Foot-and-mouth Disease Vaccine Research Articles

Efficacy of a foot-and-mouth disease vaccine against a heterologous SAT1 virus challenge in goats

Goats are susceptible to infection with foot-and-mouth disease virus (FMDV), but their role in the epidemiology of the disease and response to vaccination is poorly understood. In southern Africa, FMDV serotypes Southern African Territories (SAT) 1, 2 and 3 are known to be endemic. In this study, we evaluated the efficacy of a pentavalent FMD vaccine in goats against heterologous challenge with a pool of field SAT1 FMDV. Forty FMD sero-negative goats (6–12 months of age) of mixed sexes were randomly allocated to one of five treatment groups: full cattle dose (2 ml), 1/3rd (0.67 ml), 1/6th (0.33 ml), 1/12th (0.16 ml) or unvaccinated placebo control. Goats were vaccinated with an inactivated pentavalent FMD vaccine containing serotypes SAT1, SAT2 and SAT3 on day 0 and revaccinated at day 20 post vaccination. Thereafter, thirty-four goats were challenged by tongue inoculation at day 41 post-vaccination using 104.57 50% tissue culture infective dose (TCID50) FMDV SAT1 pool. Animals were examined daily and clinical signs were scored. Rectal temperatures were measured daily, with temperatures ≥40 °C defined as fever. Clinical specimens (nasal, oral and rectal swabs) were collected on days 0, 2, 4 and 6 post challenge. Viral shedding was determined using reverse-transcriptase real-time PCR. None of the goats vaccinated with the full cattle dose developed secondary lesions. All vaccinated groups had lower temperatures compared to the unvaccinated controls (P < 0.001). Based on RT-PCR results, goats in the unvaccinated control group shed more virus compared to all groups except for 1/12th (P < 0.05), while goats in the full dose group shed less virus than goats in the 1/12th and the unvaccinated control group (P < 0.05). The results suggest that the 1/3rd (0.67 ml) dose of the vaccine is sufficient to reduce viral shedding after heterologous challenge with a FMDV SAT1 pool.

Enhanced Immune Responses with Serum Proteomic Analysis of Hu Sheep to Foot-and-Mouth Disease Vaccine Emulsified in a Vegetable Oil Adjuvant.

Our previous study demonstrated that a vegetable oil consisting of soybean oil, vitamin E, and ginseng saponins (SO-VE-GS) had an adjuvant effect on a foot-and-mouth disease (FMD) vaccine in a mouse model. The present study was to compare the adjuvant effects of SO-VE-GS and the conventional ISA 206 on an FMD vaccine in Hu sheep. Animals were intramuscularly (i.m.) immunized twice at a 3-week interval with 1 mL of an FMD vaccine adjuvanted with SO-VE-GS (n = 10) or ISA 206 (n = 9). Animals without immunization served as control (n = 10). Blood was sampled prior to vaccination and at 2, 4, 6, and 8 weeks post the booster immunization to detect FMD virus (FMDV)-specific IgG. Blood collected at 8 weeks after the booster was used for the analyses of IgG1 and IgG2, serum neutralizing (SN) antibody, IL-4 and IFN-γ production, and proteomic profiles. The results showed that IgG titers rose above the protection level (1:128) in SO-VE-GS and ISA 206 groups after 2 and 4 weeks post the booster immunization. At 6 weeks post the booster, the ISA 206 group had 1 animal with IgG titer less than 1:128 while all the animals in the SO-VE-GS group retained IgG titers of more than 1:128. At 8 weeks post the booster, 6 of 9 animals had IgG titers less than 1:128 with a protective rate of 33.3% in the ISA 206 group, while only 1 of 10 animals had IgG titer less than 1:128 with a protective rate of 90% in the SO-VE-GS group, with statistical significance. In addition, IgG1, IgG2, SN antibodies, IL-4, and IFN-γ in the SO-VE-GS group were significantly higher than those of the ISA 206 group. Different adjuvant effects of SO-VE-GS and ISA 206 may be explained by the different proteomic profiles in the two groups. There were 39 and 47 differentially expressed proteins (DEPs) identified in SO-VE-GS compared to the control or ISA 206 groups, respectively. In SO-VE-GS vs. control, 3 immune related gene ontology (GO) terms and 8 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were detected, while 2 immune related GO terms and 5 KEGG pathways were found in ISA 206 vs. control. GO and KEGG analyses indicated that ‘positive regulation of cytokine secretion’, ‘Th1/Th2 cell differentiation’, and ‘Toll-like receptor signaling pathways’, were obviously enriched in the SO-VE-GS group compared to the other groups. Coupled with protein–protein interaction (PPI) analysis, we found that B7TJ15 (MAPK14) was a key DEP for SO-VE-GS to activate the immune responses in Hu sheep. Therefore, SO-VE-GS might be a promising adjuvant for an FMD vaccine in Hu sheep.

