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A Systematic Review of Recent Advances in Equine Influenza Vaccination.

Paillot R - Vaccines (Basel) (2014)

Bottom Line: Equine influenza (EI) is a major respiratory disease of horses, which is still causing substantial outbreaks worldwide despite several decades of surveillance and prevention.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.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.

View Article: PubMed Central - PubMed

Affiliation: Animal Health Trust, Centre for Preventive Medicine, Lanwades Park, Newmarket, Suffolk CB8 7UU, UK. romain.paillot@aht.org.uk.

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.

No MeSH data available.


Related in: MedlinePlus

(A) EIV structure; (B) The reproductive cycle of influenza A virus. The virus binds to receptors on the surface of the cells (1) and is internalized into endosomes (2). Modification of pH in both the endosome and the virus induces fusion and uncoating of the virus (3). vRNP are released into the cytoplasm and imported into the nucleus where their replication takes place (4). mRNA are produced and exported into the cytoplasm for protein synthesis (5). This is controlled by NS1. These viral proteins will either assist replication of the virus and formation of vRNP into the nucleus (6), or form new viruses at the cell surface (7). Progeny viruses are assembled and bud from the cell membrane (8). CF = complement fixing; VN = virus neutralising.
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vaccines-02-00797-f002: (A) EIV structure; (B) The reproductive cycle of influenza A virus. The virus binds to receptors on the surface of the cells (1) and is internalized into endosomes (2). Modification of pH in both the endosome and the virus induces fusion and uncoating of the virus (3). vRNP are released into the cytoplasm and imported into the nucleus where their replication takes place (4). mRNA are produced and exported into the cytoplasm for protein synthesis (5). This is controlled by NS1. These viral proteins will either assist replication of the virus and formation of vRNP into the nucleus (6), or form new viruses at the cell surface (7). Progeny viruses are assembled and bud from the cell membrane (8). CF = complement fixing; VN = virus neutralising.

Mentions: Natural or experimental infection with EIV induces protection against re-infection with a homologous or closely related strain for several months [39,40] (reference 40: study sponsored by Horserace Betting Leavy Board), depending on the individual. The level of EIV-specific antibodies, measured by single radial haemolysis (SRH) or haemagglutination inhibition (HI) assays, is a correlate of protection against homologous EIV strains. Reduced clinical signs of disease and resistance to infection with an EIV strain homologous to the vaccine strain were observed in animals with SRH antibody levels of >85 mm² and >120–154 mm², respectively [41,42,43,44]. Current field data still support this correlation [45]. Antibodies specific to influenza virus HA and NA molecules act by neutralising the virus prior to infection of the respiratory epithelium and by inhibiting virus release after replication in infected cells, respectively [1,18] (Figure 2). Virus neutralising (VN) antibodies are essential to limit the spread of the disease [46,47]. Complement fixing (CF) antibodies target EIV infected cells in order to clear the infection. Both HA and NA are important influenza vaccine components. Immunity to EIV HA has been well described. In contrast, NA immunity is poorly characterised in the horse. Vaccination against EIV, which is an efficient method of prevention, relies on the antigenic homogeneity between the vaccine and circulating EIV strains. Therefore, a constant monitoring of the antigenicity of circulating EIV strains is essential to select appropriate vaccine strains and to ensure that vaccines remain up to date. The OIE (World Organisation for Animal Health) expert surveillance panel on EI vaccine annually reviews laboratory and epidemiological data about worldwide EIV circulation. EIV gene sequences (primarily HA and NA) and antigenic variation assessed with predictive tools and models (e.g., immune-reactivity using strain specific ferret sera) and quantified by cartography are analysed in order to anticipate the impact of EIV antigenic drift on vaccine protection, and to deliver an annual recommendation on vaccine strain composition. Since 2011, the recommendation approves the incorporation of both Florida clade 1 and clade 2 EIV representative strains of the Florida sublineage in vaccine [48]. The inclusion of H7N7 virus and H3N8 EIV of the European lineage is no longer supported. These recommendations remained unchanged [11]. To date, one EI vaccine has been fully updated to meet to the current recommendation.


