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Chaiyabutr N, Wattanaphansak S, Tantilerdcharoen R, Akesowan S, Ouisuwan S, Naraporn D. Comparative immune responses after vaccination with the formulated inactivated African horse sickness vaccine serotype 1 between naïve horses and pretreated horses with the live-attenuated African horse sickness vaccine. Vet World 2022; 15:2365-2375. [DOI: 10.14202/vetworld.2022.2365-2375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Accepted: 08/23/2022] [Indexed: 11/16/2022] Open
Abstract
Background and Aim: African horse sickness (AHS) is a non-contagious, high mortality, and insect-borne disease caused by a double-stranded RNA virus from the genus Orbivirus. The study aimed to develop inactivated vaccines serotype 1 inactivated AHS vaccine (IAV) and to compare the effect of IAV on antibody responses in young naïve horses and adult horses pre-immunized with live-attenuated AHS virus (AHSV) serotypes 1, 3, and 4 live-attenuated vaccine (LAV).
Materials and Methods: A total of 27 horses were vaccinated in two trials. Twelve AHS naïve young horses and 15 adult horses were divided into three groups of 4 and 5 horses each, respectively. Horses in control Group 1 were treated with phosphate-buffered saline. Horses in Group 2 were subcutaneously vaccinated with 2 mL of formulated IAV with 10% Gel 01™ (Seppic, France) on day 0 and horses in Group 3 were subcutaneously vaccinated with 2 mL of IAV on day 0 and a booster on day 28. The IAV vaccine was prepared by isolating the AHSV serotype 1 growing on Vero cells, 10× virus titer was concentrated by ultrafiltration and chemically killed by formalin, using 10% Gel 01™ as an adjuvant. Ethylenediaminetetraacetic acid blood samples were taken for hematology, blood biochemistry, and antibody titers using an immunoperoxidase monolayer assay on 158th day post-vaccination.
Results: Vaccination with IAV serotype 1 in adult horses pretreated with LAV increased antibody titers more than in young naïve vaccinated horses. The total leukocyte count and %neutrophils significantly increased, while %lymphocytes and %eosinophils significantly decreased on day 1 after vaccination; no local reactions were observed at the site of injection in any group. All biochemical and electrolyte analyte values were within the normal range after vaccination.
Conclusion: The formulation of IAV serotype 1 using Gel 01™ as an adjuvant is safe and induces high antibody titers. This IAV formulation induced a high antibody response in horses without causing local reactions and mild systemic effects. However, AHS naïve horses still required ≥2 vaccinations and an annual booster vaccination to achieve high antibody titers.
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Affiliation(s)
- Narongsak Chaiyabutr
- Department of Research and Development, Queen Saovabha Memorial Institute, Thai Red Cross Society, Bangkok, Thailand; Department of Physiology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand
| | - Suphot Wattanaphansak
- Department of Veterinary Medicine, Faculty of Veterinary Science Chulalongkorn University, Bangkok, Thailand
| | - Rachod Tantilerdcharoen
- Veterinary Diagnostic Laboratory, Faculty of Veterinary Science Chulalongkorn University, Bangkok, Thailand
| | - Surasak Akesowan
- Horse Farm and Laboratory Animal Breeding Centre, Queen Saovabha Memorial Institute, Thai Red Cross Society, Petchaburi, Thailand
| | - Suraseha Ouisuwan
- Horse Farm and Laboratory Animal Breeding Centre, Queen Saovabha Memorial Institute, Thai Red Cross Society, Petchaburi, Thailand
| | - Darm Naraporn
- Horse Farm and Laboratory Animal Breeding Centre, Queen Saovabha Memorial Institute, Thai Red Cross Society, Petchaburi, Thailand
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Fearon SH, Dennis SJ, Hitzeroth II, Rybicki EP, Meyers AE. Plant expression systems as an economical alternative for the production of iELISA coating antigen AHSV VP7. N Biotechnol 2022; 68:48-56. [DOI: 10.1016/j.nbt.2022.01.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 12/28/2021] [Accepted: 01/28/2022] [Indexed: 10/19/2022]
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Fearon SH, Dennis SJ, Hitzeroth II, Rybicki EP, Meyers AE. Humoral and cell-mediated immune responses to plant-produced African horse sickness virus VP7 quasi-crystals. Virus Res 2021; 294:198284. [PMID: 33421520 DOI: 10.1016/j.virusres.2020.198284] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 12/22/2020] [Accepted: 12/26/2020] [Indexed: 11/26/2022]
Abstract
African horse sickness (AHS) is a devastating viral disease affecting equines and has resulted in many disastrous epizootics. To date, no successful therapeutic treatment exists for AHS, and commercially used live-attenuated vaccines have various undesirable side effects. Previous studies have shown that mice inoculated with insoluble African horse sickness virus (AHSV) VP7 crystals are protected from live challenge with a lethal dose of AHSV. This study investigates the humoral and cell-mediated immune responses in guinea-pigs to a safer monovalent vaccine alternative based on AHSV-5 VP7 quasi-crystals produced in plants. Guinea-pigs received prime- and boost-inoculations of between 10 and 50 μg of purified plant-produced AHSV VP7. Western immunoblot analysis of the humoral response showed stimulation of high titres of anti-VP7 antibodies 28 days after the boost-inoculation in sera from three of the five experimental animals. In addition, RNA-seq transcriptome profiling of guinea-pig spleen-derived RNA highlighted thirty significantly (q ≤ 0.05) differentially expressed genes involved in innate and adaptive immunity. Differential expression of genes involved in Th1, Th2 and Th17 cell differentiation suggest a cell-mediated immune response to AHSV-5 VP7. Upregulation of several important cytokines and cytokine receptors were noted, including TNFSF14, CX3CR1, IFNLR1 and IL17RA. Upregulation of IL17RA suggests a Th17 response which has been reported as a key component in AHSV immunity. While further investigation is needed to validate these findings, these results suggest that AHSV-5 VP7 quasi-crystals produced in N. benthamiana are immunogenic and induce both humoral and cell-mediated responses.
