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Crew CR, Brennan ML, Ireland JL. Implementation of biosecurity on equestrian premises: A narrative overview. Vet J 2023; 292:105950. [PMID: 36642241 DOI: 10.1016/j.tvjl.2023.105950] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 01/05/2023] [Accepted: 01/11/2023] [Indexed: 01/15/2023]
Abstract
Biosecurity measures are designed to prevent the introduction and spread of pathogens, and play a vital role in the equine industry, controlling endemic diseases and reducing the threat of exotic disease incursion. Equestrian premises differ with respect to disease risks, biosecurity requirements and available facilities. This narrative review summarises reported frequency of implementation for selected biosecurity measures, as well as evidence relating to potential barriers to implementation of biosecurity on equestrian premises. Possible opportunities for improvement in the adoption of equine biosecurity measures are also discussed.
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Affiliation(s)
- C R Crew
- Department of Health and Social Care, 39 Victoria Street, London SW1H 0EU, UK; The Royal Veterinary College, Hawkshead Lane, Hatfield, Hertfordshire AL9 7TA, UK
| | - M L Brennan
- School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington Campus, Leicestershire LE12 5RD, UK
| | - J L Ireland
- Institute of Infection, Veterinary and Ecological Sciences, Faculty of Health and Life Sciences, The University of Liverpool, Leahurst Campus, Neston, Cheshire CH64 7TE, UK.
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Colgate VA, Newton JR. Equine influenza bi-annual boosters: What does the evidence tell us? Equine Vet J 2023; 55:147-152. [PMID: 36382414 DOI: 10.1111/evj.13898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Accepted: 10/28/2022] [Indexed: 11/18/2022]
Affiliation(s)
- Victoria A Colgate
- Equine Infectious Disease Surveillance, Department of Veterinary Medicine, University of Cambridge, Cambridge, UK
| | - J Richard Newton
- Equine Infectious Disease Surveillance, Department of Veterinary Medicine, University of Cambridge, Cambridge, UK
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El-Hage C, Hartley C, Savage C, Watson J, Gilkerson J, Paillot R. Assessment of Humoral and Long-Term Cell-Mediated Immune Responses to Recombinant Canarypox-Vectored Equine Influenza Virus Vaccination in Horses Using Conventional and Accelerated Regimens Respectively. Vaccines (Basel) 2022; 10:vaccines10060855. [PMID: 35746463 PMCID: PMC9229645 DOI: 10.3390/vaccines10060855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 05/19/2022] [Accepted: 05/25/2022] [Indexed: 02/05/2023] Open
Abstract
During Australia's first and only outbreak of equine influenza (EI), which was restricted to two northeastern states, horses were strategically vaccinated with a recombinant canarypox-vectored vaccine (rCP-EIV; ProteqFlu™, Merial P/L). The vaccine encoded for haemagglutinin (HA) belonging to two equine influenza viruses (EIVs), including an American and Eurasian lineage subtype that predated the EIV responsible for the outbreak (A/equine/Sydney/07). Racehorses in Victoria (a southern state that remained free of EI) were vaccinated prophylactically. Although the vaccine encoded for (HA) belonged to two EIVs of distinct strains of the field virus, clinical protection was reported in vaccinated horses. Our aim is to assess the extent of humoral immunity in one group of vaccinated horses and interferon-gamma ((EIV)-IFN-γ)) production in the peripheral blood mononuclear cells (PBMCs) of a second population of vaccinated horses. Twelve racehorses at work were monitored for haemagglutination inhibition antibodies to three antigenically distinct equine influenza viruses (EIVs) The EIV antigens included two H3N8 subtypes: A/equine/Sydney/07) A/equine/Newmarket/95 (a European lineage strain) and an H7N7 subtype (A/equine/Prague1956). Cell-mediated immune responses of: seven racehorses following an accelerated vaccination schedule, two horses vaccinated using a conventional regimen, and six unvaccinated horses were evaluated by determining (EIV)-IFN-γ levels. Antibody responses following vaccination with ProteqFlu™ were cross-reactive in nature, with responses to both H3N8 EIV strains. Although (EIV)IFN-γ was clearly detected following the in vitro re-stimulation of PBMC, there was no significant difference between the different groups of horses. Results of this study support reports of clinical protection of Australian horses following vaccination with Proteq-Flu™ with objective evidence of humoral cross-reactivity to the outbreak viral strain A/equine/Sydney/07.