Determination of Risk Factors Associated with Foot and Mouth Disease Outbreaks in Dairy Farms in Chiang Mai Province, Northern Thailand.

Simple SummaryOne hundred and 40 dairy farms that experienced foot and mouth disease (FMD) outbreaks and 307 farms without FMD outbreaks were investigated in this research study. Relevant farm owners were interviewed in order to determine the farm-level risk factors associated with the FMD outbreaks. We established that the risk factors for FMD outbreaks were (1) purchasing a new cow without following quarantine protocol, (2) FMD vaccination administration by non-official livestock personnel, (3) farms located within a 5 km radius of cattle abattoirs, (4) farms located near shared cattle grazing areas in a 10 km radius and (5) no history of FMD outbreaks in the previous year. Most of the risk factors were related to indirect transmissions of FMD and biosecurity practices, thus we have advised dairy farmers to strengthen management practices associated with FMD prevention protocols.Foot and mouth disease (FMD) is considered a highly contagious transboundary disease of cloven-hoofed animals. FMD has become endemic to northern Thailand over the past decade. In 2016, FMD outbreaks were recorded in three districts in Chiang Mai Province. The objective of this study was to determine the farm-level risk factors associated with FMD outbreaks. This study was conducted via a face-to-face interview questionnaire survey at 140 FMD outbreak farms and 307 control farms. Univariable and multivariable logistic regression analyses were used to determine the association between potential risk factors and FMD outbreaks. The final logistic regression model identified factors associated with FMD outbreaks including the purchasing of a new cow without following quarantine protocol (odds ratio = 2.41, 95%CI = 1.45, 4.05), farms located near shared cattle grazing areas in a 10 km radius (OR = 1.83, 95%CI =1.11, 3.02), FMD vaccination administration by non-official livestock personnel (OR = 2.52, 95%CI = 1.39, 4.58), farms located in a 5 km radius of cattle abattoirs (OR = 1.83, 95%CI = 0.99, 3.40) and no history of FMD outbreaks over the previous 12 months in districts where farms were located (OR = 0.44, 95%CI = 0.22, 0.86). The risk factors identified in this study were related to farm biosecurity, FMD vaccination administration and distance from the farms to risk areas. Therefore, it was important to strengthen on-farm biosecurity and to improve farm management practices in order to reduce incidences of FMD at the farm level. Education or training programs for dairy farmers that would enhance knowledge and practices in relation to the assessed topics are needed.

The Effect of Used Immunostimulating Drugs with FMD Vaccine on Immunoglobulins in Sheep

In this study, the effect of used immunostimulating drugs with FMD vaccine on immunoglobulins was aimed to investigate in sheep. For this purpose 40 healthy sheep were divided into 4 groups. Blood and serum samples were taken from all animals from 0 days before the study. Blood samples were measured immediately, and IgA, IgG, IgM, IgE and Zn values from biochemical parameters were stored for measurement. Group I was applied only FMD vaccine, group II Levamisole with the FMD vaccine, group III Zinc with FMD vaccine and the last group IV AD3E was applied with FMD vaccine. After 21 days, blood and serum samples from all groups were taken again and hematologic and IgA, IgG, IgM, IgE and Zn values were compared according to the values of day 0. No statistical difference was found between the groups except for PLT in hematological parameters (p&amp;gt; 0, 05) when compared to pre-vaccination and post-vaccination. In groups II and III there was a significant increase in PLT levels. Biochemical analysis showed IgA, IgG, IgM and IgE levels to be higher in IgG (p &amp;lt;0, 05) and IgE (p &amp;lt;0,001) in groups II and III when levels compared to before vaccination. There were statistically significant increases in IgM (p &amp;lt;0.05) in group IV.

Standardized Plant Extract Alleviates the Negative Effects of FMD Vaccination on Animal Performance.

