Vaccination Of Goats Research Articles

Combined Proteomic and Metabolomic Analysis Reveals Comprehensive Regulation of Somatostatin DNA Vaccine in Goats.

Somatostatin (SS) plays crucial regulatory roles in animal growth and reproduction by affecting the synthesis and secretion of growth hormone (GH). However, the mechanism by which SS regulates growth and development in goats is still unclear. In order to investigate the regulatory networks of the hypothalamus and pituitary in goats affected by SS DNA vaccines, in this study, we used a previously established oral attenuated Salmonella typhimurium SS DNA vaccine, X9241 (ptCS/2SS-asd), to treat wethers. We analyzed the protein changes in hypothalamic and pituitary tissues using a TMT-based proteomics approach. Additionally, we examined the metabolic profiles of the serum of control and immunized wethers through untargeted metabolomics using liquid chromatography-mass spectrometry (LC-MS). Key signaling pathways were identified based on differentially expressed metabolites (DEMs) and differentially expressed proteins (DEPs). Furthermore, the effect of critical DEPs on signaling pathways was confirmed through Western blotting (WB) experiments, which elucidated the mechanism of active SS immunization in wethers. A proteomics analysis revealed that the expression of 58 proteins in the hypothalamus and 124 in the pituitary gland was significantly altered following SS vaccine treatment (fold change > 1.2 or < 0.83, p < 0.05). In the hypothalamus, many DEPs were associated with gene ontology (GO) terms related to neuronal signaling. In contrast, most DEPs were associated with metabolic pathways. In the pituitary gland, the DEPs were largely related to immune and nutrient metabolism functions, with significant enrichment in KEGG pathways, particularly those involving the metabolic pathway, sphingolipid signaling, and the cGMP-PKG signaling pathway. A metabolomic analysis further showed that active SS immunization in wethers led to significant alterations in seven serum metabolites. Notably, the sphingolipid signaling pathway, secondary bile acid synthesis, sphingolipid metabolism, and lysine synthesis were significantly disrupted. SS vaccines induced marked changes in hypothalamic-pituitary proteins in wethers, facilitating alterations in their growth processes. This study not only provides insights into the mechanism of the SS gene in regulating GH secretion in wethers but also establishes a basis for hormone immunoregulation technology to enhance livestock production performance.

Women's participation in and benefit from Rift Valley fever livestock vaccine value chain; current situation and barriers in Nyagatare District, Rwanda

Livestock vaccine value chains present opportunities for women's empowerment and income generation. To effectively position women to embrace these opportunities, understanding their current position and the factors that determine their involvement is crucial. This study mapped the actors, governance framework, and women's and men's positions along the value chain. It also analyzed gendered barriers to their participation and benefiting from services, processes, and products from the livestock Rift Valley fever vaccine value chain for livestock in Nyagatare District, Rwanda. Data was collected through 10 focus group discussions, 33 key informant interviews, and 1 stakeholder engagement meeting, while analysis was conducted thematically. Our results show that women's participation as importers, distributors, deliverers, or end-users was low to non-existent. Local gender norms curtailed women's participation and benefit at all nodes through restricted mobility, limited decision-making power, and restricted access to and control over resources. Additional barriers for stakeholders at the end-user node included a lack of knowledge about RVF vaccination in goats and how to demand or access the vaccine. This study recommends challenging persistent and limiting cultural norms through behavioral change communication by engaging men and boys as key actors for gender equality, engendering national and local planning and evaluation frameworks, and accelerating gender transformation in the private sector.

Immune response and safety of co-administered peste des petits ruminants, contagious caprine pleuropneumonia, sheep and goat pox, and Pasteurellosis vaccines in goats.