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Affiliation(s)
- Shelley H Fearon
- Biopharming Research Unit, Department of Molecular and Cell Biology, University of Cape Town, Rondebosch, Cape Town 7700, South Africa
| | - Susan J Dennis
- Biopharming Research Unit, Department of Molecular and Cell Biology, University of Cape Town, Rondebosch, Cape Town 7700, South Africa
| | - Inga I Hitzeroth
- Biopharming Research Unit, Department of Molecular and Cell Biology, University of Cape Town, Rondebosch, Cape Town 7700, South Africa
| | - Edward P Rybicki
- Biopharming Research Unit, Department of Molecular and Cell Biology, University of Cape Town, Rondebosch, Cape Town 7700, South Africa; Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Rondebosch, Cape Town 7700, South Africa
| | - Ann E Meyers
- Biopharming Research Unit, Department of Molecular and Cell Biology, University of Cape Town, Rondebosch, Cape Town 7700, South Africa.
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van Rijn PA, Maris-Veldhuis MA, Grobler M, Wright IM, Erasmus BJ, Maartens LH, Potgieter CA. Safety and efficacy of inactivated African horse sickness (AHS) vaccine formulated with different adjuvants. Vaccine 2020; 38:7108-7117. [PMID: 32921506 DOI: 10.1016/j.vaccine.2020.08.072] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 08/24/2020] [Accepted: 08/29/2020] [Indexed: 12/11/2022]
Abstract
African horse sickness virus (AHSV) is a virus species in the genus Orbivirus of the family Reoviridae causing African Horse Sickness (AHS) in equids with a mortality of about 95% in naïve horses. AHS causes serious losses in developing countries where horses play a central role in draft power and transportation. There are nine AHSV serotypes inducing no or low cross-neutralizing antibodies. AHSV is spread by biting Culicoides midges. AHS is endemic in sub-Saharan Africa, and a serious threat outside Africa, since Culicoides species in moderate climate conditions are spreading the closely related bluetongue virus. AHS outbreaks will be devastating for the equestrian industry in developed countries. Live-attenuated vaccines (LAVs) are licensed, marketed and in use in Africa. Their application is controversial with regard to safety issues. LAVs are not allowed in AHS-free countries. We here studied inactivated AHSV with different adjuvants in guinea pigs and horses. Subcutaneous and intramuscular vaccination were studied in horses. Local reactions were observed after prime and boost vaccination. In general, neutralizing antibodies (nAbs) titres were very low after prime vaccination, whereas boost vaccination resulted in high nAb titres for some adjuvants. Vaccinated horses were selected based on local reactions and nAb titres to study efficacy. Unfortunately, not all vaccinated horses survived virulent AHSV infection. Further, most survivors temporarily developed clinical signs and viremia. Further, the current prototype inactivated AHS vaccine is not suitable as emergency vaccine, because onset of protection is slow and requires boost vaccinations. On the other hand, inactivated AHS vaccine is completely safe with respect to virus spread, and incorporation of the DIVA principle based on NS3/NS3a serology and exploring a vaccine production platform for other serotypes is feasible. A superior adjuvant increasing the protective response without causing local reactions will be required to develop payable and acceptable inactivated AHS vaccines.
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Affiliation(s)
- Piet A van Rijn
- Department of Virology, Wageningen Bioveterinary Research (WBVR), Lelystad, The Netherlands; Department of Biochemistry, Centre for Human Metabolomics, North-West University, Potchefstroom, South Africa.
| | - Mieke A Maris-Veldhuis
- Department of Virology, Wageningen Bioveterinary Research (WBVR), Lelystad, The Netherlands
| | - Miemie Grobler
- Department of Production Animal Studies, University of Pretoria, South Africa
| | - Isabel M Wright
- Deltamune (Pty) Ltd, Moraine house - The Braes, 193 Bryanston Drive, Bryanston, Gauteng 2191, South Africa
| | - Baltus J Erasmus
- Deltamune (Pty) Ltd, Moraine house - The Braes, 193 Bryanston Drive, Bryanston, Gauteng 2191, South Africa
| | - Louis H Maartens
- Deltamune (Pty) Ltd, Moraine house - The Braes, 193 Bryanston Drive, Bryanston, Gauteng 2191, South Africa
| | - Christiaan A Potgieter
- Deltamune (Pty) Ltd, Moraine house - The Braes, 193 Bryanston Drive, Bryanston, Gauteng 2191, South Africa; Department of Biochemistry, Centre for Human Metabolomics, North-West University, Potchefstroom, South Africa
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Rutkowska DA, Mokoena NB, Tsekoa TL, Dibakwane VS, O’Kennedy MM. Plant-produced chimeric virus-like particles - a new generation vaccine against African horse sickness. BMC Vet Res 2019; 15:432. [PMID: 31796116 PMCID: PMC6892175 DOI: 10.1186/s12917-019-2184-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Accepted: 11/20/2019] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND African horse sickness (AHS) is a severe arthropod-borne viral disease of equids, with a mortality rate of up to 95% in susceptible naïve horses. Due to safety concerns with the current live, attenuated AHS vaccine, alternate safe and effective vaccination strategies such as virus-like particles (VLPs) are being investigated. Transient plant-based expression systems are a rapid and highly scalable means of producing such African horse sickness virus (AHSV) VLPs for vaccine purposes. RESULTS In this study, we demonstrated that transient co-expression of the four AHSV capsid proteins in agroinfiltrated Nicotiana benthamiana dXT/FT plants not only allowed for the assembly of homogenous AHSV-1 VLPs but also single, double and triple chimeric VLPs, where one capsid protein originated from one AHS serotype and at least one other capsid protein originated from another AHS serotype. Following optimisation of a large scale VLP purification procedure, the safety and immunogenicity of the plant-produced, triple chimeric AHSV-6 VLPs was confirmed in horses, the target species. CONCLUSIONS We have successfully shown assembly of single and double chimeric AHSV-7 VLPs, as well as triple chimeric AHSV-6 VLPs, in Nicotiana benthamiana dXT/FT plants. Plant produced chimeric AHSV-6 VLPs were found to be safe for administration into 6 month old foals as well as capable of eliciting a weak neutralizing humoral immune response in these target animals against homologous AHSV virus.