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Affiliation(s)
- Charles El-Hage
- Centre for Equine Infectious Diseases, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC 3010, Australia; (C.H.); (C.S.); (J.G.)
- Correspondence: ; Tel.: +61-417166029
| | - Carol Hartley
- Centre for Equine Infectious Diseases, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC 3010, Australia; (C.H.); (C.S.); (J.G.)
| | - Catherine Savage
- Centre for Equine Infectious Diseases, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC 3010, Australia; (C.H.); (C.S.); (J.G.)
| | - James Watson
- Australian Centre for Disease Preparedness, CSIRO, Geelong, VIC 3216, Australia;
| | - James Gilkerson
- Centre for Equine Infectious Diseases, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC 3010, Australia; (C.H.); (C.S.); (J.G.)
| | - Romain Paillot
- School of Equine and Veterinary Physiotherapy, Writtle University College, Lordship Road, Writtle, Chelmsford CM1 3RR, UK;
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Equine Influenza Virus and Vaccines. Viruses 2021; 13:v13081657. [PMID: 34452521 PMCID: PMC8402878 DOI: 10.3390/v13081657] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 07/27/2021] [Accepted: 07/28/2021] [Indexed: 01/01/2023] Open
Abstract
Equine influenza virus (EIV) is a constantly evolving viral pathogen that is responsible for yearly outbreaks of respiratory disease in horses termed equine influenza (EI). There is currently no evidence of circulation of the original H7N7 strain of EIV worldwide; however, the EIV H3N8 strain, which was first isolated in the early 1960s, remains a major threat to most of the world's horse populations. It can also infect dogs. The ability of EIV to constantly accumulate mutations in its antibody-binding sites enables it to evade host protective immunity, making it a successful viral pathogen. Clinical and virological protection against EIV is achieved by stimulation of strong cellular and humoral immunity in vaccinated horses. However, despite EI vaccine updates over the years, EIV remains relevant, because the protective effects of vaccines decay and permit subclinical infections that facilitate transmission into susceptible populations. In this review, we describe how the evolution of EIV drives repeated EI outbreaks even in horse populations with supposedly high vaccination coverage. Next, we discuss the approaches employed to develop efficacious EI vaccines for commercial use and the existing system for recommendations on updating vaccines based on available clinical and virological data to improve protective immunity in vaccinated horse populations. Understanding how EIV biology can be better harnessed to improve EI vaccines is central to controlling EI.
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Abstract
Influenza is an extremely contagious respiratory disease, which predominantly affects the upper respiratory tract. There are four types of influenza virus, and pigs and chickens are considered two key reservoirs of this virus. Equine influenza (EI) virus was first identified in horses in 1956, in Prague. The influenza A viruses responsible for EI are H7N7 and H3N8. Outbreaks of EI are characterized by their visible and rapid spread, and it has been possible to isolate and characterize H3N8 outbreaks in several countries. The clinical diagnosis of this disease is based on the clinical signs presented by the infected animals, which can be confirmed by performing complementary diagnostic tests. In the diagnosis of EI, in the field, rapid antigen detection tests can be used for a first approach. Treatment is based on the management of the disease and rest for the animal. Regarding the prognosis, it will depend on several factors, such as the animal's vaccination status. One of the important points in this disease is its prevention, which can be done through vaccination. In addition to decreasing the severity of clinical signs and morbidity during outbreaks, vaccination ensures immunity for the animals, reducing the economic impact of this disease.
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An Evaluation of Three Different Primary Equine Influenza Vaccination Intervals in Foals. J Equine Vet Sci 2021; 99:103397. [PMID: 33781435 DOI: 10.1016/j.jevs.2021.103397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2020] [Revised: 01/25/2021] [Accepted: 01/25/2021] [Indexed: 11/20/2022]
Abstract
In order to evaluate the effect of three different primary vaccination intervals on EI vaccine response, 21 unvaccinated thoroughbred foals were randomly divided into three groups of 7 and vaccinated with three different intervals of primary immunization (i.e., with 1, 2 or 3 months intervals between V1 and V2, respectively). The antibody response was measured for up to 1 year after the third immunization V3 (administered 6 months after V2) by single radial hemolysis (SRH) assay. All weanlings had seroconverted and exceeded the clinical protection threshold 2 weeks after V2 and 1 month after V3 until the end of the study. Significant differences were measured at the peak of immunity after V2 and for the duration of the immunity gap between V2 and V3. The group with one month primary vaccination interval had a lower immunity peak after V2 (158.05 ± 6.63 mm2) and a wider immunity gap between V2 and V3 (18 weeks) when compared with other groups (i.e., 174.72 ± 6.86 mm2 and 16 weeks for a two months interval, 221.45 ± 14.48 mm2 and 12 weeks for a 3-month interval). The advantage observed in the group with 1 month primary vaccination interval, which induces an earlier protective immunity, is counterbalance with a lower peak of immunity and a wider immunity gap after V2, when compared with foals vaccinated with 2- and 3-month intervals.
