Foot-and-mouth Disease Vaccine Research Articles

Development of a double-antibody sandwich ELISA for rapidly quantitative detection of residual non-structural proteins in inactivated foot-and-mouth disease virus vaccines

Foot-and-mouth disease (FMD) is a highly contagious and economically devastating disease of cloven-hoofed animals. Vaccination and surveillance against non-structure protein (NSP) are the most efficacious and cost-effective strategy to control this disease. Therefore, vaccine purity control is vital for successful prevention. Currently, vaccine purity is tested by an in-vivo test that recommended in the World Organization for Animal Health (WOAH), but it is time consuming and costly. Herein, we develop a double-antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) for quantitative detection of residual NSPs in inactivated FMD virus (FMDV) vaccines. In this assay, the monoclonal antibody 3A24 was selected as capture antibody and biotinylated 3B4B1 (Biotin-3B4B1) as detection antibody. A standard curve was developed using the NSP 3AB concentration versus OD value with the linear range of concentration of 2.5–160 ng/mL. The lowest limit of detection was 2.5 ng/mL. In addition, we determined 2.5 ng/mL of NSP as an acceptable threshold value of FMD vaccine purity using a dose-response experiment in cattle. The DAS-ELISA combined with the threshold value of FMD vaccine purity could provide a quick and simple tool for evaluation the antigenic purity of FMD vaccine during the manufacturing process.

Effect of oestrus synchronisation through ovulation delay by vaccination against foot-and-mouth disease in Hanwoo (Bos taurus coreanae) cows.

In Korean cattle, after foot-and-mouth disease (FMD) vaccination, anovulation increases, acute immune response is stimulated. Here, we aimed to improve the fertility rate by ovulation delay caused by the foot-and-mouth disease vaccine. 160 cows (control, FMD, FMD+Gn250 and FMD+Gn500 groups, with 40 cows each) were used. We analysed the ovulation delay, ovulation rate, conception rate and acute-phase immune responses. In the group vaccinated only with FMD, the average follicle size was maintained at 12mm and ovulation was delayed. The ovulation rate of the FMD+Gn500 group (500μg gonadotropin-releasing hormone (GnRH) injections 3 days after the FMD vaccination) was the highest at 81.8%. The ovulation rate of the FMD+Gn250 group (250μg GnRH injections 3 days after FMD vaccination) was 54.5%, and that of the control group (not FMD vaccinated) was 53.3%. The conception rate was 52.5% (19/40) in the control group, 37.5% (15/40) in the FMD+Gn250 group, and 67.5% (27/40) in the FMD+Gn500 group. Analysis of acute-phase immune response revealed that the plasma contents of haptoglobin and serum amyloid A increased up to 7 days after vaccination against FMD in all the experimental groups, except the control group. We concluded that ovulation delay can be employed to improve conception rate after FMD vaccination through a modified ovulation synchronisation method with GnRH.

ADAPTATION OF FOOT & MOUTH DISEASE VIRUS SUBTYPES PAN ASIA-II, TUR-06 AND SINDH-08 TOWARDS THE VACCINE DEVELOPMENT AND SEROLOGICAL FINDINGS BY SPC ELISA AND SERUM NEUTRALIZATION TEST

FMD serotype “O” with subtype PAN Asia-II, serotype “A” with subtype Tur-06 and serotype “Asia-1” with subtype Sindh-08 were adapted on the LFBK cell line and subsequently on BHK-21. After inactivation these subtypes were introduced for the development of oil based trivalent vaccine against FMD. The study was conducted on the experimental animals (cow calves) at Livestock Production Research Institute (LPRI), Okara. Twenty one unvaccinated cattle calves of age group 4-6 month were used in the study, 16 were injected with experimentally prepared oil based FMD vaccine at the dose rate of 2cc per cow calf at day 0 and 28 post priming while five cattle calves were kept as control. The FMD oil based vaccine containing subtypes PAN ASIA-II, TUR-06 and SINDH-08 showed satisfactory immune response on ELISA and Serum Neutralization Test (SNT) at day 28 post priming and day 28 post booster. The study aimed to strengthen the national control strategy against FMD by the incorporation of prevalent field strains of FMD virus for the vaccine development.