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Affiliation(s)
| | - Nobalanda B. Mokoena
- Onderstepoort Biological Products SOC Ltd, Private Bag X07, Onderstepoort, 0110 South Africa
| | | | - Vusi S. Dibakwane
- Onderstepoort Biological Products SOC Ltd, Private Bag X07, Onderstepoort, 0110 South Africa
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Porphyre T, Grewar JD. Assessing the potential of plains zebra to maintain African horse sickness in the Western Cape Province, South Africa. PLoS One 2019; 14:e0222366. [PMID: 31671099 PMCID: PMC6822716 DOI: 10.1371/journal.pone.0222366] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Accepted: 10/16/2019] [Indexed: 11/18/2022] Open
Abstract
African horse sickness (AHS) is a disease of equids that results in a non-tariff barrier to the trade of live equids from affected countries. AHS is endemic in South Africa except for a controlled area in the Western Cape Province (WCP) where sporadic outbreaks have occurred in the past 2 decades. There is potential that the presence of zebra populations, thought to be the natural reservoir hosts for AHS, in the WCP could maintain AHS virus circulation in the area and act as a year-round source of infection for horses. However, it remains unclear whether the epidemiology or the ecological conditions present in the WCP would enable persistent circulation of AHS in the local zebra populations. Here we developed a hybrid deterministic-stochastic vector-host compartmental model of AHS transmission in plains zebra (Equus quagga), where host populations are age- and sex-structured and for which population and AHS transmission dynamics are modulated by rainfall and temperature conditions. Using this model, we showed that populations of plains zebra present in the WCP are not sufficiently large for AHS introduction events to become endemic and that coastal populations of zebra need to be >2500 individuals for AHS to persist >2 years, even if zebras are infectious for more than 50 days. AHS cannot become endemic in the coastal population of the WCP unless the zebra population involves at least 50,000 individuals. Finally, inland populations of plains zebra in the WCP may represent a risk for AHS to persist but would require populations of at least 500 zebras or show unrealistic duration of infectiousness for AHS introduction events to become endemic. Our results provide evidence that the risk of AHS persistence from a single introduction event in a given plains zebra population in the WCP is extremely low and it is unlikely to represent a long-term source of infection for local horses.
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Affiliation(s)
- Thibaud Porphyre
- The Roslin Institute, University of Edinburgh, Edinburgh, Scotland, United Kingdom
- * E-mail:
| | - John D. Grewar
- South African Equine Health & Protocols NPC, Paardevlei, Cape Town, South Africa
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Calvo-Pinilla E, Gubbins S, Mertens P, Ortego J, Castillo-Olivares J. The immunogenicity of recombinant vaccines based on modified Vaccinia Ankara (MVA) viruses expressing African horse sickness virus VP2 antigens depends on the levels of expressed VP2 protein delivered to the host. Antiviral Res 2018; 154:132-139. [PMID: 29678552 PMCID: PMC5966619 DOI: 10.1016/j.antiviral.2018.04.015] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Revised: 04/13/2018] [Accepted: 04/17/2018] [Indexed: 12/17/2022]
Abstract
African horse sickness (AHS) is a lethal equine disease transmitted by Culicoides biting midges and caused by African horse sickness virus (AHSV). AHS is endemic to sub-Saharan Africa, but devastating outbreaks have been recorded periodically outside this region. The perceived risk of an AHS outbreak occurring in Europe has increased following the frequent epidemics caused in ruminants by bluetongue virus, closely related to AHSV. Attenuated vaccines for AHS are considered unsuitable for use in non-endemic countries due bio-safety concerns. Further, attenuated and inactivated vaccines are not compatible with DIVA (differentiate infected from vaccinated animals) strategies. All these factors stimulated the development of novel AHS vaccines that are safer, more efficacious and DIVA compatible. We showed previously that recombinant modified Vaccinia Ankara virus (MVA) vaccines encoding the outer capsid protein of AHSV (AHSV-VP2) induced virus neutralising antibodies (VNAb) and protection against AHSV in a mouse model and also in the horse. Passive immunisation studies demonstrated that immunity induced by MVA-VP2 was associated with pre-challenge VNAb titres in the vaccinates. Analyses of the inoculum of these MVA-VP2 experimental vaccines showed that they contained pre-formed AHSV-VP2. We continued studying the influence of pre-formed AHSV-VP2, present in the inoculum of MVA-VP2 vaccines, in the immunogenicity of MVA-VP2 vaccines. Thus, we compared correlates of immunity in challenged mice that were previously vaccinated with: a) MVA-VP2 (live); b) MVA-VP2 (live and sucrose gradient purified); c) MVA-VP2 (UV light inactivated); d) MVA-VP2 (UV light inactivated and diluted); e) MVA-VP2 (heat inactivated); f) MVA-VP2 (UV inactivated) + MVA-VP2 (purified); g) MVA-VP2 (heat inactivated) + MVA-VP2 (purified); and h) wild type-MVA (no insert). The results of these experiments showed that protection was maximal using MVA-VP2 (live) vaccine and that the protection conferred by all other vaccines correlated strongly with the levels of pre-formed AHSV-VP2 in the vaccine inoculum. MVA-VP2 vaccines (expressing African horse sickness virus VP2) induce protective immunity in mouse model and in horses. Experimental MVA-VP2 vaccines contain preformed AHSV-VP2 in the inoculum if they are not sucrose-gradient purified. MVA-VP2 vaccines express AHSV-VP2 in MVA-VP2 infected cells. Both pre-formed AHSV-VP2 and ‘de novo’ synthesised AHSV-VP2 in MVA-VP2 vaccinates contribute to MVA-VP2 immunogenicity.