Simple SummaryFoot and Mouth Disease (FMD) is among the viral diseases causing poor growth performance and reduced immune status, leading to heavy economic losses in livestock. The vaccination of animals against FMD may lead to vaccination stress, thereby reducing the growth performance of animals. The growth promoting effects of a plant extract (consisting of capsicum and turmeric oleoresins) against FMD vaccinated growing pigs are evaluated in the present study. It was determined that the supplementation of the plant extract significantly improved performance and increased the antibody titer against FMD antigens. However, the immune parameters measured at days 10, 15, 20 and 25 post-FMD vaccination remained unaffected.The present study was conducted to assess the efficacy of a plant extract (PE) on growth performance and immune status in foot and mouth disease (FMD)-vaccinated growing pigs. A total of 120 crossed ((Landrace × Yorkshire) × Duroc) growing pigs with an average initial body weight (BW) of 24.66 ± 2.34 kg and an average age of 70 days were randomized into three groups (10 pens; 4 pigs per pen per treatment) as follows: a nonvaccinated negative control group (NV), a FMD vaccinated group (OV), and a third group received a 0.0125% PE supplement after vaccination (PV), in a 6-week trial. The PV group receiving PE supplementation increased (p < 0.05) the BW compared with the OV group, and average daily gain (ADG) during days 1–14, overall and gain-to-feed ratio (G: F) in days 1–14, and dry matter (DM) digestibility at week 6 were higher (p < 0.05) in the PV compared with the OV group. A significant increase (p < 0.05) in haptoglobin concentration was observed in the OV group compared with the NV group at 25 days postvaccination. The inhibition percentage of antibodies against FMD in the sera reached above 50% in the PV group 5 days earlier than in the OV group. The findings suggest that the inclusion of PE in the diet promoted the performance of vaccinated growing pigs.

Serological response against foot-and-mouth disease virus to FMD-haemorrhagic septicaemia-black quarter combined vaccine and FMD vaccine alone in sheep and goat

Foot-and-mouth disease is subclinical in small ruminants and they may play role in spread of disease. Presently, they are not included in vaccination coverage in India under FMD-control programme. A total of 43 animals including sheep (16) and goat (27) were used for vaccination study by combined vaccine (FMD, HS and BQ) and FMD vaccine alone. Humoral immune response was evaluated by monitoring serum antibody titres against FMDV serotypes O, A and Asia 1 on 30, 60, 90 dpv. In both vaccinated groups, peak antibody titre for all 3 serotypes was obtained on 30 dpv, it remained constant up to day 60 and after that there was gradual decrease at 90 dpv. As in both groups there was no significant difference and protective titre remained upto 90 dpv, use of combined vaccine can be suggested as cost effective strategy.

Evaluation of Quality Control Methods for Foot-And-Mouth Disease Vaccines by High-Performance Liquid Chromatography.

Foot-and-mouth disease (FMD) is considered one of the highly contagious viral infections affecting livestock. In Korea, an FMD vaccination policy has been implemented nationwide since 2010 for the prevention and control of FMD. Since the vaccines are imported from various countries, standardized quality control measures are critical. In this study, we aimed to validate a high-performance liquid chromatography (HPLC) device in the Animal and Plant Quarantine Agency lab and identify an appropriate FMD vaccine pretreatment method for HPLC—a simple, reliable, and practical method to measure antigen content. Based on the analyses of specificity, linearity, accuracy, repeatability, intermediate precision, limits of detection, and limits of quantification using FMD standard samples, we validated the method using a standard material. Overall, we confirmed that the HPLC technique is effective for the quantitative assessment of the FMD virus 146S antigen in Korea. Using commercial FMD vaccines, we evaluated three separation methods and identified the method using n-pentanol and trichloroethylene as optimal for HPLC analysis. Our HPLC method was effective for the analytical detection of the antigen content in FMD vaccine, and it may be useful as a reference method for national lot-release testing.

Foot-and-Mouth Disease Virus Lacking the Leader Protein and Containing Two Negative DIVA Markers (FMDV LL3B3D A24) Is Highly Attenuated in Pigs.

