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Debra Elton - One of the best experts on this subject based on the ideXlab platform.
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An efficient genome sequencing method for Equine Influenza [H3N8] virus reveals a new polymorphism in the PA-X protein
Virology Journal, 2014Co-Authors: Adam Rash, Alana Woodward, Neil Bryant, John Mccauley, Debra EltonAbstract:Background H3N8 Equine Influenza virus (EIV) has caused disease outbreaks in horses across the world since its first isolation in 1963. However, unlike human, swine and avian Influenza, there is relatively little sequence data available for this virus. The majority of published sequences are for the segment encoding haemagglutinin (HA), one of the two surface glycoproteins, making it difficult to study the evolution of the other gene segments and determine the level of reassortment occurring between sub-lineages. Methods To facilitate the generation of full genome sequences for EIV, we developed a simple, cost-effective and efficient method. M13-tagged primers were used to amplify short, overlapping RT-PCR products, which were then sequenced using Sanger dideoxynucleotide sequencing technology. We also modified a previously published method, developed for human H3N2 and avian H5N1 Influenza viruses, which was based on the ligation of viral RNA and subsequent amplification by RT-PCR, to sequence the non-coding termini (NCRs). This necessitated the design of novel primers for an N8 neuraminidase segment. Results Two field isolates were sequenced successfully, A/Equine/Lincolnshire/1/07 and A/Equine/Richmond/1/07, representative of the Florida sublineage clades 1 and 2 respectively. A total of 26 PCR products varying in length from 400–600 nucleotides allowed full coverage of the coding sequences of the eight segments, with sufficient overlap to allow sequence assembly with no primer-derived sequences. Sequences were also determined for the non-coding regions and revealed cytosine at nucleotide 4 in the polymerase segments. Analysis of EIV genomes sequenced using these methods revealed a novel polymorphism in the PA-X protein in some isolates. Conclusions These methods can be used to determine the genome sequences of EIV, including the NCRs, from both clade 1 and clade 2 of the Florida sublineage. Full genomes were covered efficiently using fewer PCR products than previously reported methods for Influenza A viruses, the techniques used are affordable and the equipment required is available in most research laboratories. The adoption of these methods will hopefully allow for an increase in the number of full genomes available for EIV, leading to improved surveillance and a better understanding of EIV evolution.
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An efficient genome sequencing method for Equine Influenza [H3N8] virus reveals a new polymorphism in the PA-X protein
Virology journal, 2014Co-Authors: Adam Rash, Alana Woodward, Neil Bryant, John W. Mccauley, Debra EltonAbstract:H3N8 Equine Influenza virus (EIV) has caused disease outbreaks in horses across the world since its first isolation in 1963. However, unlike human, swine and avian Influenza, there is relatively little sequence data available for this virus. The majority of published sequences are for the segment encoding haemagglutinin (HA), one of the two surface glycoproteins, making it difficult to study the evolution of the other gene segments and determine the level of reassortment occurring between sub-lineages. To facilitate the generation of full genome sequences for EIV, we developed a simple, cost-effective and efficient method. M13-tagged primers were used to amplify short, overlapping RT-PCR products, which were then sequenced using Sanger dideoxynucleotide sequencing technology. We also modified a previously published method, developed for human H3N2 and avian H5N1 Influenza viruses, which was based on the ligation of viral RNA and subsequent amplification by RT-PCR, to sequence the non-coding termini (NCRs). This necessitated the design of novel primers for an N8 neuraminidase segment. Two field isolates were sequenced successfully, A/Equine/Lincolnshire/1/07 and A/Equine/Richmond/1/07, representative of the Florida sublineage clades 1 and 2 respectively. A total of 26 PCR products varying in length from 400–600 nucleotides allowed full coverage of the coding sequences of the eight segments, with sufficient overlap to allow sequence assembly with no primer-derived sequences. Sequences were also determined for the non-coding regions and revealed cytosine at nucleotide 4 in the polymerase segments. Analysis of EIV genomes sequenced using these methods revealed a novel polymorphism in the PA-X protein in some isolates. These methods can be used to determine the genome sequences of EIV, including the NCRs, from both clade 1 and clade 2 of the Florida sublineage. Full genomes were covered efficiently using fewer PCR products than previously reported methods for Influenza A viruses, the techniques used are affordable and the equipment required is available in most research laboratories. The adoption of these methods will hopefully allow for an increase in the number of full genomes available for EIV, leading to improved surveillance and a better understanding of EIV evolution.