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Affiliation(s)
- Eva Calvo-Pinilla
- The Pirbright Institute, Ash Road, Pirbright, Surrey, GU24 0NF, UK; INIA-CISA, 28130, Valdeolmos, Madrid, Spain
| | - Simon Gubbins
- The Pirbright Institute, Ash Road, Pirbright, Surrey, GU24 0NF, UK
| | - Peter Mertens
- The Pirbright Institute, Ash Road, Pirbright, Surrey, GU24 0NF, UK
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Manning NM, Bachanek-Bankowska K, Mertens PPC, Castillo-Olivares J. Vaccination with recombinant Modified Vaccinia Ankara (MVA) viruses expressing single African horse sickness virus VP2 antigens induced cross-reactive virus neutralising antibodies (VNAb) in horses when administered in combination. Vaccine 2017; 35:6024-6029. [DOI: 10.1016/j.vaccine.2017.04.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 03/27/2017] [Accepted: 04/04/2017] [Indexed: 12/11/2022]
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Robin M, Page P, Archer D, Baylis M. African horse sickness: The potential for an outbreak in disease-free regions and current disease control and elimination techniques. Equine Vet J 2016; 48:659-69. [PMID: 27292229 DOI: 10.1111/evj.12600] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 06/09/2016] [Indexed: 11/26/2022]
Abstract
African horse sickness (AHS) is an arboviral disease of equids transmitted by Culicoides biting midges. The virus is endemic in parts of sub-Saharan Africa and official AHS disease-free status can be obtained from the World Organization for Animal Health on fulfilment of a number of criteria. AHS is associated with case fatality rates of up to 95%, making an outbreak among naïve horses both a welfare and economic disaster. The worldwide distributions of similar vector-borne diseases (particularly bluetongue disease of ruminants) are changing rapidly, probably due to a combination of globalisation and climate change. There is extensive evidence that the requisite conditions for an AHS epizootic currently exist in disease-free countries. In particular, although the stringent regulations enforced upon competition horses make them extremely unlikely to redistribute the virus, there are great concerns over the effects of illegal equid movement. An outbreak of AHS in a disease free region would have catastrophic effects on equine welfare and industry, particularly for international events such as the Olympic Games. While many regions have contingency plans in place to manage an outbreak of AHS, further research is urgently required if the equine industry is to avoid or effectively contain an AHS epizootic in disease-free regions. This review describes the key aspects of AHS as a global issue and discusses the evidence supporting concerns that an epizootic may occur in AHS free countries, the planned government responses, and the roles and responsibilities of equine veterinarians.
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Affiliation(s)
- M Robin
- Department of Epidemiology and Population Health, Institute of Infection and Global Health, University of Liverpool, Leahurst, Neston, Cheshire, UK
| | - P Page
- Department of Companion Animal Clinical Studies, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa
| | - D Archer
- Department of Epidemiology and Population Health, Institute of Infection and Global Health, University of Liverpool, Leahurst, Neston, Cheshire, UK
| | - M Baylis
- Department of Epidemiology and Population Health, Institute of Infection and Global Health, University of Liverpool, Leahurst, Neston, Cheshire, UK.,NIHR Health Protection Research Unit in Emerging and Zoonotic Infections, University of Liverpool, UK
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10
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Faber F, van Kleef M, Tshilwane S, Pretorius A. African horse sickness virus serotype 4 antigens, VP1-1, VP2-2, VP4, VP7 and NS3, induce cytotoxic T cell responses in vitro. Virus Res 2016; 220:12-20. [DOI: 10.1016/j.virusres.2016.04.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Revised: 04/06/2016] [Accepted: 04/06/2016] [Indexed: 02/03/2023]
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VP2 Exchange and NS3/NS3a Deletion in African Horse Sickness Virus (AHSV) in Development of Disabled Infectious Single Animal Vaccine Candidates for AHSV. J Virol 2015; 89:8764-72. [PMID: 26063433 PMCID: PMC4524073 DOI: 10.1128/jvi.01052-15] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Accepted: 06/04/2015] [Indexed: 01/07/2023] Open
Abstract
African horse sickness virus (AHSV) is a virus species in the genus Orbivirus of the family Reoviridae. There are nine serotypes of AHSV showing different levels of cross neutralization. AHSV is transmitted by species of Culicoides biting midges and causes African horse sickness (AHS) in equids, with a mortality rate of up to 95% in naive horses. AHS has become a serious threat for countries outside Africa, since endemic Culicoides species in moderate climates appear to be competent vectors for the related bluetongue virus (BTV). To control AHS, live-attenuated vaccines (LAVs) are used in Africa. We used reverse genetics to generate “synthetic” reassortants of AHSV for all nine serotypes by exchange of genome segment 2 (Seg-2). This segment encodes VP2, which is the serotype-determining protein and the dominant target for neutralizing antibodies. Single Seg-2 AHSV reassortants showed similar cytopathogenic effects in mammalian cells but displayed