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Allkofer A, Garvey M, Ryan E, Lyons R, Ryan M, Lukaseviciute G, Walsh C, Venner M, Cullinane A. Primary vaccination in foals: a comparison of the serological response to equine influenza and equine herpesvirus vaccines administered concurrently or 2 weeks apart. Arch Virol 2021; 166:571-579. [PMID: 33410993 DOI: 10.1007/s00705-020-04846-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 09/09/2020] [Indexed: 10/22/2022]
Abstract
This study compared concurrent and separate primary vaccination against equid alphaherpesviruses 1 and 4, genus Varicellovirus, subfamily Alphaherpesvirinae, family Herpesviridae, and equine influenza A virus, genus Alphainfluenzavirus, family Orthomyxoviridae. Their vernacular names are equine herpesvirus 1 and 4 (EHV1/4) and equine influenza virus (EIV). Infection with these respiratory pathogens is associated with loss of performance, interruption of training schedules, and on occasion, cancellation of equestrian events. Vaccination is highly recommended, and for some activities it is a mandatory requirement of the relevant authority. As there is a dearth of information relating to the impact of concurrent vaccination on the antibody response to EHV and EIV vaccines, they are usually administered separately, often 2 weeks apart. In a previous study of booster vaccination in Thoroughbred racehorses, concurrent vaccination with whole-virus inactivated carbopol-adjuvanted EHV and EIV vaccines did not impact negatively on the antibody response. In this study, investigations were extended to concurrent versus separate primary vaccination of warmblood foals. A field study was conducted to compare the immune response to a carbopol-adjuvanted EHV vaccine and an immune stimulating complex (ISCOM)-adjuvanted EI vaccine administered concurrently and 2 weeks apart. No adverse clinical reactions were observed, the pattern of EI and EHV antibody response was similar for both groups, and there was no evidence that concurrent primary vaccination compromised the humoral response. The results are of relevance to horse owners who wish to decrease veterinary costs, limit handling of young animals, and simplify record keeping by vaccinating concurrently.
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Affiliation(s)
- Alexandra Allkofer
- Clinic for Horses, University of Veterinary Medicine Hanover, Hanover, Germany
| | - Marie Garvey
- Virology Unit, The Irish Equine Centre, Johnstown, Naas, Co. Kildare, W91 RH93, Ireland
| | - Evelyn Ryan
- Virology Unit, The Irish Equine Centre, Johnstown, Naas, Co. Kildare, W91 RH93, Ireland
| | - Rachel Lyons
- Virology Unit, The Irish Equine Centre, Johnstown, Naas, Co. Kildare, W91 RH93, Ireland
| | - Megan Ryan
- Virology Unit, The Irish Equine Centre, Johnstown, Naas, Co. Kildare, W91 RH93, Ireland
| | - Gabija Lukaseviciute
- Virology Unit, The Irish Equine Centre, Johnstown, Naas, Co. Kildare, W91 RH93, Ireland
| | - Cathal Walsh
- Department of Mathematics and Statistics, University of Limerick, Limerick, Ireland
| | - Monica Venner
- Equine Clinic Destedt, Trift 4, 38162, Destedt, Germany.
| | - Ann Cullinane
- Virology Unit, The Irish Equine Centre, Johnstown, Naas, Co. Kildare, W91 RH93, Ireland.