Inactivated whole-virus vaccines are widely used for the control of foot-and-mouth disease (FMD). Their production requires the growth of large quantities of virulent FMD virus in biocontainment facilities, which is expensive and carries the risk of an inadvertent release of virus. Attenuated recombinant viruses lacking the leader protease coding region have been proposed as a safer alternative for the production of inactivated FMD vaccines (Uddowla et al., 2012, J Virol 86:11675-85). In addition to the leader deletion, the marker vaccine virus FMDV LL3BPVKV3DYR A24 encodes amino acid substitutions in the viral proteins 3B and 3D that allow the differentiation of infected from vaccinated animals and has been previously shown to be effective in cattle and pigs. In the present study, two groups of six pigs each were inoculated with live FMDV LL3BPVKV3DYR A24 virus either intradermally into the heel bulb (IDHB) or by intra-oropharyngeal (IOP) deposition. The animals were observed for 3 or 5 days after inoculation, respectively. Serum, oral and nasal swabs were collected daily and a thorough postmortem examination with tissue collection was performed at the end of the experiment. None of the animals had any signs of disease or virus shedding. Virus was reisolated from only one serum sample (IDHB group, sample taken on day 1) and one piece of heel bulb skin from the inoculation site of another animal (IDHB group, necropsy on day 3), confirming that FMDV LL3BPVKV3DYR A24 is highly attenuated in pigs.

Comparison of immune responses in guinea pigs by intranasal delivery with different nanoparticles-loaded FMDV DNA vaccine

To compare different nanoparticle-based nasal vaccines against foot-and-mouth disease (FMD), chitosan (CS)-coated poly (lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) (CS/PLGA-NPs) and amino-functionalized mesoporous silica nanoparticles (Am/MSNs) loaded with FMDV recombinant plasmid (pP12A3C/IFN-CS/PLGA-NPs and pP12A3C/IFN-Am/MS-NPs) were used to induce mucosal and systemic immune responses in guinea pigs via intranasal delivery. Simultaneously, CpG oligodeoxy nucleotides (ODNs) as a vaccine adjuvant were encapsulated in chitosan-coated poly (lactic-co-glycolic acid) nanoparticles (CpG-CS/PLGA-NPs). The pP12A3C/IFN-CS/PLGA-NPs and CpG-CS/PLGA-NPs generated displayed good morphology, high stability, mean diameters of 500 and 400 nm and encapsulation efficiencies of 83.8% and 88.4%, respectively. Data from the in vitro release assay showed that plasmid and CpG were sustainably released from nanoparticles (up to 66.73% and 64%, respectively, of the total amount loaded). Guinea pigs immunized with pP12A3C/IFN-CS/PLGA-NPs + CpG-CS/PLGA-NPs showed markedly higher mucosal, cellular and humoral immune responses than those administered pP12A3C/IFN-CS/PLGA-NPs or naked plasmid vaccine alone. FMDV-specific secretory immunoglobulin A (sIgA) antibodies in nasal washes were initially detected at 3 days post-vaccination with CS/PLGA-NPs loaded with plasmid. Guinea pigs immunized with pP12A3C/IFN-CS/PLGA-NPs also displayed higher cellular and humoral immune responses than pP12A3C-CS/PLGA-NPs and naked plasmid vaccine alone. FMDV-specific immunoglobulin G (IgG) antibodies in serum were initially detected at 5 days post-vaccination (intramuscularly) with the naked plasmid. Finally, challenge experiments 42 days post-vaccine revealed 100% protection in guinea pigs immunized with pP12A3C/IFN-CS/PLGA-NPs + CpG-CS/PLGA-NPs and pP12A3C/IFN-CS/PLGA-NPs. However, plasmid DNA was burst released from pP12A3C/IFN-Am/MS-NPs. Our attempts to use pP12A3C/IFN-Am/MS-NPs to immunize guinea pigs failed to induce immune responses. In conclusion, CpG and IFN-α adjuvant based FMD vaccines elicit protection in guinea pigs. Moreover, CS-coated PLGA NPs present an efficient and safe mucosal immune delivery system for FMDV DNA vaccine. Data from the current study provide a foundation for understanding and further evaluating protective immune responses in pigs.

A bivalent B-cell epitope dendrimer peptide can confer long-lasting immunity in swine against foot-and-mouth disease.

