Efficacy of a non-updated, Matrix-C-based equine influenza subunit-tetanus vaccine following Florida sublineage clade 2 challenge.

Abstract

Assessing the ability of current equine influenza vaccines to provide cross-protection against emerging strains is important. Horses not vaccinated previously and seronegative for equine influenza based on haemagglutination inhibition (HI) assay were assigned at random to vaccinated (n=7) or non-vaccinated (control, n=5) groups. Vaccination was performed twice four weeks apart with a 1 ml influenza subunit (A/eq/Prague/1/56, A/eq/Newmarket/1/93, A/eq/Newmarket/2/93), tetanus toxoid vaccine with Matrix-C adjuvant (EquilisPrequenza Te). All the horses were challenged individually by aerosol with A/eq/Richmond/1/07 three weeks after the second vaccination. Rectal temperature, clinical signs, serology and virus excretion were monitored for 14 days after challenge. There was no pain at the injection site or increases in rectal temperature following vaccination. Increases in rectal temperature and characteristic clinical signs were recorded in the control horses. Clinical signs were minimal in vaccinated horses. Clinical (P=0.0345) and total clinical scores (P=0.0180) were significantly lower in the vaccinated than in the control horses. Vaccination had a significant effect on indicators of viraemia - the extent (P=0.0006) and duration (P=<0.0001) of virus excretion and the total amount of virus excreted (AUC, P=0.0006). Vaccination also had a significant effect (P=0.0017) on whether a horse was positive or negative for virus excretion during the study. Further research is needed to fully understand the specific properties of this vaccine that may contribute to its cross-protective capacity.

• Authors: H G W Pouwels, S M A Van de Zande, L J I Horspool, M J H Hoeijmakers
• Journal: The Veterinary record (Vet Rec) Vol. 174 Issue 25 Pg. 633 (Jun 21 2014) ISSN: 2042-7670 [Electronic] England
• PMID: 24795071 (Publication Type: Journal Article, Randomized Controlled Trial)
• Copyright: British Veterinary Association.

Chemical References

• Antibodies, Viral
• Influenza Vaccines
• Tetanus Toxoid
• Vaccines, Combined

Topics

• Animals
• Antibodies, Viral (blood)
• Horse Diseases (immunology, prevention & control)
• Horses
• Immunization Schedule
• Influenza A Virus, H3N8 Subtype (immunology)
• Influenza A Virus, H7N7 Subtype (immunology)
• Influenza Vaccines (immunology)
• Orthomyxoviridae Infections (immunology, prevention & control, veterinary)
• Tetanus Toxoid (immunology)
• Time Factors
• Vaccination (veterinary)
• Vaccines, Combined (immunology)