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Wilson A, Pinchbeck G, Dean R, McGowan C. Equine influenza vaccination in the UK: Current practices may leave horses with suboptimal immunity. Equine Vet J 2020; 53:1004-1014. [PMID: 33124070 PMCID: PMC8451788 DOI: 10.1111/evj.13377] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 09/26/2020] [Accepted: 10/22/2020] [Indexed: 11/30/2022]
Abstract
BACKGROUND Vaccination is integral to preventive healthcare. Despite numerous guidelines on equine vaccination, evidence of current vaccination practices is lacking. OBJECTIVES To describe current vaccination practices advised by vets treating horses in the United Kingdom (UK) and compare practices with manufacturer datasheets and current guidelines. STUDY DESIGN Cross-sectional survey. METHODS An online questionnaire was distributed using email addresses acquired through professional registration listings and social media, targeting vets who treat horses in the UK. The questionnaire collected demographic data and information regarding vaccination practices and vaccine hesitancy. Descriptive statistical analysis was performed. RESULTS Questionnaires were completed by 304 UK vets working with horses used for leisure (97.4%, n = 296/304), competition (86.2%, n = 262/304), stud-work (47.7%, n = 145/304) and racing (40.5%, n = 123/304). Variation was identified in vaccine protocols for competition and noncompetition horses. Fifty-seven per cent (n = 170/298) of respondents reported variation in advised 'booster' frequency; most commonly (n = 118) advising a 6-monthly vaccination in competition horses and annual vaccination in noncompetition horses. Most common vaccination guidelines volunteered were British Horseracing Authority (68.8%, n = 172/250) and Federation Equestre Internationale (66.4%, n = 166/250). Most vaccination practices were not consistent with datasheet guidance. Only 7.7% (n = 23/300) of respondents complied with datasheet timeframes between the second and third vaccination. Adverse events following vaccination in the previous year were encountered by 66% (n = 199/304) of respondents, representing 2760 adverse events; but only 526 (19.1%) cases were reported to the Veterinary Medicines Directorate. Most common reactions were transient, including stiffness (931), localised swelling (835), lethargy (559) and pyrexia (355). 86.4% respondents reported vaccine hesitancy from horse owners, most commonly due to perception of over-vaccination, cost and concern regarding adverse events. MAIN LIMITATIONS Potential selection, respondent and recall bias. The recent Equine Influenza (EI) and Equine Herpes Virus (EHV) outbreaks in the UK may have altered responses. CONCLUSIONS Current equine vaccination practices, although complying with competition rules, are mostly noncompliant with datasheet guidelines, potentially risking suboptimal immunity.
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Affiliation(s)
- Amie Wilson
- Department of Equine Clinical Science, Institute of Veterinary and Ecological Sciences, University of Liverpool, Neston, Cheshire, UK
| | - Gina Pinchbeck
- Department of Equine Clinical Science, Institute of Veterinary and Ecological Sciences, University of Liverpool, Neston, Cheshire, UK
| | | | - Catherine McGowan
- Department of Equine Clinical Science, Institute of Veterinary and Ecological Sciences, University of Liverpool, Neston, Cheshire, UK
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Determining Equine Influenza Virus Vaccine Efficacy-The Specific Contribution of Strain Versus Other Vaccine Attributes. Vaccines (Basel) 2020; 8:vaccines8030501. [PMID: 32899189 PMCID: PMC7564743 DOI: 10.3390/vaccines8030501] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 08/21/2020] [Accepted: 08/26/2020] [Indexed: 02/02/2023] Open
Abstract
Vaccination is an effective tool to limit equine influenza virus (EIV H3N8) infection, a contagious respiratory disease with potentially huge economic impact. The study assessed the effects of antigenic change on vaccine efficacy and the need for strain update. Horses were vaccinated (V1 and V2) with an ISCOMatrix-adjuvanted, whole inactivated virus vaccine (Equilis Prequenza, group 2, FC1 and European strains) or a carbomer-adjuvanted, modified vector vaccine (ProteqFlu, group 3, FC1 and FC2 HA genes). Serology (SRH, HI, VN), clinical signs and viral shedding were assessed in comparison to unvaccinated control horses. The hypothesis was that group 2 (no FC2 vaccine strain) would be less well protected than group 3 following experimental infection with a recent FC2 field strain (A/equi-2/Wexford/14) 4.5 months after vaccination. All vaccinated horses had antibody titres to FC1 and FC2. After challenge, serology increased more markedly in group 3 than in group 2. Vaccinated horses had significantly lower total clinical scores and viral shedding. Unexpectedly, viral RNA shedding was significantly lower in group 2 than in group 3. Vaccination induced protective antibody titres to FC1 and FC2 and reduced clinical signs and viral shedding. The two tested vaccines provided equivalent protection against a recent FC2 EIV field strain.