Ultrasound monitoring of the regenerative treatment of Biceps Tendonitis and Tenosynovitis in dogs by stem cells injections

Foot-and-mouth disease (FMD) and bluetongue disease (BT) are two of the most devastating viral diseases affecting domestic and wild ruminants. They cause significant economic losses, and vaccination is the most important method for combating both FMD and BT. Simultaneous vaccinations are crucial for animal welfare as well as labor and cost savings. No reports were found on the simultaneous administration of FMD and BT vaccines to sheep. This study evaluated the effect of the simultaneous administration of an inactivated FMD vaccine and an attenuated BT vaccine on the humoral immune response to both diseases. A total of 75 sixmonth- old Akkaraman-Kıvırcık crossbred sheep that did not have any vaccination history were used as research material. Before the experiment, the animals were tested for the absence of FMD and BT antibodies. The sheep were divided into three experimental groups and vaccinated with an FMD vaccine alone, a BT vaccine alone, and both. Blood samples were taken on days 30 and 60 post-vaccination. The blood samples were evaluated using liquid-phase blocking ELISA (LPBE) and virus neutralization test (VNT) for FMD antibodies, as well as competitive ELISA (c-ELISA) and VNT for BT antibodies. The study revealed that differences between the FMD and BT antibody titers of the group vaccinated simultaneously and the FMD and BT antibody titers obtained from the groups vaccinated separately were not statistically significant (p > 0.05). It was concluded that the antibody response these diseases was not altered when the FMD and BT vaccines were administered together.

Investigation of the effect of mutual vaccination with pest des petits ruminants and polyvalent foot and mouth disease vaccines on the immune response of sheep.

Pest des petits ruminants (PPRs) and foot and mouth disease (FMD) are two viral infectious diseases affecting sheep dramatically causing great economic losses. Therefore, attention should be directed toward their control, especially through the application of well-designed vaccination schedules with specific potent vaccines. Determination of the possibility of sheep vaccination with PPR and FMD vaccines in a mutual schedule. Different groups of sheep have vaccinated with live attenuated PPR vaccine and inactivated polyvalent FMD vaccine in a mutual manner (one before the other at weekly intervals or simultaneously) followed by monitoring of the induced immunity to both vaccines using serum neutralization test (SNT) and enzyme linked immune sorbent assay (ELISA). SNT and ELISA revealed that there was no antagonizing effect of any vaccine on the immune response to the mutual vaccination of sheep to the other where the obtained antibody titers in single vaccinated sheep groups were similar to those in the simultaneous vaccinated group. Simultaneous vaccination of sheep with PPR and polyvalent FMD vaccine is of applicable benefit saving time, effort, and stress factors on the animals.

Expression of FMD virus-like particles in yeast Hansenula polymorpha and immunogenicity of combine with CpG and aluminum adjuvant

Inactivated vaccines are limited in preventing foot-and-mouth disease (FMD) due to safety problems. Recombinant virus-like particles (VLPs) are an excellent candidate for a novel vaccine for preventing FMD, given that VLPs have similar immunogenicity as natural viruses and are replication- and infection-incompetent. The 3C protease and P1 polyprotein of type O FMD virus (FDMV) was expressed in yeast Hansenula polymorpha to generate self-resembling VLPs, and the potential of recombinant VLPs as an FMD vaccine was evaluated. BALB/c mice were immunized with recombinant purified VLPs using CpG oligodeoxynucleotide and aluminum hydroxide gel as an adjuvant. Cytokines and lymphocytes from serum and spleen were analyzed by enzyme-linked immunosorbent assay, enzyme-linked immunospot assay, and flow cytometry. The VLPs of FMD were purified successfully from yeast protein with a diameter of approximately 25 nm. The immunization of mice showed that animals produced high levels of FMDV antibodies and a higher level of antibodies for a longer time. In addition, higher levels of interferon-γ and CD4+ T cells were observed in mice immunized with VLPs. The expression of VLPs of FMD in H. polymorpha provides a novel strategy for the generation of the FMDV vaccine.

