Evolution of equine influenza viruses (H3N8) during a Brazilian outbreak, 2015

Favaro, Patrícia Filippsen; Fernandes, Wilson Roberto; Reischak, Dilmara; Brandão, Paulo Eduardo; Silva, Sheila Oliveira de Souza; Richtzenhain, Leonardo José

doi:10.1016/j.bjm.2017.07.003

Cited by 14 publications

(23 citation statements)

References 32 publications

(55 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Antibodies were measured by single radial hemolysis (SRH) assay against the EIV strain A/equine/Jouars/4/06 (H3N8; Florida Clade 2), as previously described [16]. A control reference serum (A/equine/South Africa/4/03; H3N8; Florida Clade 1; reference Eu SA/4/03 Y0000712) from the European Directorate for the Quality of Medicines and Healthcare (EDQM) was included on each plate and used to standardize the results [21].…”

Section: Single Radial Haemolysis (Srh)mentioning

confidence: 99%

Success and Limitation of Equine Influenza Vaccination: The First Incursion in a Decade of a Florida Clade 1 Equine Influenza Virus that Shakes Protection Despite High Vaccine Coverage

et al. 2019

View full text Add to dashboard Cite

Every year, several epizooties of equine influenza (EI) are reported worldwide. However, no EI case has been identified in France between 2015 and late 2018, despite an effective field surveillance of the pathogen and the disease. Vaccination against equine influenza virus (EIV) remains to this day one of the most effective methods to prevent or limit EI outbreaks and the lack of detection of the pathogen could be linked to vaccination coverage. The aim of this study was to evaluate EI immunity and vaccine coverage in France through a large-scale serological study. A total of 3004 archived surplus serums from French horses of all ages, breeds and sexes were selected from four different geographical regions and categories (i.e., sanitary check prior to exportation, sale, breeding protocol or illness diagnosis). EIV-specific antibody response was measured by single radial hemolysis (SRH) and an EIV-nucleoprotein (NP) ELISA (used as a DIVA test). Overall immunity coverage against EIV infection (i.e., titers induced by vaccination and/or natural infection above the clinical protection threshold) reached 87.6%. The EIV NP ELISA results showed that 83% of SRH positive serum samples from young horses (≤3 years old) did not have NP antibodies, which indicates that the SRH antibody response was likely induced by EI vaccination alone (the HA recombinant canarypoxvirus-based EI vaccine is mostly used in France) and supports the absence of EIV circulation in French horse populations between 2015 and late 2018, as reported by the French equine infectious diseases surveillance network (RESPE). Results from this study confirm a strong EI immunity in a large cohort of French horses, which provides an explanation to the lack of clinical EI in France in recent years and highlights the success of vaccination against this disease. However, such EI protection has been challenged since late 2018 by the incursion in the EU of a Florida Clade 1 sub-lineage EIV (undetected in France since 2009), which is also reported here.

show abstract

Section: Single Radial Haemolysis (Srh)mentioning

confidence: 99%

Success and Limitation of Equine Influenza Vaccination: The First Incursion in a Decade of a Florida Clade 1 Equine Influenza Virus that Shakes Protection Despite High Vaccine Coverage

et al. 2019

View full text Add to dashboard Cite

show abstract

“…Heterotypic immunity is provided at minimum level by humoral responses; whereas cross-reactive response (mediated by cytotoxic T lymphocytes) is observed between the viral subtypes, true for all the subtypes of type A viruses (Hemann et al, 2013 ; McKinstry et al, 2013 ; Landolt, 2014 ). Subtle changes in the constitution of amino acid may result in immune escape due to different antigenicity (Park et al, 2009 ) and recently, it has been revealed that there are nine substitutions in the sequences of HA of Brazilian EIV isolates in comparison to the vaccine strain (Florida Clade 1; Favaro et al, 2018 ).…”

Section: Etiologymentioning

confidence: 99%

A Comprehensive Review on Equine Influenza Virus: Etiology, Epidemiology, Pathobiology, Advances in Developing Diagnostics, Vaccines, and Control Strategies