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Kinsley R, Pronost S, De Bock M, Temperton N, Daly JM, Paillot R, Scott S. Evaluation of a Pseudotyped Virus Neutralisation Test for the Measurement of Equine Influenza Virus-Neutralising Antibody Responses Induced by Vaccination and Infection. Vaccines (Basel) 2020; 8:vaccines8030466. [PMID: 32825702 PMCID: PMC7565038 DOI: 10.3390/vaccines8030466] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2020] [Revised: 08/05/2020] [Accepted: 08/15/2020] [Indexed: 01/03/2023] Open
Abstract
Equine influenza is a major respiratory disease of horses that is largely controlled by vaccination in some equine populations. Virus-neutralising antibodies, the mainstay of the protective immune response, are problematic in assaying for equine influenza virus, as most strains do not replicate efficiently in cell culture. Surrogate measures of protective antibody responses include the haemagglutination inhibition (HI) test and single radial haemolysis (SRH) assay. For this study, a pseudotyped virus, bearing an envelope containing the haemagglutinin (HA) from the Florida clade 2 equine influenza virus strain A/equine/Richmond/1/07 (H3N8), was generated to measure HA-specific neutralising antibodies in serum samples (n = 134) from vaccinated or experimentally-infected ponies using a pseudotyped virus neutralization test (PVNT). Overall, the results of PVNT were in good agreement with results from the SRH assay (100% sensitivity, 68.53% specificity) and HI test (99.2% sensitivity, 49.03% specificity). The PVNT was apparently more sensitive than either the SRH assay or the HI test, which could be advantageous for studying the antibody kinetics, particularly when antibody levels are low. Nevertheless, further studies are required to determine whether a protective antibody level can be defined for the SRH assay and to ascertain the inter-laboratory reproducibility. In conclusion, the PVNT efficiently measures neutralising antibodies after immunization and/or experimental infection in the natural host, and may complement existing antibody assays.
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Affiliation(s)
- Rebecca Kinsley
- Viral Pseudotype Unit (VPU), Medway School of Pharmacy, Universities of Kent & Greenwich, Chatham Maritime ME4 4TB, UK; (R.K.); (N.T.)
| | - Stéphane Pronost
- LABÉO Frank Duncombe, 1 route de Rosel, 14053 Caen CEDEX 4, France;
- Normandie University, UNICAEN, BIOTARGEN EA7450, 14280 Saint-Contest, France
| | - Manuelle De Bock
- Elanco Animal Health, Plantin en Moretuslei, B-2018 Antwerpen, Belgium;
| | - Nigel Temperton
- Viral Pseudotype Unit (VPU), Medway School of Pharmacy, Universities of Kent & Greenwich, Chatham Maritime ME4 4TB, UK; (R.K.); (N.T.)
| | - Janet M. Daly
- School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington LE12 5RD, UK;
| | - Romain Paillot
- LABÉO Frank Duncombe, 1 route de Rosel, 14053 Caen CEDEX 4, France;
- Normandie University, UNICAEN, BIOTARGEN EA7450, 14280 Saint-Contest, France
- Animal Health Trust, Centre for Preventive Medicine, Lanwades Park, Kentford Newmarket CB8 7UU, UK
- Correspondence: (R.P.); (S.S.); Tel.: +33-231-471-926 (R.P.); +44-1634-202957 (S.S.)
| | - Simon Scott
- Viral Pseudotype Unit (VPU), Medway School of Pharmacy, Universities of Kent & Greenwich, Chatham Maritime ME4 4TB, UK; (R.K.); (N.T.)
- Correspondence: (R.P.); (S.S.); Tel.: +33-231-471-926 (R.P.); +44-1634-202957 (S.S.)
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Gildea S, Lyons P, Lyons R, Gahan J, Garvey M, Cullinane A. Annual booster vaccination and the risk of equine influenza to Thoroughbred racehorses. Equine Vet J 2020; 52:509-515. [PMID: 31750956 DOI: 10.1111/evj.13210] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 10/02/2019] [Accepted: 10/31/2019] [Indexed: 11/30/2022]
Abstract
BACKGROUND Equine influenza (EI) outbreaks occurred among horses on four racing yards (two National Hunt, one Flat, one mixed National Hunt racing/breeding yard) in Ireland within a 4-week period. OBJECTIVES To carry out a detailed analysis of racing yards affected in order to identify the source of infection and monitor virus spread among a vaccinated population. STUDY DESIGN Observational field study. METHODS Epidemiological and vaccination data along with repeat clinical samples were collected from 118 horses on four premises. RESULTS Failure to implement appropriate biosecurity measures following the introduction of new arrivals and the return of horses from equestrian events contributed to disease spread as did the movement of horses within premises. Mixing of racing and non-racing populations with inadequate vaccination histories also facilitated virus transmission. The index case(s) on all premises was vaccinated in accordance with the Turf Club rules. Vaccine breakdown was observed across all products in 27/80 horses (33.8%) with an up-to-date vaccination record. Eighteen of the 27 (66.7%) horses had not received a booster vaccination within the previous 6 months and 10 (37%) horses were due annual booster vaccination at the time of developing clinical signs. MAIN LIMITATIONS The interpretation of laboratory results followed a delay in veterinary intervention. CONCLUSIONS Annual booster vaccination should not be relied on as the sole preventative measure against EI. The findings of this study suggest that increasing the frequency of booster vaccinations may be beneficial particularly in young horses and that synchronised scheduling of vaccination regimes across racing yards may contribute to high-risk periods for EI virus (EIV) transmission.