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Protection, systemic IFN$\gamma$, and antibody responses induced by an ISCOM-based vaccine against a recent Equine Influenza virus in its natural host
Veterinary research, 2008Co-Authors: Romain Paillot, Debra Elton, Humphrey Grimmett, Janet M DalyAbstract:In the horse, conventional inactivated or subunit vaccines against Equine Influenza virus (EIV) induce a short-lived antibody-based immunity to infection. Alternative strategies of vaccination have been subsequently developed to mimic the long-term protection induced by natural infection with the virus. One of these approaches is the use of immune-stimulating complex (ISCOM)-based vaccines. ISCOM vaccines induce a strong antibody response and protection against Influenza in horses, humans, and a mouse model. Cell-mediated immunity (CMI) has been demonstrated in humans and mice after ISCOM vaccination, but rarely investigated in the horse. The aim of this study was to evaluate EIV-specific immune responses after intra-muscular vaccination with an ISCOM-EIV vaccine (EQUIP F) containing both Equine Influenza H7N7 (A/eq/Newmarket/77) and H3N8 (A/eq/Borlange/91 and A/eq/Kentucky/98) strains. The antibody response was measured by single radial haemolysis (SRH) assay using different H3N8 EIV strains. Stimulation of type-1 immunity was evaluated with a recently developed method that measures EIV-specific IFN synthesis by peripheral blood lymphocytes (PBL). The protective efficacy of this ISCOM-based vaccine against challenge infection with a recent Equine Influenza (H3N8; A/eq/South Africa/4/03) strain was also evaluated. Vaccinated ponies developed elevated levels of EIV-specific SRH antibody and increased percentage of EIV-specific IFN + PBL, whereas these responses were only detected after challenge infection in unvaccinated control ponies. Vaccinates showed minimal signs of disease and did not shed virus when challenged shortly after the second immunisation. In conclusion, evidence of type-1 immunity induced by an ISCOM-based vaccine is described for the first time in horses. Equine Influenza virus / vaccine / ISCOM / Equine IFN gamma / immunity
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Protection, systemic IFN$\gamma$, and antibody responses induced by an ISCOM-based vaccine against a recent Equine Influenza virus in its natural host
Veterinary Research, 2008Co-Authors: Romain Paillot, Debra Elton, Humphrey Grimmett, Janet DalyAbstract:In the horse, conventional inactivated or subunit vaccines against Equine Influenza virus (EIV) induce a short-lived antibody-based immunity to infection. Alternative strategies of vaccination have been subsequently developed to mimic the long-term protection induced by natural infection with the virus. One of these approaches is the use of immune-stimulating complex (ISCOM)-based vaccines. ISCOM vaccines induce a strong antibody response and protection against Influenza in horses, humans, and a mouse model. Cell-mediated immunity (CMI) has been demonstrated in humans and mice after ISCOM vaccination, but rarely investigated in the horse. The aim of this study was to evaluate EIV-specific immune responses after intra-muscular vaccination with an ISCOM-EIV vaccine (EQUIP F) containing both Equine Influenza H7N7 (A/eq/Newmarket/77) and H3N8 (A/eq/Borlänge/91 and A/eq/Kentucky/98) strains. The antibody response was measured by single radial haemolysis (SRH) assay using different H3N8 EIV strains. Stimulation of type-1 immunity was evaluated with a recently developed method that measures EIV-specific IFN$\gamma$ synthesis by peripheral blood lymphocytes (PBL). The protective efficacy of this ISCOM-based vaccine against challenge infection with a recent Equine Influenza (H3N8; A/eq/South Africa/4/03) strain was also evaluated. Vaccinated ponies developed elevated levels of EIV-specific SRH antibody and increased percentage of EIV-specific IFN$\gamma^+$ PBL, whereas these responses were only detected after challenge infection in unvaccinated control ponies. Vaccinates showed minimal signs of disease and did not shed virus when challenged shortly after the second immunisation. In conclusion, evidence of type-1 immunity induced by an ISCOM-based vaccine is described for the first time in horses.