Disease Prevalence among Cattle and Knowledge of Farmers Regarding Health Management and Livestock Technology in Developing Countries: Evidence from Bangladesh

This study aims to investigate the prevalence of cattle disease and the knowledge of farmers regarding health management and livestock technology in Bangladesh as a paradigm of developing countries. Data were collected via face-to-face interviews between December 2020 and June 2021 from 301 randomly selected farmers from three districts in Bangladesh. Foot and Mouth (FMD) was the predominant disease in the study cattle. About 45% of cattle in Dhaka and 40% of cattle in Rajshahi were infected with FMD while Diarrhea (33%) and bloat (33%) were most prevalent in cattle from Sirajganj. Although the majority of respondents practiced regular vaccination and deworming for cattle, they had significantly less knowledge of vaccination and deworming. Moreover, there is a significant difference in regular practice and knowledge of farmers about vaccination among our study areas (p<0.007). FMD vaccine use was significantly higher among farmers of Dhaka (p<0.016) while the use of Black quarter (p<0.003) and Hemorrhagic septicemia (p<0.001) vaccines were significantly higher among farmers of Rajshahi. Most of the respondents provided prophylactic care by themselves or with the help of quacks while dependent on quacks or registered veterinarians for treatment. Half of the farmers faced various problems in health care management including the high prevalence of diseases (60%). Fifty-two percent of subjects from Dhaka had received different training such as cattle rearing and animal health and 84% of them implemented received training. The results of this study demonstrated that more awareness and training are needed regarding healthcare management and technology adoption in developing countries like Bangladesh for obtaining sustainable livestock production.

Şap hastalığı (FMD) ve üç gün hastalıklarına (BEF) karşı eş zamanlı aşılanmış sığırlarda bağışıklık yanıt

Bovine ephemeral fever (BEF) virus is an arthropod-borne rhabdovirus and causing an acute febrile illness disease in cattle and water buffalo. Foot-and-mouth disease (FMD) is a highly infectious viral disease of mammals and has a great potential for causing severe economic loss in susceptible cloven-hoofed animals. FMD and BEF vaccines are widely used in countries where both diseases are seen together. This study was carried out to determine the immunological response of cattle simultaneously vaccinated with BEF and FMD vaccines. For this purpose, the cattle were divided into 4 groups in this study as single FMD vaccination group (Group 1; n=10), single BEF vaccination group (Group 2; n=10), BEF+FMD simultaneously vaccinated group (Group 3; n=10) and unvaccinated control group (Group 4; n=10). After the first vaccinations, booster BEF vaccine was applied to the cattle in groups 2 and 3. Although there was no increase in the neutralizing antibody titers against BEF and FMD virus in the blood serums of unvaccinated cattle on the 30th and 60th days of vaccination, There were significant increases in statistically protective neutralizing antibody levels in the vaccinated cattle. As a result, it was demonstrated with this study that BEF and FMD vaccines can be applied simultaneously to combat both diseases in cattle.