Foot-and-mouth disease virus (FMDV) causes a widely extended contagious disease of livestock. We have previously reported that a synthetic dendrimeric peptide, termed B2 T(mal), consisting of two copies of a B-cell epitope [VP1(140-158)] linked through maleimide groups to a T-cell epitope [3A(21-35)] of FMDV, elicits potent B- and T-cell-specific responses and confers solid protection in pigs to type O FMDV challenge. Longer duration of the protective response and the possibility of inducing protection after a single dose are important requirements for an efficient FMD vaccine. Herein, we show that administration of two doses of B2 T(mal) elicited high levels of specific total IgGs and neutralizing antibodies that lasted 4-5months after the peptide boost. Additionally, concomitant levels of IFN-γ-producing specific T cells were observed. Immunization with two doses of B2 T(mal) conferred a long-lasting reduced susceptibility to FMDV infection, up to 136days (19/20weeks) post-boost. Remarkably, a similar duration of the protective response was achieved by a single dose of B2 T(mal). The effect on the B2 T(mal) vaccine of RNA transcripts derived from non-coding regions in the FMDV genome, known to enhance the immune response and protection induced by a conventional inactivated vaccine, was also analysed. The contribution of our results to the development of FMD dendrimeric vaccines is discussed.

Impact of foot-and-mouth-disease on goat behaviour after experimental infection with serotype SAT1 virus

Infectious diseases and parasitic infestations can cause a set of non-specific clinical signs, such as increased body temperature and resting, and a decrease in food intake. These physiological and behavioural changes have an adaptive function facilitating defences against the pathogen and to support immune functions. These so-called’ sickness behaviours’ can also be used as an early detection tool for disease. Foot-and-mouth disease (FMD) still causes great economic losses in endemic countries, especially to smallholder farmers. The aim of this study was to determine if behavioural changes in goats can be used as an early indicator of FMD virus (FMDV) infection. The efficacy of a Southern African Territories (SAT) FMD vaccine was studied on forty South African indigenous goats. Changes in daily activities (resting, feeding, walking), as well as social behaviours (social resting, social feeding, dominance behaviours) were recorded and then compared over time and between clinically affected and unaffected goats. Pedometers were used to estimate average daily steps and to compare between groups of study animals.Eleven goats developed clinical signs of FMD, as well as non-FMD related sicknesses during the course of the study. Overall walking and resting behaviours were not significantly affected by the presence of FMD related clinical signs (p > 0.05). However, during the time of FMDV infection, social resting increased significantly (p < 0.001). Although goats developed FMD lesions on lips and tongues, percentage of time feeding was not affected (p = 0.762), suggesting that the study goats did not perceive the oral lesions as an important disturbance. Similarly, the number of steps did not consistently decrease in the presence of FMD-associated foot lesions. When affected by non-FMD related sicknesses, animals did not have an overall reduction in the time spent feeding (p = 0.867). However, goats affected with non-FMD conditions reduced the amount of social feeding (p = 0.002), potentially avoiding energetically costly competition at the feeding points. Overall, goats affected with FMD did not show more sickness behaviour, suggesting that FMDV infection in goats might not lead to obvious and therefore, easily detectable behavioural changes. This might have implications for farmers and animal health personnel, as individual goats infected with FMDV might be undetected within a flock due to the absence of obvious sickness behaviours, and the virus can therefore be spread more easily between herds through animal movements.

Biosecurity in endemic foot and mouth disease settings: a case study of foot and mouth disease vaccination in South-East Asia.

Foot and mouth disease (FMD) is a highly contagious viral infection affecting cloven-hoofed animals including cattle, buffalo, sheep, goats and pigs. The disease is endemic in several parts of Asia, as well as most of Africa and the Middle East. In 1997, the World Organisation for Animal Health (OIE) established the South-East Asia Foot and Mouth Disease Campaign with the aim of increasing livestock sector productivity and economic output through the control and eradication of FMD in South-East Asia. Large-scale vaccination of livestock against FMD has in the past led to the successful eradication (or control) of the disease, for example in the Philippines. However, despite the benefit associated with large-scale vaccination, biosecurity risks can be created by vaccination teams moving between locations. It is therefore recommended that biosecurity measures are used by vaccination teams to prevent inadvertent disease spread. The majority of existing guidelines are focused on high-risk situations such as exotic animal disease outbreaks in developed countries, or agents posing a risk to human health. This paper describes the development of novel biosecurity guidelines for vaccination teams in South-East Asia. To achieve this, available literature was scanned followed by in-country workshops and field-testing of draft materials. Entry and exit procedures are laid out within the context of five core rules that follow the biosecurity principles of situational awareness, segregation, cleaning and disinfection. Guidelines and accompanying fact sheets were translated into local languages and included in a comprehensive vaccination training programme for all vaccination teams undertaking cattle FMD vaccination programmes in the New Zealand OIE FMD control project target countries (Myanmar and Laos). The material developed has wide practical relevance to veterinarians, traditional healers and village or community animal health workers, who all pose a heightened risk of spreading infectious agents.