Infectious diseases such as peste des petits ruminants (PPRs), contagious caprine pleuropneumonia (CCPP), sheep and goat pox (SGPX), and pasteurellosis have considerable impacts on the optimal utilization of sheep and goat resources in Ethiopia. Immunization using multiple vaccines administered simultaneously has been suggested as a cost-effective and safe approach to controlling and preventing these diseases. The aim of this study was to assess the immunogenicity and safety of multiple vaccines administered simultaneously in goats. Sero-negative PPR, CCPP, SGPX, and Pasteurellosis goats were immunized with multiple vaccines. Goats vaccinated with a single vaccine against each disease served as a positive control. The immune response of the goats was assessed using serological tests, and any adverse effects were monitored. The results of the present study showed that goats vaccinated with multiple vaccines exhibited a remarkable immune response against PPR, CCPP, and pasteurellosis. In contrast, they did not produce a protective immune response against sheep or goat pox. No adverse effects were observed with any of the vaccines. This study suggested that combined vaccines can be effective at inducing a protective immune response in goats. However, further research is needed to fully understand the immune response to combined vaccines.

Multiple-Pathway Synergy Alters Steroidogenesis and Spermatogenesis in Response to an Immunocastration Vaccine in Goat.

Animal reproduction performance is crucial in husbandry. Immunocastrated animals serve as an ideal animal model for studying testicular function. During androgen suppression, the testis undergoes dramatic developmental and structural changes, including the inhibition of hormone secretion and spermatogenesis. To characterize this process, we investigated the effects of castration using a recombinant B2L and KISS1 DNA vaccine, and then identified functional genes in the testes of Yiling goats using RNA-seq and WGS. The experimental animals were divided into three groups: the PVAX-asd group (control), PBK-asd-immunized group, and surgically castrated group. The results demonstrated that the administration of the recombinant PBK-asd vaccine in goats elicited a significant antibody response, and reduced serum follicle-stimulating hormone (FSH) and luteinizing hormone (LH), resulting in smaller scrotal circumferences and decreased sexual desire compared to the control group. In addition, RNA transcriptome sequencing (RNA-seq) analysis of the testes revealed that the biological processes after immunocastration mainly focused on the regulation of cell matrix adhesion, histone acetylation, negative regulation of developmental processes, apoptosis, and activation of the complement system and the thrombin cascade reaction system. Then, we integrated the whole-genome sequencing and testis transcriptome, and identified several candidate genes (FGF9, FST, KIT, TH, TCP1, PLEKHA1, TMEM119, ESR1, TIPARP, LEP) that influence steroidogenesis secretion and spermatogenesis. Multiple pathways and polygenic co-expression participate in the response to castration vaccines, altering hormone secretion and spermatogenesis. Taken together, our atlas of the immunocastration goat testis provides multiple insights into the developmental changes and key factors accompanying androgen suppression, and thus may contribute to understanding the genetic mechanism of testis function. Joint analysis of whole genome sequencing and RNA-seq enables reliable screening of candidate genes, benefiting future genome-assisted breeding of goats.

Investigation of Potency and Safety of Live-Attenuated Peste des Petits Ruminant Virus Vaccine in Goats by Detection of Cellular and Humoral Immune Response.

The peste des petits ruminant (PPR) virus is a transboundary virus found in small domestic ruminants that causes high morbidity and mortality in naive herds. PPR can be effectively controlled and eradicated by vaccinating small domestic ruminants with a live-attenuated peste des petits ruminant virus (PPRV) vaccine, which provides long-lasting immunity. We studied the potency and safety of a live-attenuated vaccine in goats by detecting their cellular and humoral immune responses. Six goats were subcutaneously vaccinated with a live-attenuated PPRV vaccine according to the manufacturer's instructions, and two goats were kept in contact. Following vaccination, the goats were monitored daily, and we recorded their body temperature and clinical score. Heparinized blood and serum were collected for a serological analysis, and swab samples and EDTA blood were collected to detect the PPRV genome. The safety of the used PPRV vaccine was confirmed by the absence of PPR-related clinical signs, a negative pen-side test, a low virus genome load as detected with RT-qPCR on the vaccinated goats, and the lack horizontal transmission between the in-contact goats. The strong humoral and cellular immune responses detected in the vaccinated goats showed that the live-attenuated PPRV vaccine has a strong potency in goats. Therefore, live-attenuated vaccines against PPR can be used to control and eradicate PRR.