Decision tree risk analysis for FMD outbreak prevention in Egyptian feedlots

Foot and Mouth Disease (FMD) is one of the most contagious and economically influential viral diseases on animal health and productivity. Introduction of newly purchased animals to beef farms constitutes a greater risk for the FMD outbreaks in endemic countries. Physical examination of newly purchased animals in live animal markets and/or at the receiving farm, and the timing of preventative FMD vaccination may reduce the risk of FMD outbreaks under endemic conditions. Small (< 50 animals) and medium (50–500 animals) sized beef farms in Egypt constitute more than 60% of the country’s beef industry where protocols for receiving newly purchased animals vary widely between farms. The current risk analysis aimed to build a decision tree model to reduce FMD outbreaks associated with introduction of replacement cattle on Egypt’s medium sized beef farms. Management practices explored were the use of physical examinations and FMD vaccination and their timing for replacements with the goal of reducing losses due to FMD outbreaks. A producer survey revealed that more than 50% of the study herds relied on live animal markets as a source for replacements and reported more FMD outbreaks (P-value=0.09), FMD herd morbidity > 50% (p-value=0.05), and weight loss > 15 kg/animal in FMD clinical cases (P-value=0.01) in comparison to herds that received replacements from other farms, imported, or purchased from small stakeholders. More than 70% of the surveyed farms received replacements ≤ 1year old and reported significantly higher FMD outbreaks (P-value=0.02) in comparison to farms that received older animals. More than 80% of the surveyed farms performed physical examination of newly purchased animals before arrival at their premises. Of the surveyed farms, 73% reported FMD outbreaks with 67% of the outbreaks being reported during the Fall and Winter seasons. The decision tree identified physical examination of newly purchased animals prior to arrival and mixing with a premises beef herd followed by vaccination against FMD upon arrival as the intervention resulting in the lowest probability of FMD outbreak (8.9%). In contrast, herds that did not perform physical examination and delay the FMD vaccination for two or more weeks had the highest probability of FMD outbreaks (33.5%).

Efficacy of a Novel Multiepitope Vaccine Candidate against Foot-and-Mouth Disease Virus Serotype O and A.

Foot-and-mouth disease (FMD) is a highly contagious and economically devastating disease in cloven-hoofed animals. To prevent the spread of FMD virus (FMDV), traditional inactivated vaccines are used to immunize susceptible animals in disease-endemic countries. However, the inactivated FMD vaccine has several limitations, including safety concerns. To overcome these limitations, subunit proteins have been studied as alternative vaccine candidates. In this study, we designed two multiepitope recombinant proteins (OVM and AVM) containing antigenic sites (residue of VP1 132-162 and residue of VP1 192-212) of three topotypes of FMDV serotype O or three topotypes of FMDV serotype A. Each recombinant protein was efficiently expressed in Escherichia coli with high solubility, and the immunogenicity and protective efficacy of the proteins as FMD vaccine candidates were evaluated. The results showed that OVM and AVM emulsified with ISA201 adjuvant induced effective antigen-specific humoral and cell-mediated immune responses and successfully protected mice from O/Jincheon/SKR/2014, O/VET/2013, and A/Malaysia/97 viruses. In addition, intramuscular immunization of pigs with the OVM and AVM emulsified with ISA201 elicited effective levels of neutralizing antibodies to the viruses with homologous epitopes. Importantly, OVM-AVM emulsified with CAvant®SOE-X adjuvant conferred 100% protection against the O/Jincheon/SKR/2014 virus with homologous residues and 75% protection against A/SKR/GP/2018 with heterologous residues. The results presented in this study suggest that the combination of OVM and AVM protein with an effective adjuvant could yield an effective and safe vaccine candidate for the prevention and control of foot-and-mouth disease. In addition, our results provide a vaccine platform that can safely, cost-efficiently, and rapidly generate protective vaccine candidates against diverse FMDVs.

Pemberdayaan Masyarakat Nagari Palangki dalam Mengatasi Penyakit Mulut dan Kuku (PMK)

Nagari Palangki, IV Koto District, Sinjunjung Regency, is one area that has the potential for beef cattle farming and a large livestock market. The Palangki cattle market is the largest cattle market in West Sumatra. The Palangki cattle market has become a supplier of beef cattle for the provinces of West Sumatra, Jambi, Riau and Bengkulu. The operation of the Palangki livestock market was closed due to cattle infected by mouth and nail disease (FMD). FMD is a contagious animal disease that attacks hoofed animals, especially livestock such as cattle, goats and sheep caused by viruses. This disease can cause huge economic losses because it can lead to a decrease in livestock productivity and even death. It is necessary to take action in dealing with FMD, therefore socialization of the handling and prevention of oral and nail diseases is carried out to the Basung Indah Palangki farmer group. FMD vaccination was carried out in collaboration with the Agriculture Service of Sijunjung Regency and 100 cows were vaccinated in District IV Nagari. The activity aimed to empower and provide insight to Nagari Palangki cattle farmers in overcoming oral and nail diseases.

