Evolution of Equine Influenza Virus in Vaccinated Horses (original) (raw)
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Vaccines
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...
2004
Two lineages of antigenically distinct equine influenza A H3N8 subtype viruses, American and European, co-circulate. Experiments were conducted in ponies to investigate the protection induced by vaccines containing virus from one lineage against challenge infection with homologous or heterologous virus. Regression analysis showed that vaccinated ponies with average pre-challenge single radial haemolysis (SRH) antibody levels (i.e. 45-190 mm 2) had a higher probability of becoming infected if they were vaccinated with virus heterologous to the challenge strain than if they were vaccinated with homologous virus. Field studies in Thoroughbred racehorses also showed that SRH antibody levels of ≥150 mm 2 induced by vaccines containing a European lineage strain are protective against infection with a virus from the same lineage, but that the same or higher antibody levels may not be protective against an American lineage virus. In conclusion, vaccines should contain virus strains representative of both H3N8 subtype lineages to maximise protection against infection.
Trakia Journal of Science, 2015
PURPOSE: The purpose of the present study was to evaluate the effects of booster vaccination of horses with multivalent vaccine against equine herpes virus 4/1 and equine influenza virus (EIV) on some acute phase response indicesclassical pathway of complement activation (CPCA), erythrocyte sedimentation rate (ESR) and some clinical parameters. METHODS: Nine Hanoverian geldings were divided into two groups: group А-3 non-vaccinated animals and group B-6 revaccinated animals. Horses from group B were vaccinated one year ago against EHV 4/1 and EIV. CPCA was assayed as per the method of Mayer, modified for horses and ESR-by the method of Westergren. Pulse rate (PR), respiratory rate (RR) and rectal temperature (RT) were also monitored throughout the 14-day experimental period. RESULTS: In horses from group B, a substantial increase in haemolytic activity of CPCA was established (24-72 h), enhanced ESR (by the 72 nd h), accelerated PR by the 24 th h within the reference range, no statistically significant changes in RR and absence of fever. CONCLUSIONS: The changes in acute phase response parameters CPCA, ESR, PR, RR and RT after revaccination of horses could provide information for their health status with respect to their performance and participation in competitions.
Effect of influenza A/Equine/H3N8 isolate variation on the measurement of equine antibody responses
Canadian journal of veterinary research = Revue canadienne de recherche vétérinaire
This study has tested the effect of using homologous or heterologous equine influenza A virus isolates to evaluate serum antibody levels to influenza A virus in vaccinated and naturally-infected horses. In addition, the potential effect of antigenic selection of virus variants in egg versus tissue culture propagation systems was studied. Serum antibody levels in samples from horses recently infected with a local influenza A virus isolate (A/equine 2/Saskatoon/1/90) or recently vaccinated with a prototype isolate (A/equine 2/Miami/1/63) were assessed by hemagglutination inhibition and by single radial hemolysis using cell or egg-propagated A
EVIDENCE OF HUMAN-EQUINE INTERSPECIES INFLUENZA TRANSMISSION
VIRUS Reviews & Research, 2006
High levels of antibodies against the human influenza A(H 1 N 1 ) and A(H 3 N 2 ) strains in horse sera have been reported. The aim of the present study was to survey the human influenza virus strains present in horses using two methodologies, viral isolation and serology.
Veterinary Immunology and Immunopathology, 2010
Equine influenza virus remains an important problem in horses despite extensive use of vaccination. Efficacy of equine influenza vaccination depends on the onset and duration of protective immunity, and appropriate strain specificity of the immune response. This study was designed to test the protective immunity resulting from vaccination with the North American commercial ALVAC 1 equine influenza vaccine (RECOMBITEK 1 Influenza, Merial, USA) 1 against challenge with American lineage influenza viruses. In experiment 1, 12 ponies were vaccinated twice, at a 35 day interval, using the ALVAC 1-influenza vaccine expressing the HA genes of influenza A/eq/Newmarket/2/93 and A/eq/Kentucky/94 (H3N8), and 11 ponies served as unvaccinated controls. Six months after the second vaccination, all ponies were challenged with A/eq/Kentucky/91. In experiment 2, 10 ponies received one dose of the ALVAC 1-influenza vaccine, 10 ponies served as unvaccinated controls, and all ponies were challenge infected with A/equine/Ohio/03, 14 days after vaccination. Parameters studied included serological responses, and clinical disease and nasal viral shedding following challenge infection. In experiment 1, following the twodose regimen, vaccinated ponies generated high titered anti-influenza virus IgGa and IgGb antibody responses to vaccination and demonstrated statistically significant clinical and virological protection to challenge infection compared to controls. Infection with A/eq/ Kentucky/91 produced unusually severe signs in ponies in the control group, requiring therapy with NSAID's and antibiotics, and leading to the euthanasia of one pony. In experiment 2 following the one-dose regimen, vaccinates generated IgGa responses prechallenge, and anamnestic IgGa and IgGb responses after challenge. Vaccinates demonstrated statistically significant clinical and virological protection to challenge infection compared to controls. The results of this study clearly demonstrate the early onset, and 6-month duration of protective immunity resulting from ALVAC 1-influenza vaccination against challenge with American lineage equine influenza viruses.