Stimulating immunoglobulin response by intramuscular delivery of exopolysaccharides-adjuvanted mannheimiosis vaccine in goats.

Pneumonic mannheimiosis (PM) is a common respiratory bacterial disease among small ruminants. Despite numerous management methods, vaccination remains a suitable strategy to combat or reduce PM in goats and sheep. Thus, a study was conducted in Malaysia to evaluate the immunogenicity of exopolysaccharide-adjuvanted Mannheimia haemolytica A2 vaccine (EPS-MHA2) under laboratory and field conditions for its potential use as an efficient vaccine against PM. This study induced immunoglobulin (Ig) responses following intramuscular (IM) delivery of the EPS-MHA2 vaccine on 12 goats for about 7 months. Goats were divided into three groups, with three goats per group, and they were vaccinated intramuscularly as follows: Group 1 was vaccinated with an adjuvanted vaccine prepared from formalin-killed M. haemolytica serotypes A2 and EPS excipient; Group 2 was vaccinated with formalin-killed M. haemolytica seed only, whereas Group 3 was injected with phosphate-buffered saline (PBS) as the negative control. Measures of specific immunity included serum IgM, IgG, and IgA as well as bronchoalveolar lavage fluid secretory IgA and the size and number of the bronchus-associated lymphoid tissue (BALT). From the 1st day of vaccination, Groups 1 and 2 showed a significant (p < 0.05) increase in serum IgM, IgG, and IgA levels. However, the antibodies started to decline 5-week post-vaccination, indicating that the booster dose was necessary. On the second exposure to the same vaccine (booster), the level of antibodies showed a significant increase (p < 0.05), particularly IgG. All groups were challenged intratracheally by virulent MHA2 2 weeks after the decline of second antibodies on the administration of booster. All goats were euthanatized and necropsied 4-week post-challenge. The number and size of the BALT in Group 1 goats significantly increased compared with those in Group 2 and the unvaccinated control. Bacteriological parameters were evaluated, in which MHA2 was reisolated successfully from lung samples in Group 3. The IgA level produced by the group vaccinated with EPS-MHA2 was significantly (p < 0.001) higher than that the MHA2 vaccine and PBS groups. All data obtained were analyzed statistically using a one-way analysis of variance. The results indicate that IM injection of EPS-MHA2 vaccine significantly enhanced the immune response against MHA2. Therefore, the addition of EPS to MHA2 (EPS-MHA2 vaccine) can effectively protect goats from lethal mannheimiosis infection. Factors such as the ideal concentration of EPS should be further studied to verify its application potential as a vaccine adjuvant, and the extraction of EPS from different microalgae species should be further investigated. This study showed a novel and exciting set of data and a vaccination system, in which the suppressive effects of mannheimiosis may be further investigated.

A proof-of-concept study to investigate the efficacy of heat-inactivated autovaccines in Mycobacterium caprae experimentally challenged goats

This study aimed to assess the efficacy of a heat-inactivated Mycobacterium caprae (HIMC) vaccine in goats experimentally challenged with the same strain of M. caprae. Twenty-one goats were divided into three groups of seven: vaccinated with heat-inactivated Mycobacterium bovis (HIMB), with HIMC and unvaccinated. At 7 weeks post-vaccination all animals were endobronchially challenged with M. caprae. Blood samples were collected for immunological assays and clinical signs were recorded throughout the experiment. All goats were euthanized at 9 weeks post-challenge. Gross pathological examination, analysis of lung pathology using computed tomography, and bacterial load quantification in pulmonary lymph nodes (LN) by qPCR were carried out. Only HIMC vaccinated goats showed a significant reduction of lung lesions volume and mycobacterial DNA load in LN compared to unvaccinated controls. Both vaccinated groups showed also a significant reduction of the other pathological parameters, an improved clinical outcome and a higher proportion of IFN-γ-producing central memory T cells after vaccination. The results indicated that homologous vaccination of goats with HIMC induced enhanced protection against M. caprae challenge by reducing lung pathology and bacterial load compared to the heterologous vaccine (HIMB). Further large-scale trials are necessary to assess the efficacy of autovaccines under field conditions.