PRAGMATIST: A tool to prioritize foot-and-mouth disease virus antigens held in vaccine banks.

Antigen banks have been established to supply foot-and-mouth disease virus (FMDV) vaccines at short notice to respond to incursions or upsurges in cases of FMDV infection. Multiple vaccine strains are needed to protect against specific FMDV lineages that circulate within six viral serotypes that are unevenly distributed across the world. The optimal selection of distinct antigens held in a bank must carefully balance the desire to cover these risks with the costs of purchasing and maintaining vaccine antigens. PRAGMATIST is a semi-quantitative FMD vaccine strain selection tool combining three strands of evidence: (1) estimates of the risk of incursion from specific areas (source area score); (2) estimates of the relative prevalence of FMD viral lineages in each specific area (lineage distribution score); and (3) effectiveness of each vaccine against specific FMDV lineages based on laboratory vaccine matching tests (vaccine coverage score). The output is a vaccine score, which identifies vaccine strains that best address the threats, and consequently which are the highest priority for inclusion in vaccine antigen banks. In this paper, data used to populate PRAGMATIST are described, including the results from expert elicitations regarding FMD risk and viral lineage circulation, while vaccine coverage data is provided from vaccine matching tests performed at the WRLFMD between 2011 and 2021 (n = 2,150). These data were tailored to working examples for three hypothetical vaccine antigen bank perspectives (Europe, North America, and Australia). The results highlight the variation in the vaccine antigens required for storage in these different regions, dependent on risk. While the tool outputs are largely robust to uncertainty in the input parameters, variation in vaccine coverage score had the most noticeable impact on the estimated risk covered by each vaccine, particularly for vaccines that provide substantial risk coverage across several lineages.

Predicting cross-protection against foot-and-mouth disease virus strains by serology after vaccination.

Serology is widely used to predict whether vaccinated individuals and populations will be protected against infectious diseases, including foot-and-mouth disease (FMD), which affects cloven-hoofed animals. Neutralising antibody titres to FMD challenge viruses correlate to protection against FMD, for vaccinated cattle that are infected with the same strain as in the vaccine (homologous protection). Similar relationships exist for cross-strain protection between different vaccine and challenge viruses, although much less data are available for these heterologous studies. Poor inter-laboratory reproducibility of the virus neutralisation test (VNT) also hampers comparisons between studies. Therefore, day-of-challenge sera (n = 180) were assembled from 13 previous FMD cross-protection experiments for serotypes O (n = 2), A (n = 10), and SAT 2 (n = 1). These were tested by VNT against the challenge viruses at the FMD FAO World Reference Laboratory (WRLFMD) and the titres were compared to challenge outcomes (protected or not). This dataset was combined with equivalent serology and protection data for 61 sera from four cross-protection experiments carried out at WRLFMD for serotypes O (n = 2), A (n = 1), and Asia 1 (n = 1). VNT results and protection outcomes were also analysed for a serotype O cross-protection experiment involving 39 cattle, where the sera were not available for retesting at WRLFMD. Three categories of association between heterologous neutralising antibody titre and heterologous protection were found (Group 1-3). The log10 reciprocal titres associated on average with 75% protection (with 95% credible limits) were: Group 1: 2.46 (2.11-2.97); Group 2: 1.67 (1.49-1.92); Group 3: 1.17 (1.06-1.30). Further cross-protection data are needed to understand the factors that underpin this variability and to develop more robust antibody thresholds. Establishing cut-off serological titres that can be used to score the adequacy of vaccine-induced immunity will facilitate the monitoring and thereby the performance of FMD vaccination in the field.

