reactive since they induced high recall IFN-γ+ CD8+ T cell responses, ex vivo, in purified CD8+ T cells from BVDV-1- and -2-immunized cattle. Altogether, twenty-eight bovine MHC I-binding epitopes were identified from key BVDV antigens that can elicit broadly reactive CD8+ T cells against diverse BVDV strains. The data presented here will lay the groundwork for the development of a contemporary CD8+ T cell-based BVDV vaccine capable of addressing BVDV heterogeneity more effectively than current vaccines.

Novel Potent IFN-γ-Inducing CD8+ T Cell Epitopes Conserved among Diverse Bovine Viral Diarrhea Virus Strains.

Studies of immune responses elicited by bovine viral diarrhea virus (BVDV) vaccines have primarily focused on the characterization of neutralizing B cell and CD4+ T cell epitopes. Despite the availability of commercial vaccines for decades, BVDV prevalence in cattle has remained largely unaffected. There is limited knowledge regarding the role of BVDV-specific CD8+ T cells in immune protection, and indirect evidence suggests that they play a crucial role during BVDV infection. In this study, the presence of BVDV-specific CD8+ T cells that are highly cross-reactive in cattle was demonstrated. Most importantly, novel potent IFN-γ-inducing CD8+ T cell epitopes were identified from different regions of BVDV polyprotein. Eight CD8+ T cell epitopes were identified from the following structural BVDV Ags: Erns, E1, and E2 glycoproteins. In addition, from nonstructural BVDV Ags Npro, NS2-3, NS4A-B, and NS5A-B, 20 CD8+ T cell epitopes were identified. The majority of these IFN-γ-inducing CD8+ T cell epitopes were found to be highly conserved among more than 200 strains from BVDV-1 and -2 genotypes. These conserved epitopes were also validated as cross-reactive because they induced high recall IFN-γ+CD8+ T cell responses ex vivo in purified bovine CD8+ T cells isolated from BVDV-1- and -2-immunized cattle. Altogether, 28 bovine MHC class I-binding epitopes were identified from key BVDV Ags that can elicit broadly reactive CD8+ T cells against diverse BVDV strains. The data presented in this study will lay the groundwork for the development of a contemporary CD8+ T cell-based BVDV vaccine capable of addressing BVDV heterogeneity more effectively than current vaccines.

A novel MHC-II targeted BVDV subunit vaccine induces a neutralizing immunological response in guinea pigs and cattle.

Bovine viral diarrhoea virus (BVDV) is a major cause of economic loss in the cattle industry, worldwide. Infection results in reduced productive performance, growth retardation, reduced milk production and increased susceptibility to other diseases leading to early culling of animals. There are two primary methods used to control the spread of BVDV: the elimination of persistently infected (PI) animals and vaccination. Currently, modified live or inactivated vaccines are used in BVDV vaccination programmes, but there are safety risks or insufficient protection, respectively, with these vaccines. Here, we report the development and efficacy of the first targeted subunit vaccine against BVDV. The core of the vaccine is the fusion of the BVDV structural protein, E2, to a single-chain antibody, APCH, together termed, APCH-E2. The APCH antibody targets the E2 antigen to the major histocompatibility type II molecule (MHC-II) present on antigen-presenting cells. Industrial production of the vaccine is carried out using the baculovirus expression vector system (BEVS) using single-use manufacturing technologies. This new subunit vaccine induces strong BVDV-specific neutralizing antibodies in guinea pigs and cattle. Importantly, in cattle with low levels of natural BVDV-specific neutralizing antibodies, the vaccine induced strong neutralizing antibody levels to above the protective threshold, as determined by a competition ELISA. The APCH-E2 vaccine induced a rapid and sustained neutralizing antibody response compared with a conventional vaccine in cattle.

Trails of use of nano-particles as adjuvant for inactivated bovine viral diarrheoa vaccine

Bovine viral diarrhea virus (BVDV) with different genotypes considered as one of the most important viruses in genus Pestivirus at animal level is consider an ideal research model for hepatitis C virus of the same genus of Flavivirus. Many traditional inactivated BVDV vaccine have been used adjuvanted by Alhydragel or oil. The current study focused on formulation anew inactivated BVDV vaccine using innovated nano material (meso porous nano silica) prepared with as 9 parts of viral suspension: 1- Part of dissolved adjuvant. Sterility and safety of the adjuvant alone and with the prepared vaccine containing two genotypes of BVDV (1and 2) and potency test on in vaccinated calves revealed that such adjuvant and vaccine are free from foreign contaminants and the vaccine is potent provided calves with protection against BVDV coverage a period of 9 month for both genotypes using two doses of 1.5mL of both inactivated virus vaccine. This study recommended other complementary study to clarify the detail keeping quality issues and field study.