Fecal parasitic load due to parenteral administration of Levamisole and antioxidants during PPR vaccination in goats

In the present study, fecal parasitic load of Rohilkhandi goat kids were evaluated due to injectable antioxidants and Levamisole during PPR vaccination. 18 goats were randomly distributed in three groups based on their body weight and age i.e., CON: vaccinated with no treatment; T1: vaccinated with Levamisole (commercial available) administration; T2: vaccinated with antioxidants administration (vitamin E and selenium). The study period lasted for 14 days. The data recorded revealed a decrease from day 0 to day 14 in shedding of oocysts per gram and OPG of feces of all animals. However, the variations in and PEG OPG between groups at different time periods were statistically non-significant (p>0.05). It can be stated that both Levamisole and antioxidants supplementation can help in reducing PEG and OPG in feces of animals during PPR vaccination.

Determinants of smallholder farmers' membership in co-operative societies: evidence from rural Kenya

PurposeDespite the potential for co-operatives to improve smallholder farmers' livelihoods, membership in the co-operatives is low. This study examines factors that influence smallholder farmers' decisions to join agricultural co-operatives.Design/methodology/approachThis study involved a survey of 1,274 smallholder chicken farmers. The data were analysed through a two-sample t-test of association, Pearson's Chi-square test and binary probit regression model.FindingsThe results suggest that farming as the main source of income, owning a chicken house, education attainment, attending training or accessing information, vaccination of goats and keeping a larger herd of goats are the key factors which significantly influence co-operative membership. However, gender, age, household size, distance to the nearest agrovet, vaccinating chicken and the number of chickens kept do not influence co-operative membership.Research limitations/implicationsThe survey did not capture data on some variables which have been shown to influence co-operative membership. Nevertheless, the results show key explanatory variables which influence membership in co-operatives.Practical implicationsThese findings have implications for development agencies that seek to use co-operatives for agricultural development and improvement of smallholder farmers' livelihoods. The agencies can use the results to initiate interventions relevant for different types of smallholder farmers through co-operatives.Originality/valueThis study highlights the influence of smallholder farmers' financial investments in farming and the extent of commercialisation on co-operative membership. Due to low membership in co-operatives, recognising the heterogeneity of smallholder farmers is the key in agricultural development interventions through co-operative membership.Peer reviewThe peer review history for this article is available at: https://publons.com/publon/10.1108/IJSE-03-2022-0165.

Coinfection kinetics of goatpox virus and peste-des-petits-ruminants virus in Vero cells.

Goatpox, sheeppox, and peste-des-petits-ruminants (PPR) are economically important virus diseases affecting goats and sheep, which often cause coinfection/comorbidities in the field. Coinfection with these viruses leads to enhanced infection in natural scenarios in terms of morbidities and mortalities. Currently, individual live attenuated vaccines are being used to mitigate these diseases and research on combination vaccines for these diseases is encouraging. For the preparation of combination vaccines, vaccine strains of the peste-des-petits-ruminants virus (PPRV), goatpox virus (GTPV), and sheeppox virus (SPPV) are grown separately and GTPV + PPRV are mixed for vaccination of goats, and PPRV + SPPV for sheep. Growing capripox and PPRV strains in the same cells simultaneously without the titer loss will save the time and cost of production. In the current study, we have evaluated the coinfection kinetics of capripox virus and a PPRV using a candidate GTPV vaccine strain (originally caused infection in both goats and sheep in the field) and PPRV/Sungri/96 (vaccine strain) in Vero cells. At high multiplicity of infection (MOI), PPRV was excluded from coinfection by GTPV, whereas at a low multiplicity coexistence/accommodation was observed between PPRV and GTPV without loss of the titer. The results shed light on the possibility of the production of two vaccine strains in the same cells using the coinfection model economically.