Janet M Daly - One of the best experts on this subject based on the ideXlab platform.
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Protection, systemic IFN$\gamma$, and antibody responses induced by an ISCOM-based vaccine against a recent Equine Influenza virus in its natural host
Veterinary research, 2008Co-Authors: Romain Paillot, Debra Elton, Humphrey Grimmett, Janet M DalyAbstract:In the horse, conventional inactivated or subunit vaccines against Equine Influenza virus (EIV) induce a short-lived antibody-based immunity to infection. Alternative strategies of vaccination have been subsequently developed to mimic the long-term protection induced by natural infection with the virus. One of these approaches is the use of immune-stimulating complex (ISCOM)-based vaccines. ISCOM vaccines induce a strong antibody response and protection against Influenza in horses, humans, and a mouse model. Cell-mediated immunity (CMI) has been demonstrated in humans and mice after ISCOM vaccination, but rarely investigated in the horse. The aim of this study was to evaluate EIV-specific immune responses after intra-muscular vaccination with an ISCOM-EIV vaccine (EQUIP F) containing both Equine Influenza H7N7 (A/eq/Newmarket/77) and H3N8 (A/eq/Borlange/91 and A/eq/Kentucky/98) strains. The antibody response was measured by single radial haemolysis (SRH) assay using different H3N8 EIV strains. Stimulation of type-1 immunity was evaluated with a recently developed method that measures EIV-specific IFN synthesis by peripheral blood lymphocytes (PBL). The protective efficacy of this ISCOM-based vaccine against challenge infection with a recent Equine Influenza (H3N8; A/eq/South Africa/4/03) strain was also evaluated. Vaccinated ponies developed elevated levels of EIV-specific SRH antibody and increased percentage of EIV-specific IFN + PBL, whereas these responses were only detected after challenge infection in unvaccinated control ponies. Vaccinates showed minimal signs of disease and did not shed virus when challenged shortly after the second immunisation. In conclusion, evidence of type-1 immunity induced by an ISCOM-based vaccine is described for the first time in horses. Equine Influenza virus / vaccine / ISCOM / Equine IFN gamma / immunity
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An outbreak of Equine Influenza (H3N8) in Croatia in 2004 caused by South American lineage
2006Co-Authors: Ljubo Barbić, Janet M Daly, Nevenka Rudan, Snježana Kovač, Vladimir Savić, Slavko Cvetnić, Josip MadićAbstract:Several epizootics of Equine Influenza have been reported in Croatia in the past. Both subtypes, A/Equine-1 (H7N7) and A/Equine-2 (H3N8) were isolated. An outbreak of Equine Influenza in 2004, in racehorses on Zagreb hippodrome is described. Both unvaccinated and vaccinated horses showed clinical signs of respiratory disease. By cross HI test and serological examinations of paired sera of apparently affected horses, Equine Influenza (H3N8) virus was detected. Antigenic and genetic analysis of isolated viruses revealed the occurrence of South American sublineage of Equine-2 (H3N8) Influenza virus. The results presented in this work demonstrated that the HA1 gene sequence of the 6 isolates that were sequenced had only a single, non-coding nucleotide substitution among them. When the amino acid sequences of the Croatian isolates were aligned with a virus isolated in the UK during a widespread outbreak in the spring of 2003 (Newmarket/5/03), only a single amino acid substitution in the signal sequence was seen.
