Strangvac: A recombinant fusion protein vaccine that protects against strangles, caused by Streptococcus equi.
Abstract: The host-restricted pathogen Streptococcus equi causes strangles in the horse, which is characterised by abscessation of the lymph nodes of the head and neck. The disease is endemic throughout the world causing considerable welfare and economic cost to the horse industry. Here we report the results of three studies where ponies were vaccinated with combinations of recombinant fusion proteins to optimise vaccine production and the level of protection conferred. Optimal protection was conferred by a prototype multicomponent subunit vaccine, Strangvac 4, which contained eight proteins CNE, SclC, SclF, SclI, EAG (fused as CCE), SEQ_402, SEQ_0256 (fused as Eq85) and IdeE. Across the three experiments only three of 16 ponies vaccinated with Strangvac 4 became pyretic compared to all 16 placebo-vaccinated control ponies (P < .001). S. equi was recovered from the lymph nodes of eight Strangvac 4-vaccinated and 15 control ponies (P = .016). None of the ponies vaccinated with Strangvac 4, or the other prototype vaccines developed adverse reactions following vaccination. Our data provide evidence in support of the further clinical development of the Strangvac 4 vaccine.
Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.
Publication Date: 2018-02-02 PubMed ID: 29398274DOI: 10.1016/j.vaccine.2018.01.030Google Scholar: Lookup
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- Journal Article
Summary
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The article discusses a successful experimental vaccine, Strangvac 4, which provides protection against Streptococcus equi, a pathogen that causes a serious equine disease known as strangles.
Introduction
- Streptococcus equi is a pathogen that affects horses, leading to a disease called strangles. This disease, characterized by lymph node abscesses in the head and neck, is prevalent worldwide and poses significant welfare and financial issues for the horse industry.
- The researchers conducted three studies testing different combinations of recombinant fusion proteins in order to enhance vaccine production and the levels of protection provided.
Strangvac 4: A Prototypical subunit vaccine
- The optimal protection against the disease was provided by a prototype subunit vaccine named Strangvac 4. This vaccine is a composition of eight proteins – CNE, SclC, SclF, SclI, EAG, SEQ_402, SEQ_0256, and IdeE.
- In the experiments, Strangvac 4 showed promising results, with only three out of the 16 vaccinated ponies becoming feverish, compared to all 16 control group ponies. Furthermore, S. equi was detected in the lymph nodes of eight vaccinated ponies, compared to 15 from the control group.
Adverse Reactions and Further Development
- Remarkably, none of the ponies that were vaccinated with Strangvac 4, or other prototype vaccines, showed adverse reactions following vaccination, suggesting a high safety profile.
- The researchers’ data and findings promote the further clinical development of Strangvac 4. This vaccine, if further developed and approved, may provide a much-needed solution to the welfare and economic issues caused by the equine disease strangles.
Cite This Article
APA
Robinson C, Frykberg L, Flock M, Guss B, Waller AS, Flock JI.
(2018).
Strangvac: A recombinant fusion protein vaccine that protects against strangles, caused by Streptococcus equi.
Vaccine, 36(11), 1484-1490.
https://doi.org/10.1016/j.vaccine.2018.01.030 Publication
Researcher Affiliations
- Department of Bacteriology, Animal Health Trust, Lanwades Park, Kentford, Newmarket CB8 7UU, UK. Electronic address: carl.robinson@aht.org.uk.
- Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, P.O. Box 7036, SE-750 07 Uppsala, Sweden.
- Department of Microbiology, Tumor and Cellbiology, Karolinska Institutet, P.O. Box 280, SE-171 77 Stockholm, Sweden.
- Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, P.O. Box 7036, SE-750 07 Uppsala, Sweden.
- Department of Bacteriology, Animal Health Trust, Lanwades Park, Kentford, Newmarket CB8 7UU, UK.
- Department of Microbiology, Tumor and Cellbiology, Karolinska Institutet, P.O. Box 280, SE-171 77 Stockholm, Sweden; Intervacc AB, PO Box 112, SE-129 22 Hägersten, Sweden.
MeSH Terms
- Animals
- Biomarkers
- Horse Diseases / diagnosis
- Horse Diseases / immunology
- Horse Diseases / prevention & control
- Horses
- Immunization
- Immunization Schedule
- Leukocyte Count
- Outcome Assessment, Health Care
- Recombinant Fusion Proteins / immunology
- Streptococcal Infections / veterinary
- Streptococcal Vaccines / administration & dosage
- Streptococcal Vaccines / immunology
- Streptococcus equi / immunology
- Vaccines, Synthetic / administration & dosage
- Vaccines, Synthetic / immunology
Citations
This article has been cited 7 times.- He L, Khine NO, Song J, Loubière C, Butaye P. Geographic diversity of the Streptococcus equi subsp. equi accessory genome: implications for vaccines and global surveillance. Front Vet Sci 2025;12:1721958.
- Gröndahl G, Righetti F, Aspán A, Bjerketorp J, Frosth S, Frykberg L, Jacobsson K, Guss B, Paillot R, Flock JI, Henriques-Normark B, Waller AS. Reining in strangles: Absence of disease in horses vaccinated with a DIVA-compatible recombinant fusion protein vaccine, Strangvac, following natural exposure to Streptococcus equi subspecies equi. Equine Vet J 2026 Mar;58(2):476-485.
- Righetti F, Hentrich K, Flock M, Frosth S, Jacobsson K, Bjerketorp J, Pathak A, Ido N, Henriques-Normark B, Frykberg L, Paillot R, Guss B, Wood T, Flock JI, Waller AS. Neutralisation of the Immunoglobulin-Cleaving Activity of Streptococcus equi Subspecies equi IdeE by Blood Sera from Ponies Vaccinated with a Multicomponent Protein Vaccine. Vaccines (Basel) 2025 Oct 17;13(10).
- Abbasi E. Immunology of vector-borne diseases: the role of immunopharmacology in controlling viral and parasitic infections. BMC Infect Dis 2025 Sep 29;25(1):1182.
- Rotinsulu DA, Ewers C, Kerner K, Amrozi A, Soejoedono RD, Semmler T, Bauerfeind R. Molecular Features and Antimicrobial Susceptibilities of Streptococcus equi ssp. equi Isolates from Strangles Cases in Indonesia. Vet Sci 2023 Jan 10;10(1).
- Dominguez-Medina CC, Rash NL, Robillard S, Robinson C, Efstratiou A, Broughton K, Parkhill J, Holden MTG, Lopez-Alvarez MR, Paillot R, Waller AS. SpeS: A Novel Superantigen and Its Potential as a Vaccine Adjuvant against Strangles. Int J Mol Sci 2020 Jun 23;21(12).
- Charbonneau ARL, Taylor E, Mitchell CJ, Robinson C, Cain AK, Leigh JA, Maskell DJ, Waller AS. Identification of genes required for the fitness of Streptococcus equi subsp. equi in whole equine blood and hydrogen peroxide. Microb Genom 2020 Apr;6(4).
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