Equine herpesvirus type 2 (EHV-2) as a predisposing factor for Rhodococcus equi pneumonia in foals: prevention of the bifactorial disease with EHV-2 immunostimulating complexes.
Abstract: Equine herpesvirus type 2 (EHV-2), a member of the Gammaherpesvirinae subfamily, was studied in a two-phase respiratory disease complex of young foals as a predisposing factor for the secondary bacterial invasion of lungs with Rhodococcus equi (R. equi). Foals were immunized against EHV-2 on a farm where R. equi pneumonia regularly occurred during the last years. The immunizations were performed by using a subunit vaccine which selectively presents envelope glycoproteins of EHV-2 in a multimeric form of immunostimulating complexes (iscoms). The etiological role of EHV-2 was estimated by observing the occurrence of the respiratory disease complex in groups of foals immunized against the virus, in comparison to non-immunized controls. The immunization trials of young animals revealed that the iscom subunit vaccine formulation is able to overcome the interference of maternal antibodies. Active immunization of foals with a single dose of the iscoms provided a certain degree of protection, while two injections of iscoms yielded complete protection against the disease complex in the majority of the treated animals, by preventing the manifestation of R. equi pneumonia. The present findings strongly support the hypothesis that EHV-2 is a predisposing factor for the R. equi invasion of the respiratory tract. The EHV-2 iscom formulation provides highly specific and effective means to prevent the disease complex.
Publication Date: 1996-07-01 PubMed ID: 8828122DOI: 10.1016/0378-1135(96)00032-6Google Scholar: Lookup
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- Journal Article
- Research Support
- Non-U.S. Gov't
Summary
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The research investigated the role of Equine herpesvirus type 2 (EHV-2) as a contributing factor to Rhodococcus equi pneumonia in foals and found that immunizing against EHV-2 could effectively prevent the disease complex.
Study Overview
The study delved into the respiratory disease complex in foals that was believed to be influenced by the presence of Equine herpesvirus type 2 (EHV-2). The research was centred around the claim that EHV-2 infection in foals made them more susceptible to a secondary bacterial invasion by Rhodococcus equi (R. equi), leading to the development of pneumonia.
Evaluating the Role of EHV-2
- The researchers aimed to determine the role of EHV-2 by observing the occurrence of the respiratory disease complex in foals immunized against EHV-2 and comparing it to a control group of foals that were not immunized.
- For the immunization, a subunit vaccine was used that selectively presents the envelope glycoproteins of EHV-2 in a multimeric form known as immunostimulating complexes (ISCOMs).
Immunization Findings
- The vaccine trials showed that the ISCOM subunit formulation was capable of overcoming the interference from maternal antibodies in foals.
- A single dose of the ISCOMs vaccine provided some degree of protection to the foals. However, two injections offered full protection against the respiratory disease complex to most of the treated animals.
- Effectively, the symptom manifestation of R. equi pneumonia was prevented with the ISCOMs immunization, buttressing the idea that EHV-2 was a key contributing factor for the R. equi invasion of the respiratory tract in foals.
Conclusion
This study projects EHV-2 as a significant factor for susceptibility to R. equi pneumonia in young foals. The research findings also accentuate the potential of the EHV-2 ISCOM formulation as a highly specific and effective preventive measure against the disease.
Cite This Article
APA
Nordengrahn A, Rusvai M, Merza M, Ekström J, Morein B, Belák S.
(1996).
Equine herpesvirus type 2 (EHV-2) as a predisposing factor for Rhodococcus equi pneumonia in foals: prevention of the bifactorial disease with EHV-2 immunostimulating complexes.
Vet Microbiol, 51(1-2), 55-68.
https://doi.org/10.1016/0378-1135(96)00032-6 Publication
Researcher Affiliations
- Department of Virology, National Veterinary Institute, Uppsala, Sweden.
MeSH Terms
- Actinomycetales Infections / etiology
- Actinomycetales Infections / microbiology
- Actinomycetales Infections / prevention & control
- Actinomycetales Infections / veterinary
- Animals
- Herpesviridae / immunology
- Herpesviridae Infections / complications
- Herpesviridae Infections / microbiology
- Herpesviridae Infections / prevention & control
- Herpesviridae Infections / veterinary
- Horse Diseases / immunology
- Horse Diseases / microbiology
- Horse Diseases / prevention & control
- Horses
- ISCOMs / administration & dosage
- ISCOMs / chemistry
- Mice
- Mice, Inbred BALB C
- Pilot Projects
- Pneumonia, Bacterial / etiology
- Pneumonia, Bacterial / microbiology
- Pneumonia, Bacterial / prevention & control
- Pneumonia, Bacterial / veterinary
- Rhodococcus equi
- Viral Vaccines / administration & dosage
Citations
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