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description of the outbreak of Equine Influenza H3N8 in the united kingdom in 2003 during which recently vaccinated horses in newmarket developed respiratory disease
Veterinary Record, 2006Co-Authors: J R Newton, Janet M Daly, L Spencer, J A MumfordAbstract:Between March and May 2003, Equine Influenza virus infection was confirmed as the cause of clinical respiratory disease among both vaccinated and unvaccinated horses of different breeds and types in at least 12 locations in the UK. In the largest outbreak, 21 thoroughbred training yards in Newmarket, with more than 1300 racehorses, were affected, with the horses showing signs of coughing and nasal discharge during a period of nine weeks. Many of the infected horses had been vaccinated during the previous three months with a vaccine that contained representatives from both the European (A/eq/Newmarket/2/93) and American (A/eq/Newmarket/1/93) H3N8 Influenza virus lineages. Antigenic and genetic characterisation of the viruses from Newmarket and elsewhere indicated that they were all closely related to representatives of a sublineage of American viruses, for example, Kentucky/5/02, the first time that this sublineage had been isolated in the UK. In the recently vaccinated racehorses in Newmarket the single radial haemolysis antibody levels in acute sera appeared to be adequate, and there did not appear to be significant antigenic differences between the infecting virus and A/eq/Newmarket/1/93, the representative of the American lineage virus present in the most widely used vaccine, to explain the vaccine failure. However, there was evidence for significantly fewer infections among two-year-old horses than older animals, despite their having similar high levels of antibody, consistent with a qualitative rather than a quantitative difference in the immunity conveyed by the vaccination.
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Diagnostic methods applied to analysis of an outbreak of Equine Influenza in a riding school in which vaccine failure occurred
Veterinary Microbiology, 2003Co-Authors: Catharine Van Maanen, G.j Van Essen, Jules Maarten Minke, Janet M Daly, P. J. YatesAbstract:An outbreak of Equine Influenza H3N8 in a riding school is described retrospectively with emphasis on diagnosis and putative vaccine failure. In March 1995 an outbreak of Equine Influenza occurred among 11 horses in a riding school, where most horses had received basic primary immunizations and several booster vaccinations against Influenza. Six of the 11 diseased horses had received their last booster vaccination within 5 months of the outbreak. Nevertheless, the Influenza infection spread rapidly and clinical manifestations were prominent with frequent, harsh, dry coughing often accompanied by high fever. Nasal swabs were taken from 11 diseased horses. Influenza A virus of the Equine H3N8 (equi-2) subtype was isolated from five nasal swab extracts. Stored nasal swab extracts were also retrospectively investigated in two different enzyme immunoassays designed to detect the type-specific conserved nucleoprotein of Influenza A viruses, and in a single-tube reverse transcription-PCR (RT-PCR) using a set of primers based on highly conserved regions of the matrix gene of Influenza A viruses. Five nasal swab extracts were found positive in a DAS-ELISA and seven in the Directigen® Flu A (DFA) assay, respectively. Two nasal swab extracts from which virus was isolated did not give a positive result in the DAS-ELISA, and one of these also did not give a positive result in the DFA assay. Nine nasal swab extracts were found positive by RT-PCR. Moreover, all virus isolation and/or ELISA positive nasal swab extracts were confirmed by RT-PCR. Three nasal swab extracts were negative by virus isolation, PCR and ELISA. A significant rise in HI titre against Influenza A/eq/Miami/63 (H3N8) virus was detected in seven of the nine paired sera available. In acute phase serum samples from 10 horses, SRH antibody levels varied widely. However, some horses with high, or at least putatively clinically protective SRH antibody levels, showed clinical signs and infection was confirmed. Antigenic analysis of two isolates showed that A/eq/Holland/1/95 (H3N8) and A/eq/Holland/2/95 (H3N8) cluster with the UK isolate Osgodsby/92, the Swedish isolate Borlange/91 and some other European isolates, with H/2/95 identical in reactivity to Borlange/91 and H/1/95 more similar in reactivity to Osgodsby/92 than H/2/95. Nucleotide and deduced amino-acid sequences showed large differences of both isolates as compared with Miami/63, Fontainebleau/79 and Kentucky/81, the Influenza A H3N8 subtype strains incorporated in the vaccines used in this riding school. The role of antigenic drift in vaccine breakdown is discussed in the light of evidence for vaccine breakdown in the UK in 1989, Sweden in 1991 and in the USA since 1991.