Seroprevalence of serotype O of foot-and-mouth disease virus in vaccinated pigs and cattle in Ho Chi Minh City

The aim of this study was to assess the seroprevalence against serotype O FMD (foot and mouth disease) virus in vaccinated pigs and cattle in Ho Chi Minh City, as a basis to serve the prevention of FMD epidemics in these animals. A total of 535 pigs and 366cattle sera were tested by using the Elisa kit for the detection of serotype O FMD antibody (Pirbright, UK). Results of this study showed that most pig farms had the proportions of positive animals for antibodies against FMDV serotype O which met the requirements of Decision no. 07/2016/ Ministry of Agriculture and Rural Development, except Xuan Thoi Thuong, Thai My and Phu My Hung. All sows had high levels of antibodies against serotype O FMD virus. There were no significant differences in the ratios of positive pigs for antibodies against FMDV serotype O among types of pig and age groups. However, there were significant differences in the seroprevalence of vaccinated pigs across herd sizes and days post-vaccination. Meanwhile, the overall seroprevalence of vaccinated cattle against FMDV at individual-level was over 80.00%. No statistical differences were found in the seroprevalence of vaccinated cattle against type OFMDV among regions, types of cattle, herd sizes, age groups and days post-vaccination. In conclusion, pigs raised in farms of Xuan Thoi Thuong, Thai My and Phu My Hung communes should be revaccinated with FMD vaccine to prevent the risk of pigs being infected with FMD virus and reduce the amount of virus produced by an infected animal.

High-Resolution Composition Analysis of an Inactivated Polyvalent Foot-and-Mouth Disease Vaccine.

Appropriate vaccine selection is crucial in the control of foot-and-mouth disease (FMD). Vaccination can prevent clinical disease and reduces viral shedding, but there is a lack of cross-protection between the seven serotypes and their sublineages, making the selection of an adequately protective vaccine difficult. Since the exact composition of their vaccines is not consistently disclosed by all manufacturers, incompatibility of the strains used for vaccination with regionally circulating strains can cause vaccination campaigns to fail. Here, we present a deep sequencing approach for polyvalent inactivated FMD vaccines that can identify all component strains by their genome sequences. The genomes of all strains of a commercial pentavalent FMD vaccine were de novo assembled and the vaccine composition determined semi-quantitatively. The genome assembly required high stringency parameters to prevent misassemblies caused by conserved regions of the genome shared by related strains. In contrast, reference-guided assembly is only recommended in cases where the number of strains is previously known and appropriate reference sequences are available. The presented approach can be applied not only to any inactivated whole-virus FMD vaccine but also to vaccine quality testing in general and allows for better decision-making for vaccines with an unknown composition.

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

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

Engineering viable foot-and-mouth disease viruses with increased acid stability facilitate the development of improved vaccines

Foot-and-mouth disease virus (FMDV), the most acid-unstable virus among picornaviruses, tends to disassemble into pentamers at pH values slightly below neutrality. However, the structural integrity of intact virion is one of the most important factors that influence the induction of a protective antibody response. Thus, improving the acid stability of FMDV is required for the efficacy of vaccine preparations. According to the previous studies, a single substitution or double amino acid substitutions (VP1 N17D, VP2 H145Y, VP2 D86H, VP3 H142D, VP3 H142G, and VP1 N17D + VP2 H145Y) in the capsid were introduced into the full-length infectious clone of type O FMDV vaccine strain O/HN/CHN/93 to develop seed FMDV with improved acid stability. After the transfection into BSR/T7 cells of constructed plasmids, substitution VP1 N17D or VP2 D86H resulted in viable and genetically stable FMDVs, respectively. However, substitution VP2 H145Y or VP1 N17D + VP2 H145Y showed reverse mutation and additional mutations, and substitution VP3 H141G or VP3 H141D prevented viral viability. We found that substitution VP1 N17D or VP2 D86H could confer increased acid resistance, alkali stability, and thermostability on FMDV O/HN/CHN/93, whereas substitution VP1 N17D was observed to lead to a decreased replication ability in BHK-21 cells and mildly impaired virulence in suckling mice. In contrast, substitution VP2 D86H had no negative effect on viral infectivity. These results indicated that the mutant rD86H carrying substitution VP2 D86H firstly reported by us could be more adequate for the development of inactivated FMD vaccines with enhanced acid stability.