different growth kinetics. Reverse genetics for AHSV was also used to study Seg-10 expressing NS3/NS3a proteins. We demonstrated that NS3/NS3a proteins are not essential for AHSV replication in vitro. NS3/NS3a of AHSV is, however, involved in the cytopathogenic effect in mammalian cells and is very important for virus release from cultured insect cells in particular. Similar to the concept of the bluetongue disabled infectious single animal (BT DISA) vaccine platform, an AHS DISA vaccine platform lacking NS3/NS3a expression was developed. Using exchange of genome segment 2 encoding VP2 protein (Seg-2[VP2]), we will be able to develop AHS DISA vaccine candidates for all current AHSV serotypes. IMPORTANCE African horse sickness virus is transmitted by species of Culicoides biting midges and causes African horse sickness in equids, with a mortality rate of up to 95% in naive horses. African horse sickness has become a serious threat for countries outside Africa, since endemic Culicoides species in moderate climates are supposed to be competent vectors. By using reverse genetics, viruses of all nine serotypes were constructed by the exchange of Seg-2 expressing the serotype-determining VP2 protein. Furthermore, we demonstrated that the nonstructural protein NS3/NS3a is not essential for virus replication in vitro. However, the potential spread of the virus by biting midges is supposed to be blocked, since the in vitro release of the virus was strongly reduced due to this deletion. VP2 exchange and NS3/NS3a deletion in African horse sickness virus were combined in the concept of a disabled infectious single animal vaccine for all nine serotypes.
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12
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Kanai Y, van Rijn PA, Maris-Veldhuis M, Kaname Y, Athmaram TN, Roy P. Immunogenicity of recombinant VP2 proteins of all nine serotypes of African horse sickness virus. Vaccine 2014; 32:4932-7. [PMID: 25045805 PMCID: PMC4148702 DOI: 10.1016/j.vaccine.2014.07.031] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Revised: 06/19/2014] [Accepted: 07/08/2014] [Indexed: 12/02/2022]
Abstract
African horse sickness (AHS) is an equine disease with a mortality of up to 90% for susceptible horses. The causative agent AHS virus (AHSV) is transmitted by species of Culicoides. AHSV serogroup within the genus Orbivirus of the Reoviridae family consists of nine serotypes that show no or very limited cross-neutralization. Of the seven structural proteins (VP1-VP7) of AHSV, VP2 is the serotype specific protein, and the major target for neutralizing antibodies. In this report, recombinant VP2 proteins of all nine serotypes were expressed individually by the baculovirus expression system and the immunogenicity of each was studied by immunization of guinea pigs with single VP2 as well as with cocktails of VP2 proteins. Homologous neutralizing antibodies measured by 50% plaque reduction assay showed varying degrees (from 37 to 1365) of titers for different VP2 proteins. A low cross-neutralizing antibody titer was found for genetically related AHSV serotypes. Immunization with VP2 cocktails containing equal amounts of each of the VP2 proteins also triggered neutralizing antibodies albeit to lower titers (4-117) to each of the serotypes in the cocktail. This study is a first step to develop a VP2 subunit vaccine for AHS and our results indicate that VP2 subunit vaccines are feasible individually or in a multi-serotype cocktail.
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Affiliation(s)
- Yuta Kanai
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, United Kingdom
| | - Piet A van Rijn
- Department of Virology, Central Veterinary Institute of Wageningen University (CVI), PO Box 65, 8200 AB Lelystad, The Netherlands; Department of Biochemistry, Centre for Human Metabonomics, North-West University, Private Bag X6001, Potchefstroom 2520, South Africa
| | - Mieke Maris-Veldhuis
- Department of Virology, Central Veterinary Institute of Wageningen University (CVI), PO Box 65, 8200 AB Lelystad, The Netherlands
| | - Yuki Kaname
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, United Kingdom
| | - T N Athmaram
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, United Kingdom
| | - Polly Roy
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, United Kingdom.
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Alberca B, Bachanek-Bankowska K, Cabana M, Calvo-Pinilla E, Viaplana E, Frost L, Gubbins S, Urniza A, Mertens P, Castillo-Olivares J. Vaccination of horses with a recombinant modified vaccinia Ankara virus (MVA) expressing African horse sickness (AHS) virus major capsid protein VP2 provides complete clinical protection against challenge. Vaccine 2014; 32:3670-4. [PMID: 24837765 PMCID: PMC4061461 DOI: 10.1016/j.vaccine.2014.04.036] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Revised: 04/01/2014] [Accepted: 04/14/2014] [Indexed: 11/15/2022]
Abstract
A recombinant modified Vaccinia Ankara virus expressing VP2 of African horse sickness virus serotype 9 was generated. Four horses were vaccinated on days 0 and 20. Three unvaccinated controls were used. Vaccinated and control horses were challenged intravenously with 107.4TCID50 of AHSV-9 on day 34 of the study. At challenge, vaccinates had virus neutralising antibodies but were negative for antibodies to AHSV-VP7. All vaccinates were completely protected against clinical signs of African horse sickness.