J A Mumford - One of the best experts on this subject based on the ideXlab platform.
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description of the outbreak of Equine Influenza H3N8 in the united kingdom in 2003 during which recently vaccinated horses in newmarket developed respiratory disease
Veterinary Record, 2006Co-Authors: J R Newton, Janet M Daly, L Spencer, J A MumfordAbstract:Between March and May 2003, Equine Influenza virus infection was confirmed as the cause of clinical respiratory disease among both vaccinated and unvaccinated horses of different breeds and types in at least 12 locations in the UK. In the largest outbreak, 21 thoroughbred training yards in Newmarket, with more than 1300 racehorses, were affected, with the horses showing signs of coughing and nasal discharge during a period of nine weeks. Many of the infected horses had been vaccinated during the previous three months with a vaccine that contained representatives from both the European (A/eq/Newmarket/2/93) and American (A/eq/Newmarket/1/93) H3N8 Influenza virus lineages. Antigenic and genetic characterisation of the viruses from Newmarket and elsewhere indicated that they were all closely related to representatives of a sublineage of American viruses, for example, Kentucky/5/02, the first time that this sublineage had been isolated in the UK. In the recently vaccinated racehorses in Newmarket the single radial haemolysis antibody levels in acute sera appeared to be adequate, and there did not appear to be significant antigenic differences between the infecting virus and A/eq/Newmarket/1/93, the representative of the American lineage virus present in the most widely used vaccine, to explain the vaccine failure. However, there was evidence for significantly fewer infections among two-year-old horses than older animals, despite their having similar high levels of antibody, consistent with a qualitative rather than a quantitative difference in the immunity conveyed by the vaccination.
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Equine Influenza vaccine efficacy: the significance of antigenic variation.
Veterinary microbiology, 2000Co-Authors: P Yates, J A MumfordAbstract:To investigate the level of cross-protection induced by Equine Influenza H3N8 vaccines derived from different lineages, two studies have been carried out with ponies vaccinated with 'American-like' and 'European-like' vaccines and experimentally challenged with a European-like strain. The results demonstrated that Equine Influenza vaccines clearly protect against challenge with homologous virus if serum antibody titres are sufficiently high. On the other hand, protection is incomplete even when animals vaccinated with heterologous strains have comparative antibody levels. Nevertheless, the protection afforded by heterologous viruses can be improved by stimulating high levels of antibody. It would be advisable to update Equine Influenza vaccine strains regularly so that they contain similar strains to variants that are circulating in the field.
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Antigenic and genetic evolution of Equine H3N8 Influenza A viruses.
The Journal of general virology, 1996Co-Authors: J M Daly, A C Lai, M M Binns, T M Chambers, M Barrandeguy, J A MumfordAbstract:Evolution of Equine Influenza a H3N8 viruses was examined by antigenic and genetic analysis of a collection isolates from around the world. It was noted that antigenic and genetic variants of Equine H3N8 viruses cocirculate, and in particular that variants currently circulating in Europe and the USA are distinguishable from one another both in terms of antigenic reactivity and genetic structure of the HA1 portion of the haemagglutinin (HA) molecule. Whilst the divergent evolution of American and European isolates may be due to geographical isolation of the two gene pools, some mixing is believed to occur as 'American-like' viruses have been isolated during outbreaks of Equine Influenza in the UK. The cocirculation of two antigenically and genetically distinct lineages of Equine Influenza H3N8 viruses has serious implications for vaccine strain selection.
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The outbreak of Equine Influenza (H3N8) in the United Kingdom in 1989: diagnostic use of an antigen capture ELISA.