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Affiliation(s)
- Sarah Gildea
- Virology Unit, The Irish Equine Centre, Johnstown, Naas, Kildare, Ireland
| | - Pamela Lyons
- Virology Unit, The Irish Equine Centre, Johnstown, Naas, Kildare, Ireland
| | - Rachel Lyons
- Virology Unit, The Irish Equine Centre, Johnstown, Naas, Kildare, Ireland
| | - Jacinta Gahan
- Virology Unit, The Irish Equine Centre, Johnstown, Naas, Kildare, Ireland
| | - Marie Garvey
- Virology Unit, The Irish Equine Centre, Johnstown, Naas, Kildare, Ireland
| | - Ann Cullinane
- Virology Unit, The Irish Equine Centre, Johnstown, Naas, Kildare, Ireland
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Daly JM, Murcia PR. Strategic implementation of vaccines for control of equine influenza. Equine Vet J 2018; 50:153-154. [PMID: 29392805 DOI: 10.1111/evj.12794] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- J M Daly
- School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington, Leicestershire, UK
| | - P R Murcia
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary Life Science, University of Glasgow, Centre for Virus Research, Glasgow, UK
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The Immunity Gap Challenge: Protection against a Recent Florida Clade 2 Equine Influenza Strain. Vaccines (Basel) 2018; 6:vaccines6030038. [PMID: 30004410 PMCID: PMC6161116 DOI: 10.3390/vaccines6030038] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Revised: 06/27/2018] [Accepted: 06/28/2018] [Indexed: 12/02/2022] Open
Abstract
Vaccination is one of the most effective tools for limiting the impact of equine influenza (EI). The humoral immunity established following a primary vaccination course can decrease significantly between the second (V2) and third immunisations (V3), leaving some horses insufficiently protected for several weeks. This so-called “immunity gap” poses a challenge to all EI vaccines. During this period, the EI infection of vaccinated animals may be followed by marked clinical signs and virus shedding. However, several EI vaccines have been shown to stimulate equine influenza virus (EIV)-specific cell-mediated immunity, which is likely to play a role in protection against EIV infection and/or mitigate the clinical and virological signs of EI. Reducing the interval between V2 and V3 has been shown to be counterproductive to longer-term immunity. Further research is needed to define and address the “immunity gap” in horses. This study aimed to measure the level of protection induced by a whole inactivated, ISCOMatrix adjuvanted, EI and tetanus vaccine (Equilis Prequenza-Te) when challenged during the immunity gap (i.e., immediately before the recommended boost immunisation, more than 5 months after V2) using infection with a recent heterologous Florida Clade 2 (FC2) equine influenza virus (EIV) strain. This vaccine was tested in a Welsh mountain pony model. A group of seven ponies was vaccinated twice, 4 weeks apart. The protective antibody response was measured and ponies were challenged, along with 5 unvaccinated control ponies, by experimental infection with the FC2 A/eq/Northamptonshire/1/13 EIV strain, 158 days (around 5.2 months) after V2 and their clinical signs and virus shedding were monitored. EI serology was measured by single radial haemolysis (SRH) and haemagglutination inhibition (HI). Clinical signs and virus shedding (measured by qRT-PCR and hen’s egg titration) were compared with controls. All vaccinates had detectable, low SRH antibody titres and most had detectable, low HI titres. Significant clinical and virological protection was observed in vaccinates (p < 0.05), supporting the good performance of this vaccine against a recent EIV strain. In this study, the impact of the immunity gap in ponies was limited after primary vaccination with this whole inactivated, ISCOMatrix adjuvanted EI and tetanus vaccine (Equilis Prequenza-Te) when infected several months after V2 with a recent FC2 strain, which is representative of EIV circulating in the EU.