Foot-and-mouth disease virus: DNA aptamer selection for the 3ABC protein

Foot-and-mouth disease (FMD) is a devastating livestock disease caused by foot-and-mouth disease virus (FMDV), a member of the Picornaviridae family. The 3ABC is a non-structural protein of FMDV, produced during viral replication and absent from inactivated FMD vaccines. Nucleic acid aptamers are DNA or RNA oligonucleotides capable of binding with high specificity and affinity to a molecular target. The aim of this study was to obtain DNA aptamers specific for 3ABC protein with a view of their application in the FMD diagnosis.Aptamers are usually obtained through SELEX (Systematic Evolution of Ligands by EXponential enrichment) procedure. In this study, an aptamer (termed FMDV1) was selected by a variation of this technique called Capillary Electrophoresis SELEX (CE-SELEX). The FMDV1 aptamer showed high binding affinity to the 3ABC protein with Kd value in the nano molar range: 22.69 ± 1.79 nM. The FMDV1 aptamer binding to 3ABC was significantly higher when compared with the BSA protein, used as control, demonstrating its specificity.

Enhancement of intestinal mucosal immunity and immune response to the foot-and-mouth disease vaccine by oral administration of danggui buxue decoction

This study investigated the effect of Danggui Buxue decoction (DBD) on the immunity of an O-type foot-and-mouth disease (FMD) vaccine and intestinal mucosal immunity. SPF KM mice were continuously and orally administered DBD for 5 d and then inoculated with an O-type FMD vaccine. The contents of a specific IgG antibody and its isotypes IgG1, IgG2a, IgG2b, and IgG3 in serum and SIgA in duodenal mucosa were determined by ELISA at 1 and 3 W after the 2nd immunization. qRT-PCR was used to detect mRNA expression levels of IL-4, IL-10, IFN-γ, and IL-33 in the spleen, and mRNA expression levels of J-chain, pIgR, BAFF, APRIL, IL-10, IFN-γ and IL-33 in the duodenum. The results showed that compared with the control group, oral administration of DBD significantly increased levels of the anti-FMD virus (FMDV)-specific antibodies IgG, IgG1, and IgG2a in the serum of O-type FMD vaccine-immunized mice 1 W after the 2nd immunization (P < 0.05), upregulated mRNA expression levels of spleen lymphocyte cytokines IL-4 and IL-33 (P < 0.05), promoted the secretion of SIgA in duodenal mucosa (P < 0.05). The mRNA expression levels of J-chain, pIgR, BAFF, APRIL, IL-10, and IL-33 in duodenal tissues were upregulated (P < 0.05). This study indicates that DBD has a good promotion effect on the O-type FMD vaccine and the potential to be an oral immune booster.

Mutation of FMDV Lpro H138 residue drives viral attenuation in cell culture and in vivo in swine

The foot-and-mouth disease virus (FMDV) leader proteinase (Lpro) is a papain like protease that cleaves the viral polyprotein and several host factors affecting host cell translation and induction of innate immunity. Introduction of Lpro mutations ablating catalytic activity is not tolerated by the virus, however, complete coding sequence deletion or introduction of targeted amino acid substitutions can render viable progeny. In proof-of-concept studies, we have previously identified and characterized FMDV Lpro mutants that are attenuated in cell culture and in animals, while retaining their capacity for inducing a strong adaptive immunity. By using molecular modeling, we have now identified a His residue (H138), that resides outside the substrate binding and catalytic domain, and is highly conserved across serotypes. Mutation of H138 renders possible FMDV variants of reduced virulence in vitro and in vivo. Kinetics studies showed that FMDV A12-LH138L mutant replicates similarly to FMDV A12-wild type (WT) virus in cells that do not offer immune selective pressure, but attenuation is observed upon infection of primary or low passage porcine epithelial cells. Western blot analysis on protein extracts from these cells, revealed that while processing of translation initiation factor eIF-4G was slightly delayed, no degradation of innate sensors or effector molecules such as NF-κB or G3BP2 was observed, and higher levels of interferon (IFN) and IFN-stimulated genes (ISGs) were induced after infection with A12-LH138L as compared to WT FMDV. Consistent with the results in porcine cells, inoculation of swine with this mutant resulted in a mild, or in some cases, no clinical disease but induction of a strong serological adaptive immune response. These results further support previous evidence that Lpro is a reliable target to derive numerous viable FMDV strains that alone or in combination could be exploited for the development of novel FMD vaccine platforms.