The Veterinary record, 1993Co-Authors: Georgia J. Livesay, Duncan Hannant, T. O'neill, Mp Yadav, J A MumfordAbstract:In July 1989 Influenza A/Equine-2 (H3N8) was isolated from a nasopharyngeal swab taken from a non-thoroughbred horse exhibiting acute clinical respiratory disease. This was the first isolation of Equine Influenza virus in the United Kingdom since 1981. Subsequent investigations of acute respiratory disease in horses indicated that the infection was dispersed throughout the UK. However, unlike the previous epidemic of 1979, the first horses from which the virus was isolated had been vaccinated. This outbreak of Influenza provided an opportunity to evaluate an antigen capture ELISA, directed against the Influenza virus nucleoprotein, as a rapid method for detecting virus in the nasopharyngeal secretions of naturally infected horses.
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Genetic and antigenic analysis of an Equine Influenza H 3 isolate from the 1989 epidemic
Archives of Virology, 1993Co-Authors: M M Binns, J A Mumford, J M Daly, E. D. Chirnside, J. M. Wood, C. M. Richards, R. S. DanielsAbstract:The haemagglutinin (HA) gene from the Equine Influenza H3N8 isolate Suffolk/89 has been cloned by reverse transcription and polymerase chain reaction amplification. The nucleotide sequence of the HA gene was determined from two independently cloned copies of the gene and was found to be most closely related to recent American isolates supporting the idea that most isolates of Equine H3N8 are evolving as a single lineage. When the predicted amino acid sequence of the Suffolk/89 HA was examined, changes had taken place in at least four of the major antigenic sites, A, B, C, and D when compared to the sequences of the isolates used in the current vaccines (Miami/63 and Fontainebleau/79). Surprisingly, when the Suffolk/89 isolate was tested in haemagglutination inhibition (HI) assays with a panel of six mouse monoclonal antibodies, no differences were observed between the Suffolk/89 and the Fontainebleau/79 isolates, suggesting that this panel of monoclonal antibodies may recognise a limited subset of the major antigenic sites. Three anti-HA horse heterohybridoma monoclonals were able to distinguish between the Suffolk/89 and Fontainebleau/79 viruses, demonstrating that the horse does recognise these isolates as being antigenically different. The results of the work suggest that the isolates used in current Equine Influenza vaccines may need updating.
Romain Paillot - One of the best experts on this subject based on the ideXlab platform.
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Protection, systemic IFN$\gamma$, and antibody responses induced by an ISCOM-based vaccine against a recent Equine Influenza virus in its natural host
Veterinary research, 2008Co-Authors: Romain Paillot, Debra Elton, Humphrey Grimmett, Janet M DalyAbstract:In the horse, conventional inactivated or subunit vaccines against Equine Influenza virus (EIV) induce a short-lived antibody-based immunity to infection. Alternative strategies of vaccination have been subsequently developed to mimic the long-term protection induced by natural infection with the virus. One of these approaches is the use of immune-stimulating complex (ISCOM)-based vaccines. ISCOM vaccines induce a strong antibody response and protection against Influenza in horses, humans, and a mouse model. Cell-mediated immunity (CMI) has been demonstrated in humans and mice after ISCOM vaccination, but rarely investigated in the horse. The aim of this study was to evaluate EIV-specific immune responses after intra-muscular vaccination with an ISCOM-EIV vaccine (EQUIP F) containing both Equine Influenza H7N7 (A/eq/Newmarket/77) and H3N8 (A/eq/Borlange/91 and A/eq/Kentucky/98) strains. The antibody response was measured by single radial haemolysis (SRH) assay using different H3N8 EIV strains. Stimulation of type-1 immunity was evaluated with a recently developed method that measures EIV-specific IFN synthesis by peripheral blood lymphocytes (PBL). The protective efficacy of this ISCOM-based vaccine against challenge infection with a recent Equine Influenza (H3N8; A/eq/South Africa/4/03) strain was also evaluated. Vaccinated ponies developed elevated levels of EIV-specific SRH antibody and increased percentage of EIV-specific IFN + PBL, whereas these responses were only detected after challenge infection in unvaccinated control ponies. Vaccinates showed minimal signs of disease and did not shed virus when challenged shortly after the second immunisation. In conclusion, evidence of type-1 immunity induced by an ISCOM-based vaccine is described for the first time in horses. Equine Influenza virus / vaccine / ISCOM / Equine IFN gamma / immunity