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Gahan J, Garvey M, Gildea S, Gür E, Kagankaya A, Cullinane A. Whole-genome sequencing and antigenic analysis of the first equine influenza virus identified in Turkey. Influenza Other Respir Viruses 2018; 12:374-382. [PMID: 28940727 PMCID: PMC5907808 DOI: 10.1111/irv.12485] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/26/2017] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND In 2013, there was an outbreak of acute respiratory disease in racehorses in Turkey. The clinical signs were consistent with equine influenza (EI). OBJECTIVE The aim was to confirm the cause of the outbreak and characterise the causal virus. METHODS A pan-reactive influenza type A real-time RT-PCR and a rapid antigen detection kit were used for confirmatory diagnosis of equine influenza virus (EIV). Immunological susceptibility to EIV was examined using single radial haemolysis and ELISA. Antigenic characterisation was completed by haemagglutinin inhibition using a panel of specific ferret antisera. Genetic characterisation was achieved by whole-genome sequencing using segment-specific primers with M13 tags. RESULTS A H3N8 EIV of the Florida clade 2 sublineage (FC2) was confirmed as the causal agent. The index cases were unvaccinated and immunologically susceptible. Phylogenetic analysis of the HA1 and NA genes demonstrated that A/equine/Ankara/1/2013 clustered with the FC2 strains circulating in Europe. Antigenic characterisation confirmed the FC2 classification and demonstrated the absence of significant drift. Whole-genome sequencing indicated that A/equine/Ankara/1/2013 is most closely related to the viruses described as the 179 group based on the substitution I179V in HA1, for example A/equine/East Renfrewshire/2/2011, A/equine/Cambremer/1/2012 and A/equine/Saone et Loire/1/2015. The greatest diversity was observed in the NS1 segment and the polymerase complex. CONCLUSIONS The first recorded outbreak of EI in Turkey was caused by an FC2 virus closely related to viruses circulating in Europe. Antigenic and genetic characterisation gave no indication that the current OIE recommendations for EI vaccine composition require modification.
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Affiliation(s)
| | | | | | - Emre Gür
- Head of Equine Health and Veterinary Services DepartmentJockey Club of TurkeyIstanbulTurkey
| | - Anil Kagankaya
- Department of SurgeryAnkara University Faculty of Veterinary MedicineAnkaraTurkey
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15
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Gildea S, Garvey M, Lyons P, Lyons R, Gahan J, Walsh C, Cullinane A. Multifocal Equine Influenza Outbreak with Vaccination Breakdown in Thoroughbred Racehorses. Pathogens 2018; 7:pathogens7020043. [PMID: 29673169 PMCID: PMC6027538 DOI: 10.3390/pathogens7020043] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Revised: 04/10/2018] [Accepted: 04/13/2018] [Indexed: 01/24/2023] Open
Abstract
Equine influenza (EI) outbreaks occurred on 19 premises in Ireland during 2014. Disease affected thoroughbred (TB) and non-TB horses/ponies on a variety of premises including four racing yards. Initial clinical signs presented on 16 premises within a two-month period. Extensive field investigations were undertaken, and the diagnostic effectiveness of a TaqMan RT-PCR assay was demonstrated in regularly-vaccinated and sub-clinically-affected horses. Epidemiological data and repeat clinical samples were collected from 305 horses, of which 40% were reported as clinically affected, 39% were identified as confirmed cases and 11% were sub-clinically affected. Multivariable analysis demonstrated a significant association between clinical signs and age, vaccination status and number of vaccine doses received. Vaccine breakdown was identified in 31% of horses with up to date vaccination records. This included 27 horses in four different racing yards. Genetic and antigenic analysis identified causal viruses as belonging to Clade 2 of the Florida sublineage (FCL2). At the time of this study, no commercially available EI vaccine in Ireland had been updated in line with World Organisation for Animal Health (OIE) recommendations to include a FCL2 virus. The findings of this study highlight the potential ease with which EI can spread among partially immune equine populations.