African horse sickness virus (AHSV) is an arthropod-borne pathogen that infects all species of equidae and causes high mortality in horses. Previously, a recombinant modified vaccinia Ankara (MVA) virus expressing the protein VP2 of AHSV serotype 4 was shown to induce virus neutralising antibodies in horses and protected interferon alpha receptor gene knock-out mice (IFNAR −/−) against virulent AHSV challenge. This study builds on the previous work, examining the protective efficacy of MVA-VP2 vaccination in the natural host of AHSV infection. A study group of 4 horses was vaccinated twice with a recombinant MVA virus expressing the major capsid protein (VP2) of AHSV serotype 9. Vaccinated animals and a control group of unvaccinated horses were then challenged with a virulent strain of AHSV-9. The vaccinated animals were completely protected against clinical disease and also against viraemia as measured by standard end-point dilution assays. In contrast, all control horses presented viraemia after challenge and succumbed to the infection. These results demonstrate the potential of recombinant MVA viruses expressing the outer capsid VP2 of AHSV as a protective vaccine against AHSV infection in the field.
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Affiliation(s)
- Berta Alberca
- Zoetis-Spain, Ctra de Comprodon, Finca La Riba, 17813 Vall de Bianya, Girona, Spain
| | | | - Marta Cabana
- Zoetis-Spain, Ctra de Comprodon, Finca La Riba, 17813 Vall de Bianya, Girona, Spain
| | - Eva Calvo-Pinilla
- The Pirbright Institute, Ash Road, Pirbright, Woking GU24 0NF, Surrey, UK
| | - Elisenda Viaplana
- Zoetis-Spain, Ctra de Comprodon, Finca La Riba, 17813 Vall de Bianya, Girona, Spain
| | - Lorraine Frost
- The Pirbright Institute, Ash Road, Pirbright, Woking GU24 0NF, Surrey, UK
| | - Simon Gubbins
- The Pirbright Institute, Ash Road, Pirbright, Woking GU24 0NF, Surrey, UK
| | - Alicia Urniza
- Zoetis-Spain, Ctra de Comprodon, Finca La Riba, 17813 Vall de Bianya, Girona, Spain
| | - Peter Mertens
- The Pirbright Institute, Ash Road, Pirbright, Woking GU24 0NF, Surrey, UK
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Calvo-Pinilla E, de la Poza F, Gubbins S, Mertens PPC, Ortego J, Castillo-Olivares J. Vaccination of mice with a modified Vaccinia Ankara (MVA) virus expressing the African horse sickness virus (AHSV) capsid protein VP2 induces virus neutralising antibodies that confer protection against AHSV upon passive immunisation. Virus Res 2014; 180:23-30. [PMID: 24333835 DOI: 10.1016/j.virusres.2013.12.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2013] [Revised: 11/29/2013] [Accepted: 12/02/2013] [Indexed: 12/26/2022]
Abstract
In previous studies we showed that a recombinant Modified Vaccinia Ankara (MVA) virus expressing the protein VP2 of AHSV serotype 4 (MVA-VP2) induced virus neutralising antibodies in horses and protected interferon alpha receptor gene knock-out mice (IFNAR-/-) against challenge. We continued these studies and determined, in the IFNAR-/- mouse model, whether the antibody responses induced by MVA-VP2 vaccination play a key role in protection against AHSV. Thus, groups of mice were vaccinated with wild type MVA (MVA-wt) or MVA-VP2 and the antisera from these mice were used in a passive immunisation experiment. Donor antisera from (a) MVA-wt; (b) MVA-VP2 vaccinated; or (c) MVA-VP2 vaccinated and AHSV infected mice, were transferred to AHSV non-immune recipient mice. The recipients were challenged with virulent AHSV together with MVA-VP2 vaccinated and MVA-wt vaccinated control animals and the levels of protection against AHSV-4 were compared between all these groups. The results showed that following AHSV challenge, mice that were passively immunised with MVA-VP2 vaccinated antisera were highly protected against AHSV disease and had lower levels of viraemia than recipients of MVA-wt antisera. Our study indicates that MVA-VP2 vaccination induces a highly protective humoral immune response against AHSV.
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Affiliation(s)
| | | | - Simon Gubbins
- The Pirbright Institute, Pirbright, Woking, Surrey, United Kingdom
| | | | - Javier Ortego
- Centro de Investigación en Sanidad Animal, CISA-INIA, Valdeolmos, Madrid, Spain
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El Garch H, Crafford JE, Amouyal P, Durand PY, Edlund Toulemonde C, Lemaitre L, Cozette V, Guthrie A, Minke JM. An African horse sickness virus serotype 4 recombinant canarypox virus vaccine elicits specific cell-mediated immune responses in horses. Vet Immunol Immunopathol 2012; 149:76-85. [PMID: 22763149 DOI: 10.1016/j.vetimm.2012.06.009] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2011] [Revised: 05/30/2012] [Accepted: 06/06/2012] [Indexed: 12/24/2022]
Abstract
A recombinant canarypox virus vectored vaccine co-expressing synthetic genes encoding outer capsid proteins, VP2 and VP5, of African horse sickness virus (AHSV) serotype 4 (ALVAC(®)-AHSV4) has been demonstrated to fully protect horses against homologous challenge with virulent field virus. Guthrie et al. (2009) detected weak and variable titres of neutralizing antibody (ranging from <10 to 40) 8 weeks after vaccination leading us to hypothesize that there could be a participation of cell mediated immunity (CMI) in protection against AHSV4. The present study aimed at characterizing the CMI induced by the experimental ALVAC(®)-AHSV4 vaccine. Six horses received two vaccinations twenty-eight days apart and three horses remained unvaccinated. The detection of VP2/VP5 specific IFN-γ responses was assessed by enzyme linked immune spot (ELISpot) assay and clearly demonstrated that all ALVAC(®)-AHSV4 vaccinated horses developed significant IFN-γ production compared to unvaccinated horses. More detailed immune responses obtained by flow cytometry demonstrated that ALVAC(®)-AHSV4 vaccinations induced immune cells, mainly CD8(+) T cells, able to recognize multiple T-epitopes through all VP2 and only the N-terminus sequence of VP5. Neither VP2 nor VP5 specific IFN-γ responses were detected in unvaccinated horses. Overall, our data demonstrated that an experimental recombinant canarypox based vaccine induced significant CMI specific for both VP2 and VP5 proteins of AHSV4.