Long-term protective immunity to goatpox in goats after a single immunization with a live attenuated goatpox vaccine

In this study, the duration of immunity following a single-dose vaccination using an attenuated live goatpox vaccine (GTPV/Uttarkashi/1978 strain) was evaluated in goatpox-seronegative goats for 52 months. Long-term immunity was evaluated by clinical protection upon virulent virus challenge and serum neutralization assay applied to serum samples. The rise in the level of GTPV-specific antibodies was found to reach a maximum at 21days post-vaccination, and these antibodies were maintained for 1 to 2years after immunization, with a steady decline. Upon virulent virus challenge at 12, 24, 42, and 52months post-vaccination, protection in all the vaccinated animals was evident (100%), whereas, the control animals developed severe clinical disease. This is the first time that the long-term immunity of a live goatpox vaccine has been investigated up to 52months after vaccination in goats by virulent virus challenge and demonstration of serum neutralization titres. This vaccine has immense potential for controlling and eradicating goatpox from an enzootic region.

Comparative Effects of Deworming, Mineral and Vitamin Supplementation on Humoral Response against Peste de Petits Ruminants Vaccine in Goats

Comparative Effects of Deworming, Mineral and Vitamin Supplementation on Humoral Response against Peste de Petits Ruminants Vaccine in Goats

Cattle and goats’ humoral response to vaccination with Clostridium perfringens type D purified epsilon toxoids

Herd vaccination is an important preventive measure against enterotoxemia in ruminants. Vaccination in goats should be performed every four months, and recent studies have shown that immunity in cattle lasts for less than one year. One of the mechanisms for increasing the duration of the immune response is to use purified toxoids as immunogens. The aim of the present study was to evaluate the humoral response in cattle and goats after vaccination with purified and semi-purified Clostridium perfringens type D epsilon toxoid. The following three different vaccines were used: vaccine 1 (V1), a semi-purified toxoid adsorbed to aluminum hydroxide; vaccine 2 (V2), a purified toxoid adsorbed to aluminum hydroxide; and vaccine (V3), a purified toxoid adsorbed on chitosan microparticles. Groups of cattle (n = 6–7) and goats (n = 6–7) were vaccinated on days 0 and 30, and serum samples for antitoxin titration were collected every 30 days for one-year post-vaccination. Goats were revaccinated on day 360, and their serum was evaluated on days 367 and 374. The antibody peaks ranged between 6.90 and 11.47 IU/mL in cattle and from 1.11 to 4.40 IU/mL in goats. In cattle administered with the V1 and V2 vaccines, we observed that the antibody titers were maintained above 0.2 IU/mL until the end of the experiment. In goats, V2 elicited long-lasting antibodies, and all animals maintained the protective titers for 210 days after the first dose. In conclusion, the purified toxoid vaccine with aluminum hydroxide adjuvant was able to induce strong and long-lasting humoral responses in both species and could be an alternative for improving the immunization schedule against enterotoxemia in goats and cattle.

Biomarkers, immune responses and cellular changes in vaccinated and non-vaccinated goats during experimental infection of M. haemolytica A2 under tropical conditions