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Protection, systemic IFN$\gamma$, and antibody responses induced by an ISCOM-based vaccine against a recent Equine Influenza virus in its natural host
Veterinary Research, 2008Co-Authors: Romain Paillot, Debra Elton, Humphrey Grimmett, Janet DalyAbstract:In the horse, conventional inactivated or subunit vaccines against Equine Influenza virus (EIV) induce a short-lived antibody-based immunity to infection. Alternative strategies of vaccination have been subsequently developed to mimic the long-term protection induced by natural infection with the virus. One of these approaches is the use of immune-stimulating complex (ISCOM)-based vaccines. ISCOM vaccines induce a strong antibody response and protection against Influenza in horses, humans, and a mouse model. Cell-mediated immunity (CMI) has been demonstrated in humans and mice after ISCOM vaccination, but rarely investigated in the horse. The aim of this study was to evaluate EIV-specific immune responses after intra-muscular vaccination with an ISCOM-EIV vaccine (EQUIP F) containing both Equine Influenza H7N7 (A/eq/Newmarket/77) and H3N8 (A/eq/Borlänge/91 and A/eq/Kentucky/98) strains. The antibody response was measured by single radial haemolysis (SRH) assay using different H3N8 EIV strains. Stimulation of type-1 immunity was evaluated with a recently developed method that measures EIV-specific IFN$\gamma$ synthesis by peripheral blood lymphocytes (PBL). The protective efficacy of this ISCOM-based vaccine against challenge infection with a recent Equine Influenza (H3N8; A/eq/South Africa/4/03) strain was also evaluated. Vaccinated ponies developed elevated levels of EIV-specific SRH antibody and increased percentage of EIV-specific IFN$\gamma^+$ PBL, whereas these responses were only detected after challenge infection in unvaccinated control ponies. Vaccinates showed minimal signs of disease and did not shed virus when challenged shortly after the second immunisation. In conclusion, evidence of type-1 immunity induced by an ISCOM-based vaccine is described for the first time in horses.
Janet Daly - One of the best experts on this subject based on the ideXlab platform.
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Protection, systemic IFN$\gamma$, and antibody responses induced by an ISCOM-based vaccine against a recent Equine Influenza virus in its natural host
Veterinary Research, 2008Co-Authors: Romain Paillot, Debra Elton, Humphrey Grimmett, Janet DalyAbstract:In the horse, conventional inactivated or subunit vaccines against Equine Influenza virus (EIV) induce a short-lived antibody-based immunity to infection. Alternative strategies of vaccination have been subsequently developed to mimic the long-term protection induced by natural infection with the virus. One of these approaches is the use of immune-stimulating complex (ISCOM)-based vaccines. ISCOM vaccines induce a strong antibody response and protection against Influenza in horses, humans, and a mouse model. Cell-mediated immunity (CMI) has been demonstrated in humans and mice after ISCOM vaccination, but rarely investigated in the horse. The aim of this study was to evaluate EIV-specific immune responses after intra-muscular vaccination with an ISCOM-EIV vaccine (EQUIP F) containing both Equine Influenza H7N7 (A/eq/Newmarket/77) and H3N8 (A/eq/Borlänge/91 and A/eq/Kentucky/98) strains. The antibody response was measured by single radial haemolysis (SRH) assay using different H3N8 EIV strains. Stimulation of type-1 immunity was evaluated with a recently developed method that measures EIV-specific IFN$\gamma$ synthesis by peripheral blood lymphocytes (PBL). The protective efficacy of this ISCOM-based vaccine against challenge infection with a recent Equine Influenza (H3N8; A/eq/South Africa/4/03) strain was also evaluated. Vaccinated ponies developed elevated levels of EIV-specific SRH antibody and increased percentage of EIV-specific IFN$\gamma^+$ PBL, whereas these responses were only detected after challenge infection in unvaccinated control ponies. Vaccinates showed minimal signs of disease and did not shed virus when challenged shortly after the second immunisation. In conclusion, evidence of type-1 immunity induced by an ISCOM-based vaccine is described for the first time in horses.