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Backer JA, Nodelijk G. Transmission and control of African horse sickness in The Netherlands: a model analysis. PLoS One 2011; 6:e23066. [PMID: 21850252 PMCID: PMC3151287 DOI: 10.1371/journal.pone.0023066] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2011] [Accepted: 07/08/2011] [Indexed: 11/24/2022] Open
Abstract
African horse sickness (AHS) is an equine viral disease that is spread by Culicoides spp. Since the closely related disease bluetongue established itself in The Netherlands in 2006, AHS is considered a potential threat for the Dutch horse population. A vector-host model that incorporates the current knowledge of the infection biology is used to explore the effect of different parameters on whether and how the disease will spread, and to assess the effect of control measures. The time of introduction is an important determinant whether and how the disease will spread, depending on temperature and vector season. Given an introduction in the most favourable and constant circumstances, our results identify the vector-to-host ratio as the most important factor, because of its high variability over the country. Furthermore, a higher temperature accelerates the epidemic, while a higher horse density increases the extent of the epidemic. Due to the short infectious period in horses, the obvious clinical signs and the presence of non-susceptible hosts, AHS is expected to invade and spread less easily than bluetongue. Moreover, detection is presumed to be earlier, which allows control measures to be targeted towards elimination of infection sources. We argue that recommended control measures are euthanasia of infected horses with severe clinical signs and vector control in infected herds, protecting horses from midge bites in neighbouring herds, and (prioritized) vaccination of herds farther away, provided that transport regulations are strictly applied. The largest lack of knowledge is the competence and host preference of the different Culicoides species present in temperate regions.
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Affiliation(s)
- Jantien A Backer
- Department of Epidemiology, Crisis Organisation and Diagnostics, Central Veterinary Institute of Wageningen UR, Lelystad, The Netherlands.
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In vivo cross-protection to African horse sickness Serotypes 5 and 9 after vaccination with Serotypes 8 and 6. Vaccine 2010; 28:6505-17. [PMID: 20638456 DOI: 10.1016/j.vaccine.2010.06.105] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2009] [Revised: 06/08/2010] [Accepted: 06/30/2010] [Indexed: 11/23/2022]
Abstract
The polyvalent African horsesickness (AHS) attenuated live virus (AHS-ALV) vaccine produced at Onderstepoort Biological Products incorporates 7 of the 9 known serotypes circulating in southern Africa. Serological cross-reaction has been shown in vitro to Serotypes 5 and 9 by Serotypes 8 and 6 respectively, but the degree of in vivo cross-protection between these serotypes in vaccinated horses has not previously been reported. Due to the increasing incidence of AHS Serotypes 5 and 9 in the field, over the last 3-4 seasons of AHS in South Africa, and the absence of Serotypes 5 and 9 in the AHS-ALV vaccine, it was necessary to conduct a vaccination-challenge study to determine in vivo cross-protection of vaccine-incorporated Serotypes 8 and 6 respectively. Groups of horses were vaccinated with either the polyvalent AHS-ALV vaccine or a monovalent Serotype 6 (vAHSV6) or 8 (vAHSV8) vaccine to determine the cross-protection of vaccinated horses following challenge with virulent AHS virus (AHSV) of either Serotype 5, 6, 8 or 9. Serial vaccination of naive horses with the polyvalent AHS-ALV vaccine generated a broad neutralizing antibody response to all vaccine strains as well as cross-neutralizing antibodies to Serotypes 5 and 9. Booster vaccination of horses with monovalent vaccine vAHSV6 or vAHSV8 induced an adequate protective immune response to challenge with homologous and heterologous virulent virus. In vivo cross-protection between AHSV6 and AHSV9 and AHSV8 and AHSV5 respectively, was demonstrated.