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Affiliation(s)
- Sarah Gildea
- Virology Unit, The Irish Equine Centre, Johnstown, Naas, Co. Kildare W91 RH93, Ireland.
| | - Marie Garvey
- Virology Unit, The Irish Equine Centre, Johnstown, Naas, Co. Kildare W91 RH93, Ireland.
| | - Pamela Lyons
- Virology Unit, The Irish Equine Centre, Johnstown, Naas, Co. Kildare W91 RH93, Ireland.
| | - Rachel Lyons
- Virology Unit, The Irish Equine Centre, Johnstown, Naas, Co. Kildare W91 RH93, Ireland.
| | - Jacinta Gahan
- Virology Unit, The Irish Equine Centre, Johnstown, Naas, Co. Kildare W91 RH93, Ireland.
| | - Cathal Walsh
- Department of Mathematics and Statistics, University of Limerick, Castletroy, Limerick V94 T9PX, Ireland.
| | - Ann Cullinane
- Virology Unit, The Irish Equine Centre, Johnstown, Naas, Co. Kildare W91 RH93, Ireland.
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16
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Equine Vaccines: How, When and Why? Report of the Vaccinology Session, French Equine Veterinarians Association, 2016, Reims. Vaccines (Basel) 2017; 5:vaccines5040046. [PMID: 29207516 PMCID: PMC5748612 DOI: 10.3390/vaccines5040046] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Revised: 11/15/2017] [Accepted: 11/29/2017] [Indexed: 11/21/2022] Open
Abstract
To date, vaccination is one of the most efficient methods of prevention against equine infectious diseases. The vaccinology session, which was organised during the annual meeting of the French Equine Veterinarians Association (AVEF) at Reims (France) in 2016, aimed to approach three subjects of importance for the equine industry. Vaccination against three major equine diseases were used as examples: equine influenza (equine influenza virus), rhinopneumonitis (equine herpes virus 1/4), and tetanus (Clostridium tetani neuro-toxin). (1) Emergency vaccination: while it has been very successful to reduce the impact of equine influenza epizooties and it is also recommended for tetanus in case of surgery and accident, the benefit of emergency vaccination against equine herpes virus 1/4 remains arguable; (2) Compatibility of equine vaccines from different brands: despite being a frequent concerns for equine veterinarians, little information is available about the compatibility of equine vaccines from different commercial origins. The consequence of mixing different equine vaccines targeting the same disease is believed to be limited but scientific evidences are sparse; and, (3) Laps vaccination and vaccine shortage: they could have serious consequences in terms of protection and their impact should be evaluated on a case by case basis, taking into account the risk of contact with the pathogen and the effect on herd immunity.
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17
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18
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Ryan M, Gildea S, Walsh C, Cullinane A. The impact of different equine influenza vaccine products and other factors on equine influenza antibody levels in Thoroughbred racehorses. Equine Vet J 2014; 47:662-6. [DOI: 10.1111/evj.12353] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Accepted: 09/01/2014] [Indexed: 11/27/2022]
Affiliation(s)
- M. Ryan
- Virology Unit; The Irish Equine Centre; Johnstown, Naas, Co. Kildare Ireland
| | - S. Gildea
- Virology Unit; The Irish Equine Centre; Johnstown, Naas, Co. Kildare Ireland
| | - C. Walsh
- Department of Statistics; Trinity College; Dublin Ireland
| | - A. Cullinane
- Virology Unit; The Irish Equine Centre; Johnstown, Naas, Co. Kildare Ireland
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A Systematic Review of Recent Advances in Equine Influenza Vaccination. Vaccines (Basel) 2014; 2:797-831. [PMID: 26344892 PMCID: PMC4494246 DOI: 10.3390/vaccines2040797] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2014] [Revised: 09/19/2014] [Accepted: 09/24/2014] [Indexed: 01/28/2023] Open
Abstract
Equine influenza (EI) is a major respiratory disease of horses, which is still causing substantial outbreaks worldwide despite several decades of surveillance and prevention. Alongside quarantine procedures, vaccination is widely used to prevent or limit spread of the disease. The panel of EI vaccines commercially available is probably one of the most varied, including whole inactivated virus vaccines, Immuno-Stimulating Complex adjuvanted vaccines (ISCOM and ISCOM-Matrix), a live attenuated equine influenza virus (EIV) vaccine and a recombinant poxvirus-vectored vaccine. Several other strategies of vaccination are also evaluated. This systematic review reports the advances of EI vaccines during the last few years as well as some of the mechanisms behind the inefficient or sub-optimal response of horses to vaccination.
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20
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Slater J, Borchers K, Chambers T, Cullinane A, Duggan V, Elton D, Legrand L, Paillot R, Fortier G. Report of the International Equine Influenza Roundtable Expert Meeting at Le Touquet, Normandy, February 2013. Equine Vet J 2014; 46:645-50. [PMID: 25146166 DOI: 10.1111/evj.12302] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- J Slater
- Royal Veterinary College, London, UK
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