Determination of non-structural protein level for Turkey foot-and-mouth disease vaccine antigens during in-process.

PurposeThe success of foot-and-mouth disease (FMD) serological serosurveillance greatly depends on the FMD vaccine which does not include any non-structural proteins (NSPs) of the FMD virus. Since pure FMD vaccines from NSPs are used with the FMD eradication programs using DIVA (Differentiating Infected from Vaccinated Animals) tests. Apart from the in-vivo test defined in the World Organisation for Animal Health, two different test kits were developed in-process NSP detection purposes. The first test kit was developed in 2010 and the second one has been very recently developed in 2019.Materials and MethodsIn this study, the level of NSP has been examined by first-chemiluminescent filtration assisted (FAL)-enzyme-linked immunosorbent assay (ELISA) based in-vitro, in-process test kit for Turkey FMD vaccine antigen samples. A total of 94 samples were used. The critical maximum acceptable levels of NSP were determined after purification stage of samples.ResultsAs a maximum NSP level, 70 ng NSP for the polyethylene glycol concentrated samples and 30 ng NSP for the vaccine antigen mixture samples were accepted. A mini repeatability study was also performed. The correlation between the NSP, total protein, and 146S particul quantity of samples were analyzed.ConclusionAs a conclusion, the chemiluminescent FAL-ELISA based test kit can be used for the NSP purity level determination of in-process samples.

Determination of the Effect of Ecthyma Vaccine Virus on Immunity Against the Foot and Mouth Disease (Fmd) Vaccine in Sheep

Determination of the Effect of Ecthyma Vaccine Virus on Immunity Against the Foot and Mouth Disease (Fmd) Vaccine in Sheep

Recombinant vesicular stomatitis virus glycoprotein carrying a foot-and-mouth disease virus epitope as a vaccine candidate.

Foot-and-mouth disease (FMD) is one of the most highly contagious animal diseases. In an effort to overcome the drawbacks of the currently used inactivated foot-and-mouth disease virus vaccine, a novel recombinant protein carrying foot-and-mouth disease virus VP1 GH loop epitope linked to vesicular stomatitis virus glycoprotein was expressed in a baculovirus system. Its antigenicity was confirmed with ELISA using monoclonal antibody against foot-and-mouth disease virus. Twice immunizations one month apart in field pigs resulted in a significant antibody increase compared to the glutathione S-transferase carrier containing the same epitope and the commercial vaccine. To my knowledge, this is the first report that the recombinant protein vaccine was superior to the current vaccine. Although further studies are required to examine their immunogenicity in a large number of animals, this study sheds light on the development of a novel recombinant protein vaccine that could be easily produced in a general laboratory as an alternative to the current FMD vaccine, which requires a biosafety level 3 containment facility for vaccine production.

구제역 바이러스 O 혈청형 재조합 단백질 백신을 이용한 다종의 지역형 구제역 바이러스에 대한 교차방어력 연구

Foot and mouth disease (FMD) is a very contagious disease that occurs in cloven- hoofed livestock. This disease has an adverse effect on the livestock industry by causing blister in mouth and nose, anorexia, high fever and in particular sudden death to young animals. FMD virus (FMDV) has seven different serotypes: O, A, C, Asia1, SAT1, SAT2 and SAT3 but just two serotypes (O, A) have occurred in South Korea so far. In this study, we have developed recombinant protein antigen and verified protective efficacy as a FMD vaccine in contrast to widely used inactivated virus vaccine. Recombinant protein antigen is composed of repeated sequence of two epitopes (141-160, 200-213) of the VP1 of FMDV serotype O and pig immunoglobulin heavy chain as a carrier protein, and as a result, FMD vaccine has been produced by mixing paraffin oil. We have identified that antibody forms against FMDV in a vaccinated pig, measured protection rate against 3 topotypes of FMDV serotype O by excuting frequent challenge tests. It has shown above a certain level (≥80%) regardless of vaccination frequency. It suggests that recombinant protein, single antigen can respond to different topotypes in FMDV serotype O. We could assure that we have established the cornerstone for developing nonviral FMD vaccine that can protect against FMDV within the country and beyond neighboring countries.