BackgroundWe investigated the biomarkers, immune responses and cellular changes in vaccinated and non-vaccinated goats experimentally challenged with M. haemolytica serotype A2 under rainy and hot tropical conditions. A total of twenty-four clinically healthy, non-pregnant, female goats randomly allocated to 2 groups of 12 goats each were used for the study. The 12 goats in each season were subdivided into three groups (n = 4), which served as the control (G-NEG), non-vaccinated (G-POS), and vaccinated (G-VACC). In week-1, the G-VACC received 2 mL of alum-precipitated pasteurellosis vaccine while G-POS and G-NEG received 2 ml of sterile PBS. In week 2, the G-POS and G-VACC received 1 mL intranasal spray containing 105 CFU of M. haemolytica serotype A2. Inoculation was followed by daily monitoring and weekly bleeding for eight weeks to collect data and serum for biomarkers and immune responses using commercial ELISA test kits. The goats were humanely euthanised at the end of the experiments to collect lungs and the submandibular lymph nodes tissue samples for gross and histopathological examinations. ResultsRegardless of the season, we have observed a significant (p < 0.05) increase in serum concentrations of acute-phase proteins (haptoglobin, serum amyloid A), proinflammatory cytokines (interleukine-1β, interleukin-6), antibodies (immunoglobulin M, immunoglobulin G), and stress markers (cortisol and heat shock protein 70) in the G-POS goats compared to G-VACC and G-NEG. With regards to seasons, there was a significantly (p < 0.05) higher serum concentration with 1.5, 2 and 1-folds increase in the serum interleukin (IL)-1β, cortisol, and heat shock protein (HSP)-70 in the G-POS during rainy compared to the hot season. Histopathology of the lungs in G-POS goats revealed inflammatory cell infiltration, degeneration, haemorrhage/congestion, and pulmonary oedema in the alveoli spaces; thickening of the interstitium, and desquamation of bronchiolar epithelium. Cellular changes in the lymph node were characterized by a marked hypercellularity in G-POS goats. ConclusionHost responses to pneumonic mannheimiosis based on increased serum levels of biomarkers (cortisol, HSP70, IL-1β and IL-6) and severe cellular changes seen in the lungs and lymph nodes of G-POS goats compared to vaccinated goats and control group are influenced by the high environmental humidity recorded in the rainy season. Increased relative humidity in the rainy season is a significant stress factor for the higher susceptibility and severity of pneumonic mannheimiosis of goats in the tropics. Vaccination of goats using the alum precipitated Pasteurella multocida vaccine before the onset of the rainy season is recommended to minimise mortality due to potential outbreaks of pneumonia during the rainy season.

Systems Biology behind Immunoprotection of Both Sheep and Goats after Sungri/96 PPRV Vaccination.

ABSTRACTImmune response is a highly coordinated cascade involving all the subsets of peripheral blood mononuclear cells (PBMCs). In this study, RNA sequencing (RNA-Seq) analysis of PBMC subsets was done to delineate the systems biology behind immune protection of the vaccine in sheep and goats. The PBMC subsets studied were CD4+, CD8+, CD14+, CD21+, and CD335+ cells from day 0 and day 5 of sheep and goats vaccinated with Sungri/96 peste des petits ruminants virus. Assessment of the immune response processes enriched by the differentially expressed genes (DEGs) in all the subsets suggested a strong dysregulation toward the development of early inflammatory microenvironment, which is very much required for differentiation of monocytes to macrophages, and activation as well as the migration of dendritic cells into the draining lymph nodes. The protein-protein interaction networks among the antiviral molecules (IFIT3, ISG15, MX1, MX2, RSAD2, ISG20, IFIT5, and IFIT1) and common DEGs across PBMC subsets in both species identified ISG15 to be a ubiquitous hub that helps in orchestrating antiviral host response against peste des petits ruminants virus (PPRV). IRF7 was found to be the key master regulator activated in most of the subsets in sheep and goats. Most of the pathways were found to be inactivated in B lymphocytes of both the species, indicating that 5 days postvaccination (dpv) is too early a time point for the B lymphocytes to react. The cell-mediated immune response and humoral immune response pathways were found more enriched in goats than in sheep. Although animals from both species survived the challenge, a contrast in pathway activation was observed in CD335+ cells.IMPORTANCE Peste des petits ruminants (PPR) by PPR virus (PPRV) is an World Organisation for Animal Health (OIE)-listed acute, contagious transboundary viral disease of small ruminants. The attenuated Sungri/96 PPRV vaccine used all over India against this PPR provides long-lasting robust innate and adaptive immune response. The early antiviral response was found mediated through type I interferon-independent interferon-stimulated gene (ISG) expression. However, systems biology behind this immune response is unknown. In this study, in vivo transcriptome profiling of PBMC subsets (CD4+, CD8+, CD14+, CD21+, and CD335+) in vaccinated goats and sheep (at 5 days postvaccination) was done to understand this systems biology. Though there are a few differences in the systems biology across cells (specially the NK cells) between sheep and goats, the coordinated response that is inclusive of all the cell subsets was found to be toward the induction of a strong innate immune response, which is needed for an appropriate adaptive immune response.

