Chorioallantoic membranes of embryonated chicken eggs as an alternative system for isolation of equine influenza virus

Vaccination is an effective method for the prevention of influenza virus infection. Many manufacturers use embryonated chicken eggs (ECE) for the propagation of vaccine strains. However, the adaptation of viral strains during subsequent passages can lead to additional virus evolution and lower effectiveness of the resulting vaccines. In our study, we analyzed the distribution of single nucleotide variants (SNVs) of equine influenza virus (EIV) during passaging in ECE. Viral RNA from passage 0 (nasal swabs), passage 2 and 5 was sequenced using next generation technology. In total, 50 SNVs with an occurrence frequency above 2% were observed, 29 of which resulted in amino acid changes. The highest variability was found in passage 2, with the most variable segment being IV encoding hemagglutinin (HA). Three variants, HA (W222G), PB2 (A377E) and PA (R531K), had clearly increased frequency with the subsequent passages, becoming dominant. None of the five nonsynonymous HA variants directly affected the major antigenic sites; however, S227P was previously reported to influence the antigenicity of EIV. Our results suggest that although host-specific adaptation was observed in low passages of EIV in ECE, it should not pose a significant risk to influenza vaccine efficacy.

Download Full-text

Protein expression changes in cells inoculated with Equine Influenza Virus: antibody microarray analysis

Polish Journal of Veterinary Sciences ◽

10.2478/pjvs-2013-0094 ◽

2013 ◽

Vol 16 (4) ◽

pp. 663-669

Author(s):

W. Rozek ◽

M. Kwasnik ◽

J.F. Zmudzinski

Keyword(s):

Influenza Virus ◽

Protein Quality ◽

Biological Properties ◽

Regulation Of Transcription ◽

Equine Influenza Virus ◽

Virus Antibody ◽

Antibody Microarray ◽

Equine Influenza ◽

Microarray Technique ◽

In Cells

AbstractChanges in the level of cellular proteins in cells inoculated with equine influenza virus H7N7 and H3N8 were studied with microarray technique. H3N8 induced pro-apoptotic proteins while H7N7 induced both pro- as well as anti-apoptotic factors. The higher level of some cytoskeleton components and proteins involved in the protein quality control was recorded. Relatively high number of proteins involved in the regulation of transcription was down-regulated. The pattern of changes observed for H7N7 and H3N8 may reflect differences in the biological properties of both serotypes.

Download Full-text

Comparative measurement of Equine influenza virus antibodies by single radial haemolysis and haemagglutination inhibition tests

Journal of Current Veterinary Research ◽

10.21608/jcvr.2016.37889 ◽

2016 ◽

Vol 10 (1) ◽

pp. 72-79

Author(s):

Eman Ebeid ◽

Nehal Saleh ◽

Nashwa Madkour

Keyword(s):

Influenza Virus ◽

Haemagglutination Inhibition ◽

Equine Influenza Virus ◽

Comparative Measurement ◽

Equine Influenza

Download Full-text

Protection against the New Equine Influenza Virus Florida Clade I Outbreak Strain Provided by a Whole Inactivated Virus Vaccine

Vaccines ◽

10.3390/vaccines8040784 ◽

2020 ◽

Vol 8 (4) ◽

pp. 784

Author(s):

Sylvia Reemers ◽

Sander van Bommel ◽

Qi Cao ◽

David Sutton ◽

Saskia van de Zande

Keyword(s):

Influenza Virus ◽

Virus Vaccine ◽

Clinical Signs ◽

Field Strain ◽

Equine Influenza Virus ◽

Outbreak Strain ◽

Virus Shedding ◽

Equine Influenza ◽

Vaccine Type ◽

High Level

Equine influenza virus (EIV) is a major cause of respiratory disease in horses. Vaccination is an effective tool for infection control. Although various EIV vaccines are widely available, major outbreaks occurred in Europe in 2018 involving a new EIV H3N8 FC1 strain. In France, it was reported that both unvaccinated and vaccinated horses were affected despite >80% vaccination coverage and most horses being vaccinated with a vaccine expressing FC1 antigen. This study assessed whether vaccine type, next to antigenic difference between vaccine and field strain, plays a role. Horses were vaccinated with an ISCOMatrix-adjuvanted, whole inactivated virus vaccine (Equilis Prequenza) and experimentally infected with the new FC1 outbreak strain. Serology (HI), clinical signs, and virus shedding were evaluated in vaccinated compared to unvaccinated horses. Results showed a significant reduction in clinical signs and a lack of virus shedding in vaccinated horses compared to unvaccinated controls. From these results, it can be concluded that Equilis Prequenza provides a high level of protection to challenge with the new FC1 outbreak strain. This suggests that, apart from antigenic differences between vaccine and field strain, other aspects of the vaccine may also play an important role in determining field efficacy.

Download Full-text

PREVALENCE OF ANTIBODIES AGAINST INFLUENZA VIRUS IN NON-VACCINATED EQUINES FROM THE BRAZILIAN PANTANAL

Revista do Instituto de Medicina Tropical de São Paulo ◽

10.1590/s0036-46652014000600006 ◽

2014 ◽

Vol 56 (6) ◽

pp. 487-492 ◽

Cited By ~ 5

Author(s):

Lucas Gaíva E Silva ◽

Alice Mamede Costa Marques Borges ◽

Eliana Monteforte Cassaro Villalobos ◽

Maria do Carmo Custodio Souza Hunold Lara ◽

Elenice Maria Siquetin Cunha ◽

...

Keyword(s):

Influenza Virus ◽

Equine Infectious Anemia Virus ◽

Linear Regression Models ◽

Equine Influenza Virus ◽

Chi Square ◽

Equine Influenza ◽

Hemagglutination Inhibition Test ◽

Chi Square Test ◽

Spatial Autoregressive ◽

Anemia Virus

The prevalence of antibodies against Equine Influenza Virus (EIV) was determined in 529 equines living on ranches in the municipality of Poconé, Pantanal area of Brazil, by means of the hemagglutination inhibition test, using subtype H3N8 as antigen. The distribution and possible association among positive animal and ranches were evaluated by the chi-square test, spatial autoregressive and multiple linear regression models. The prevalence of antibodies against EIV was estimated at 45.2% (95% CI 30.2 - 61.1%) with titers ranging from 20 to 1,280 HAU. Seropositive equines were found on 92.0% of the surveyed ranches. Equine from non-flooded ranches (66.5%) and negativity in equine infectious anemia virus (EIAV) (61.7%) were associated with antibodies against EIV. No spatial correlation was found among the ranches, but the ones located in non-flooded areas were associated with antibodies against EIV. A negative correlation was found between the prevalence of antibodies against EIV and the presence of EIAV positive animals on the ranches. The high prevalence of antibodies against EIV detected in this study suggests that the virus is circulating among the animals, and this statistical analysis indicates that the movement and aggregation of animals are factors associated to the transmission of the virus in the region.

Download Full-text