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 FeverNil PowderTM as Stress-relieving Agent to Reduce the Side Effects of FMD Vaccination in Pigs

Evaluation of Efficacy of FeverNil PowderTM as Stress-relieving Agent to Reduce the Side Effects of FMD Vaccination in Pigs

Effect of Foot-and-Mouth Disease Virus 2B Viroporin on Expression and Extraction of Mammalian Cell Culture Produced Foot-and-Mouth Disease Virus-like Particles.

To improve the production of foot-and-mouth disease (FMD) molecular vaccines, we sought to understand the effects of the FMD virus (FMDV) 2B viroporin in an experimental, plasmid-based, virus-like particle (VLP) vaccine. Inclusion of the FMDV viroporin 2B into the human Adenovirus 5 vectored FMD vaccine enhanced transgene expression despite independent 2B expression negatively affecting cell viability. Evaluating both wildtype 2B and mutants with disrupted viroporin activity, we confirmed that viroporin activity is detrimental to overall transgene expression when expressed independently. However, the incorporation of 2B into an FMD molecular vaccine construct containing a wildtype FMDV 3C protease, a viral encoded protease responsible for processing structural proteins, resulted in enhancement of transgene expression, validating previous observations. This benefit to transgene expression was negated when using the FMDV 3CL127P mutant, which has reduced processing of host cellular proteins, a reversion resulting from 2B viroporin activity. Inclusion of 2B into VLP production constructs also adversely impacted antigen extraction, a possible side effect of 2B-dependent rearrangement of cellular membranes. These results demonstrate that inclusion of 2B enhanced transgene expression when a wildtype 3C protease is present but was detrimental to transgene expression with the 3CL127P mutant. This has implications for future molecular FMD vaccine constructs, which may utilize mutant FMDV 3C proteases.

Seroprevalence and associated risk factors for foot and mouth disease virus seropositivity in cattle in selected districts of Gamo zone, Southern Ethiopia.

BackgroundFoot and mouth disease (FMD) is a highly contagious viral disease of cloven-hoofed animals, which hampers livestock production and productivity in Ethiopia. This cross-sectional study was conducted from January to December 2021 to estimate the seroprevalence of FMD in cattle and to assess farmers' knowledge about the disease in selected districts of the Gamo zone. Three districts and two kebeles (smallest administrative division) from each district were purposively sampled using a simple random sampling technique to select individual animals from each kebeles. A total of 384 sera samples were collected, and concurrently, 100 farmers were interviewed. The samples were tested for antibodies against nonstructural proteins of the FMD virus using a 3ABC enzyme-linked immunosorbent assay (ELISA). Univariable and multivariable logistic regressions were used to analyze FMD-associated risk factors.ResultThe questionnaire survey result revealed that among the interviewed farmers, 66% of farmers had knowledge about the disease, and 28% of farmers reported having a case of FMD in at least one cattle in their farm in the previous 6 months. The overall seroprevalence of FMD in cattle was 26.8%. The multivariable logistic regression revealed that age, breed, and agroecology had a significant association with seropositivity. Higher seroprevalence (64.57%) was observed in lowland, followed by midland (9.30%) and highland (5.88%). Study animals from lowland areas were 9.26 times more likely to be seropositive (OR = 9.26, CI = 2.22–38.62) for FMD than highland animals. Also, adult animals were 9.01 times (OR = 9.01, CI = 3.18–25.53) more likely to be seropositive for the disease than young animals. The multivariable logistic regression revealed that crossbreeds have an 84.7% (OR = 0.153, CI = 0.028–0.82) lower likelihood to be seropositive to FMD than local breeds.ConclusionThis study result confirms that FMD is highly prevalent in the study area, and farmers' knowledge regarding disease transmission and vaccine availability is minimal. Hence the regional concerned bodies should implement FMD vaccination campaigns and create awareness for smallholder farmers regarding the disease transmission, FMD vaccine schedule, and vaccination importance.