Detection of Peste des petits ruminants virus antibodies in sera of buffaloes

In Indian state of Tamil Nadu, six districts were chosen and 120 serum samples collected from selected herds of buffaloes. These sera were screened for peste des petits ruminants virus (PPRV) antibodies using cELISA and micro SNT. Though the sample size is small to assess the extent of seropositivity, both the tests showed 15% (9/60) positivity for PPRV antibodies in selected herds of buffaloes in the areas without previous history of PPRV disease incidence and PPRV vaccination in goats and sheep, whereas, 28.3% (17/60) positivity was found in selected herds of buffaloes with previous history of PPRV disease incidence and PPRV vaccination in goats and sheep under field/farmers’ holdings. The buffaloes did not exhibit any clinical sign though there was seropositivity.

Long-term efficacy of BCG vaccination in goat herds with a high prevalence of tuberculosis

Vaccination of goats against tuberculosis (TB) has been promoted as an ancillary tool for controlling the disease in infected livestock herds. A three-year trial to assess the efficacy of BCG vaccine was carried out in five goat herds. At the beginning of the trial (month 0), all animals were tested for TB using thee different diagnostic tests. Animals negative to all tests were vaccinated with BCG and all replacement goat kids were also systematically vaccinated throughout the trial. All animals were tested by Interferon-gamma release assay (IGRA) using vaccine compatible reagents at months 6, 12, 24, and 36. The risk factors for TB infection were also evaluated. At the end of the study, four out of five farms showed variable reductions of the initial prevalence (93.5%, 28.5%, 23.2%, and 14.3% respectively), and an overall incidence reduction of 50% was observed in BCG vaccinated goats, although adult vaccinated goats showed higher incidences than vaccinated goat kids. The unvaccinated positive animals remaining in herds and adult BCG vaccinated goats significantly enhanced the risk of infection in vaccinated animals. A systematic vaccination of goats with BCG, together with the removal of positive unvaccinated animals, may contribute to reducing the TB prevalence in goat herds.

Assessment of the Immunogenicity of a Novel Live Recombinant Rift Valley Fever arMP-12andDelta;NSm21/384 Vaccine Candidate Following Intranasal Vaccination of Goats, Sheepand Calves in Tanzania