Anti-human influenza protector antibody detected in horses as a zoonotic viruses
Brazilian Journal of Veterinary Research and Animal Science, 2004
This study aimed to investigate the incidence of the influenza virus, and its interspecies transmission cycle among horses. A comparative serological survey was performed using horse sera following challenge with both specific (equine) and non-specific (human) influenza virus strains. Bleedings of the 22 horses were performed during the years 1999 and 2000. Following treatment with kaolin (20%), added in rooster erythrocytes suspension (50%), for removal of non-specific antibodies, sera were titered against both Human and Equine Influenza virus, by the Hemagglutination Inhibition Assay(HI), recommended by WHO. The HI results of horse serological responses demonstrate cross reaction between both the specific strain, A/Eq1 (H7N7) ( 62.75%) and A/Eq2 (H3N8) (60.65%), and the non-specific strains, type A (H1N1) (79.5%) and A (H3N2) (94.45%) and type B (77.75%). It was noteworthy the high percentage of protection responses in equine sera aginst the non-specific strains, as compared with the specific strains. This finding suggests direct interspecies transmission of influenza virus as zoonotic viruses, particulary for the type B strain which is considered restricted to humans. It was the first report, in Brazil. Further studies are required to achieve a complete understanding of the incidence of influenza in our environment.
Canadian journal of veterinary research = Revue canadienne de recherche vétérinaire, 1997
The purpose of this experiment was to study the duration and distribution of equine influenza virus in actively infected ponies over a 3 wk period. Pony foals (6-8 mo old) were infected experimentally by nebulizing equine influenza subtype-2 virus ultrasonically through a face mask. Successful infection was clinically apparent as each of the foals (n = 6) had a febrile response, a deep hacking cough and mucopurulent nasal discharge for 7 to 10 d. The virus was isolated from nasopharyngeal swabs of all the ponies 3 and 5 d after infection and all the ponies seroconverted to the virus. Samples were taken from the nasopharynx, mid-trachea and the mainstem bronchus with cytology brushes through an endoscope as well as from bronchoalveolar lavage fluid. On days 3 to 7 post-infection, ciliacytophtorea (the presence of cilia and ciliated plates separated from columnar epithelial cells) was recognized on routine cytological stain. Indirect immunoperoxidase staining utilizing polyclonal anti...
Impact of Mixed Equine Influenza Vaccination on Correlate of Protection in Horses
Vaccines
To evaluate the humoral immune response to mixed Equine Influenza vaccination, a common practice in the field, an experimental study was carried out on 42 unvaccinated thoroughbred weanling foals divided into six groups of seven. Three groups were vaccinated using a non-mixed protocol (Equilis® Prequenza-Te, Proteqflu-Te® or Calvenza-03®) and three other groups were vaccinated using a mix of the three vaccines mentioned previously. Each weanling underwent a primary EI vaccination schedule composed of two primary immunisations (V1 and V2) four weeks apart followed by a third boost immunisation (V3) six months later. Antibody responses were monitored until one-year post-V3 by single radial haemolysis (SRH). The results showed similar antibody responses for all groups using mixed EI vaccination and the group exclusively vaccinated with Equilis® Prequenza-TE, which were significantly higher than the other two groups vaccinated with Proteqflu-TE® and Calvenza-03®. All weanlings (100%) fa...
Animals
Huculs (Equus caballus) are an old breed of primitive mountain horses, originating from the Carpathian Mountains. To the best of our knowledge, data concerning the epidemiology of viral infections observed within this breed are sparse. The objective of this study was to estimate the serological status of a semi-isolated, unvaccinated Hucul herd, with respect to both common equine viral infections and horse-infecting arboviruses, the presence of which was previously reported in Poland. Twenty horses of the Hucul breed, living in a remote area in Poland, were studied in 2018 from March to May. Using nasal secretion swabs as a specimen source, isolation attempts were negative regarding ERAV, EHV-1, EAV, and EIV. According to the virus neutralisation method, in the sera obtained from the animals, antibodies against the following viruses were detected: EHV-1 in 12 horses (60%; with titres from 1:8 to 1:64), EIV A/H7N7 in 13 (65%; titres from 1:20 to 1:80), EIV A /H3N8 in 12 (60%; titres ...