et al. 2018

View full text Add to dashboard Cite

Among all the emerging and re-emerging animal diseases, influenza group is the prototype member associated with severe respiratory infections in wide host species. Wherein, Equine influenza (EI) is the main cause of respiratory illness in equines across globe and is caused by equine influenza A virus (EIV-A) which has impacted the equine industry internationally due to high morbidity and marginal morality. The virus transmits easily by direct contact and inhalation making its spread global and leaving only limited areas untouched. Hitherto reports confirm that this virus crosses the species barriers and found to affect canines and few other animal species (cat and camel). EIV is continuously evolving with changes at the amino acid level wreaking the control program a tedious task. Until now, no natural EI origin infections have been reported explicitly in humans. Recent advances in the diagnostics have led to efficient surveillance and rapid detection of EIV infections at the onset of outbreaks. Incessant surveillance programs will aid in opting a better control strategy for this virus by updating the circulating vaccine strains. Recurrent vaccination failures against this virus due to antigenic drift and shift have been disappointing, however better understanding of the virus pathogenesis would make it easier to design effective vaccines predominantly targeting the conserved epitopes (HA glycoprotein). Additionally, the cold adapted and canarypox vectored vaccines are proving effective in ceasing the severity of disease. Furthermore, better understanding of its genetics and molecular biology will help in estimating the rate of evolution and occurrence of pandemics in future. Here, we highlight the advances occurred in understanding the etiology, epidemiology and pathobiology of EIV and a special focus is on designing and developing effective diagnostics, vaccines and control strategies for mitigating the emerging menace by EIV.

show abstract

“…Nowadays, the Florida sublineage is predominant and has diverged into Florida clade 1 and Florida clade 2 . Florida clade 1 viruses have been isolated in many countries including Chile, Brazil, Uruguay and Argentina . Florida clade 2 strains are commonly found in Europe but have been also identified in Asian countries .…”

Section: Introductionmentioning

confidence: 99%

Multifocal outbreak of equine influenza in vaccinated horses in Argentina in 2018: Epidemiological aspects and molecular characterisation of the involved virus strains

Perglione

Vissani

Alamos

et al. 2019

Equine Veterinary Journal

View full text Add to dashboard Cite

Summary Background Equine influenza is an important cause of respiratory disease of horses worldwide. The equine influenza virus (EIV) undergoes antigenic drift through the accumulation of amino acid substitutions in the viral proteins, which may lead to vaccine breakdown. Objectives To describe the epidemiological findings and the molecular characteristics of the EIV detected during the multifocal outbreak that occurred in Argentina between March and July 2018 and evidence a vaccine breakdown. Study design Observational, descriptive study. Methods Virus was detected in nasopharyngeal swabs using real‐time reverse transcriptase PCR (RT‐PCR). Nucleotide and deduced amino acid sequences of the haemagglutinin (HA) and neuraminidase (NA) genes were obtained from EIV positive nasopharyngeal swabs, and phylogenetic analysis was undertaken. Amino acid sequences were compared against the current World Organisation for Animal Health (OIE)‐recommended Florida clade 1 vaccine strain and strain components of vaccines used in Argentina. Serum samples were tested using haemagglutination inhibition test. Results Equine influenza virus infection was confirmed using real‐time RT‐PCR and serological testing. The phylogenetic analysis of the HA and NA genes revealed that all the EIV identified during the outbreak belong to the H3N8 subtype, Florida clade 1. Multiple amino acid changes, some of them at antigenic sites, were observed in the circulating virus when compared with the strains included in the most commonly used vaccine in Argentina. Seventy‐six percent of the affected horses had been vaccinated with this vaccine, suggesting the occurrence of vaccine breakdown. Main limitations The study does not include antigenic characterisation and full genome sequencing of Argentinian strains, that could provide additional information. Conclusions The occurrence of this multifocal equine influenza outbreak in regularly vaccinated horses is a field evidence of vaccine breakdown, reinforcing the necessity of keeping vaccine strains updated according to OIE recommendations. It also underlines the importance of the implementation of appropriate quarantine measures and restriction of horse movement in the face of disease.

show abstract

Evolution of equine influenza viruses (H3N8) during a Brazilian outbreak, 2015

Cited by 14 publications

References 32 publications

Success and Limitation of Equine Influenza Vaccination: The First Incursion in a Decade of a Florida Clade 1 Equine Influenza Virus that Shakes Protection Despite High Vaccine Coverage

Success and Limitation of Equine Influenza Vaccination: The First Incursion in a Decade of a Florida Clade 1 Equine Influenza Virus that Shakes Protection Despite High Vaccine Coverage

A Comprehensive Review on Equine Influenza Virus: Etiology, Epidemiology, Pathobiology, Advances in Developing Diagnostics, Vaccines, and Control Strategies

Multifocal outbreak of equine influenza in vaccinated horses in Argentina in 2018: Epidemiological aspects and molecular characterisation of the involved virus strains

Contact Info

Product

Resources

About