Background: Rift Valley fever virus (RVFV) is an arbovirus that causes morbidity and mortality in livestock and humans throughout Africa and in the Arabian Peninsula. Vaccines are effective for the prevention of Rift Valley fever (RVF) disease, but new and improved vaccines are needed to improve the safety of available vaccines. Also, non-invasive needle free vaccine delivery routes should be evaluated as an alternative for invasive routes of vaccination. Objective: The aim of this proof of concept study was to evaluate the safety and immunogenicity of a novel live attenuated recombinant RVFV arMP-12ΔNSm21/384 vaccine candidate following intranasal vaccination of goats, calves, and sheep in Tanzania. Methods: Healthy, 6-9 months old breeds of African sheep (Ovis aeris), goats (Capra aegagrus) and zebu calves (Bos taurus indicus) were used in this study. The animals were purchased from local livestock keepers in the Mvomero district of Morogoro region, Tanzania. Animals were seronegative to both RVFV and antibody at the time of use in the vaccine trials. Animals in the test group included 10 goats, 7 sheep and 10 calves that were vaccinated in the left nares with 50 μl each and 2 sheep were vaccinated with 100 μl each (50 μl each in the left and right nares) of a dose that contained 4 × 105 PFU/50 ul of arMP-12ΔNSm21/384 vaccine, while the control group, including 2 goats, 3 sheep and 2 calves that were injected in the left nares with 50 μl of phosphate buffered saline to serve as placebo controls. Rectal temperature was measured and blood samples were collected on day 14 and 0 before vaccination, and on days 3, 5, 7, 14, 21, 28 and 35 post vaccinations (PV). Serum samples collected on days 14 and 0 before vaccination were tested for RVFV neutralizing antibody by a plaque reduction neutralization test, and on days 3 and 5 PV, serum samples were tested for virus as possible evidence of a viremia in cell culture and weekly collected samples thereafter were tested for RVFV neutralizing antibody. Results: All animals were negative for RVFV neutralizing antibody at 14 and 0 days before vaccination and none of the animals had detectable viremia on days 3 and 5 PV, and none had clinical manifestations throughout the study. Among the 7 sheep, 10 goats, and 10 calves that received 50 μl each of the vaccine dose, 70% had the first detectable antibody on either day 5, 7 or 14 PV with titers ranging from 1:10 to 1:40. The 2 sheep that received the 100 μl each of the virus dose had the first detectable antibody on day 5 PV with a titer of 1:160. Subsequently, animals vaccinated with the 50 μl dose had antibody titers ranged from 1:10 to 640 on days 21, 28 and 35 PV, while those vaccinated with 100 μl maintained an antibody titer of 1:160 throughout the study. Moreover, there was no difference in the antibody titers between animal species p=0.34, although mean antibody titers of goats were highest. Conclusion: As a proof of concept studies, the findings demonstrated that intranasal vaccination is a promising route for vaccinating domestic ruminants with the RVFV arMP-12ΔNSm21/384 vaccine candidate. However, these preliminary results suggested that a larger dose of 4 × 105 PFU/100 ul of arMP-12ΔNSm21/384 vaccine needed to be administered to each animal to consistently elicit a robust immune response. Also, further studies are warranted using a larger number of domestic ruminants to confirm the immune response elicited by the larger dose of the vaccine administered via the intranasal route.

Intranasal Peste des petits ruminants virus vaccination of goats using Irvingia gabonensis gum as delivery system: hematological and humoral immune responses

ABSTRACT Peste des petits ruminants (PPR) in Africa continues to defy conventional vaccinational approaches aimed at its control. There is need for route modification and immunopotentiation of the current vaccination methods, using easily affordable materials. This study evaluates the immunomodulatory potential of Irvingia gabonensis (IG) seed gum extract for intranasal PPR vaccination in goats using attenuated Nigeria 75/1 PPR vaccine. Twenty West African dwarf goats were divided into four groups (n=5). Group 1 was vaccinated intranasally using IG gum as vehicle; Group 2 was vaccinated intranasally without the gum; Group 3 via subcutaneous injection while Group 4 was not vaccinated. Hematology and Serum IgG levels were assessed weekly for 28 days post vaccination (dpv). H-PPR bELISA detected antibodies against PPR by 7th dpv, peaking by 21st dpv with mean percentage inhibitions of 78.2%; 69.6%; 87.0% and 0% in Groups 1, 2, 3 and 4, respectively. Also, significantly lower neutrophil to lymphocyte ratio (P<0.05) were observed by 14th dpv to 28th dpv in the vaccinated groups. The findings of this study show that the use of I. gabonensis seed gum extract for mucoadhesive intranasal PPR vaccine delivery has an immunomodulatory effect on the systemic immune response following PPR intranasal vaccine administration.

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.