A Systematic Review of Recent Advances in Equine Influenza Vaccination.

Paillot R - Vaccines (Basel) (2014)

(A) EIV structure; (B) The reproductive cycle of influenza A virus. The virus binds to receptors on the surface of the cells (1) and is internalized into endosomes (2). Modification of pH in both the endosome and the virus induces fusion and uncoating of the virus (3). vRNP are released into the cytoplasm and imported into the nucleus where their replication takes place (4). mRNA are produced and exported into the cytoplasm for protein synthesis (5). This is controlled by NS1. These viral proteins will either assist replication of the virus and formation of vRNP into the nucleus (6), or form new viruses at the cell surface (7). Progeny viruses are assembled and bud from the cell membrane (8). CF = complement fixing; VN = virus neutralising.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4494246&req=5

vaccines-02-00797-f002: (A) EIV structure; (B) The reproductive cycle of influenza A virus. The virus binds to receptors on the surface of the cells (1) and is internalized into endosomes (2). Modification of pH in both the endosome and the virus induces fusion and uncoating of the virus (3). vRNP are released into the cytoplasm and imported into the nucleus where their replication takes place (4). mRNA are produced and exported into the cytoplasm for protein synthesis (5). This is controlled by NS1. These viral proteins will either assist replication of the virus and formation of vRNP into the nucleus (6), or form new viruses at the cell surface (7). Progeny viruses are assembled and bud from the cell membrane (8). CF = complement fixing; VN = virus neutralising.
Mentions: Natural or experimental infection with EIV induces protection against re-infection with a homologous or closely related strain for several months [39,40] (reference 40: study sponsored by Horserace Betting Leavy Board), depending on the individual. The level of EIV-specific antibodies, measured by single radial haemolysis (SRH) or haemagglutination inhibition (HI) assays, is a correlate of protection against homologous EIV strains. Reduced clinical signs of disease and resistance to infection with an EIV strain homologous to the vaccine strain were observed in animals with SRH antibody levels of >85 mm² and >120–154 mm², respectively [41,42,43,44]. Current field data still support this correlation [45]. Antibodies specific to influenza virus HA and NA molecules act by neutralising the virus prior to infection of the respiratory epithelium and by inhibiting virus release after replication in infected cells, respectively [1,18] (Figure 2). Virus neutralising (VN) antibodies are essential to limit the spread of the disease [46,47]. Complement fixing (CF) antibodies target EIV infected cells in order to clear the infection. Both HA and NA are important influenza vaccine components. Immunity to EIV HA has been well described. In contrast, NA immunity is poorly characterised in the horse. Vaccination against EIV, which is an efficient method of prevention, relies on the antigenic homogeneity between the vaccine and circulating EIV strains. Therefore, a constant monitoring of the antigenicity of circulating EIV strains is essential to select appropriate vaccine strains and to ensure that vaccines remain up to date. The OIE (World Organisation for Animal Health) expert surveillance panel on EI vaccine annually reviews laboratory and epidemiological data about worldwide EIV circulation. EIV gene sequences (primarily HA and NA) and antigenic variation assessed with predictive tools and models (e.g., immune-reactivity using strain specific ferret sera) and quantified by cartography are analysed in order to anticipate the impact of EIV antigenic drift on vaccine protection, and to deliver an annual recommendation on vaccine strain composition. Since 2011, the recommendation approves the incorporation of both Florida clade 1 and clade 2 EIV representative strains of the Florida sublineage in vaccine [48]. The inclusion of H7N7 virus and H3N8 EIV of the European lineage is no longer supported. These recommendations remained unchanged [11]. To date, one EI vaccine has been fully updated to meet to the current recommendation.

Bottom Line: Equine influenza (EI) is a major respiratory disease of horses, which is still causing substantial outbreaks worldwide despite several decades of surveillance and prevention.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.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.

View Article: PubMed Central - PubMed

Affiliation: Animal Health Trust, Centre for Preventive Medicine, Lanwades Park, Newmarket, Suffolk CB8 7UU, UK. romain.paillot@aht.org.uk.

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.

No MeSH data available.


Related in: MedlinePlus