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Chiam R, Sharp E, Maan S, Rao S, Mertens P, Blacklaws B, Davis-Poynter N, Wood J, Castillo-Olivares J. Induction of antibody responses to African horse sickness virus (AHSV) in ponies after vaccination with recombinant modified vaccinia Ankara (MVA). PLoS One 2009; 4:e5997. [PMID: 19543394 PMCID: PMC2694985 DOI: 10.1371/journal.pone.0005997] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2008] [Accepted: 05/23/2009] [Indexed: 11/18/2022] Open
Abstract
Background African horse sickness virus (AHSV) causes a non-contagious, infectious disease in equids, with mortality rates that can exceed 90% in susceptible horse populations. AHSV vaccines play a crucial role in the control of the disease; however, there are concerns over the use of polyvalent live attenuated vaccines particularly in areas where AHSV is not endemic. Therefore, it is important to consider alternative approaches for AHSV vaccine development. We have carried out a pilot study to investigate the ability of recombinant modified vaccinia Ankara (MVA) vaccines expressing VP2, VP7 or NS3 genes of AHSV to stimulate immune responses against AHSV antigens in the horse. Methodology/Principal Findings VP2, VP7 and NS3 genes from AHSV-4/Madrid87 were cloned into the vaccinia transfer vector pSC11 and recombinant MVA viruses generated. Antigen expression or transcription of the AHSV genes from cells infected with the recombinant viruses was confirmed. Pairs of ponies were vaccinated with MVAVP2, MVAVP7 or MVANS3 and both MVA vector and AHSV antigen-specific antibody responses were analysed. Vaccination with MVAVP2 induced a strong AHSV neutralising antibody response (VN titre up to a value of 2). MVAVP7 also induced AHSV antigen–specific responses, detected by western blotting. NS3 specific antibody responses were not detected. Conclusions This pilot study demonstrates the immunogenicity of recombinant MVA vectored AHSV vaccines, in particular MVAVP2, and indicates that further work to investigate whether these vaccines would confer protection from lethal AHSV challenge in the horse is justifiable.
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Affiliation(s)
- Rachael Chiam
- Animal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk, United Kingdom
| | - Emma Sharp
- Animal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk, United Kingdom
| | - Sushila Maan
- Institute for Animal Health, Pirbright Laboratory, Pirbright, Surrey, United Kingdom
| | - Shujing Rao
- Institute for Animal Health, Pirbright Laboratory, Pirbright, Surrey, United Kingdom
| | - Peter Mertens
- Institute for Animal Health, Pirbright Laboratory, Pirbright, Surrey, United Kingdom
| | - Barbara Blacklaws
- Cambridge Infectious Diseases Consortium, Department of Veterinary Medicine, Cambridge, United Kingdom
| | - Nick Davis-Poynter
- Sir Albert Sakzewski Virus Research Centre, University of Queensland, Herston, Queensland, Australia
| | - James Wood
- Cambridge Infectious Diseases Consortium, Department of Veterinary Medicine, Cambridge, United Kingdom
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Bougrine SI, Fihri OF, Fehri MM. Western immunoblotting as a method for the detection of African horse sickness virus protein-specific antibodies: differentiation between infected and vaccinated horses. ARCHIVES OF VIROLOGY. SUPPLEMENTUM 1998; 14:329-36. [PMID: 9785518 DOI: 10.1007/978-3-7091-6823-3_29] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
A Western immunoblotting procedure has been developed for the detection of African horse sickness virus (AHSV) protein-specific antibody responses. This assay readily identifies antibodies specific for at least 4 distinct, AHSV proteins, including VP5, NS1, NS2 and NS3/NS3a. By using the AHSV non-structural proteins as 'markers', the Western blotting procedure could be employed to provide a reliable means of discriminating between animals vaccinated with a purified, inactivated AHSV vaccine and those either naturally infected or vaccinated with a live, attenuated AHSV vaccine.
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Affiliation(s)
- S I Bougrine
- Département de Microbiologie Immunologie Maladies Contagieuses, Institut Agronomique et Vétérinaire Hassan II, Rabat, Morocco
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House JA. Future international management of African horse sickness vaccines. ARCHIVES OF VIROLOGY. SUPPLEMENTUM 1998; 14:297-304. [PMID: 9785514 DOI: 10.1007/978-3-7091-6823-3_25] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Three types of African horse sickness (AHS) vaccine, namely adult mouse brain, modified live vaccine and inactivated viral vaccine (IVV) are reviewed. The results of efficacy trials carried out with each vaccine type highlight the advantages of the IVV. Vaccination with African horse sickness virus serotype 4 IVV, given as 2 separate doses, provided full protection against subsequent, homologous challenge. The absence of any detectable viraemia after challenge would also prevent infection of insect vectors. The advantages of establishing international vaccine banks for AHS are discussed.
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Affiliation(s)
- J A House
- USDA, Animal and Plant Health Inspection Service, Greenport, New York, USA
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Laviada MD, Roy P, Sánchez-Vizcaíno JM, Casal JI. The use of African horse sickness virus NS3 protein, expressed in bacteria, as a marker to differentiate infected from vaccinated horses. Virus Res 1995; 38:205-18. [PMID: 8578859 DOI: 10.1016/0168-1702(95)00061-t] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Segment 10 of the double-stranded RNA (dsRNA) genome from African horse sickness virus serotype 4 (AHSV-4) was cloned and sequenced. The sequence of the coding region showed a total length of 667 bp. Nucleotide comparisons showed a 95% sequence similarity between serotypes 4 and 9, and 76% between serotypes 4 and 3. cDNA clones containing the coding region were cloned in the vector pET3xb and expressed in Escherichia coli. The NS3 gene product was synthesised at very high level as an insoluble fusion protein. The recombinant protein was used in a differential ELISA to distinguish horses that were infected with AHSV-4 or vaccinated with live-modified virus from those vaccinated with a purified inactivated vaccine. The results obtained indicate that recombinant NS3 can indeed differentiate between infected and vaccinated animals implying that this recombinant could be developed as a diagnostic reagent, and it would allow the mobility of vaccinated horses. Thus, economical losses associated with this disease could be avoided.
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Affiliation(s)
- M D Laviada
- Centro de Investigación en Sanidad Animal, CISA-INIA, Valdeolmos, Madrid, Spain
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