For the active immunisation of horses and ponies to reduce clinical signs of respiratory disease and viral shedding caused by equine influenza viruses of H7N7 and H3N8 types (European and American strains) as demonstrated by serology and challenge infection using the A/equi-2/Sussex 89 and A/equi-2/South Africa/4/03 strains.

Protective antibody titres against the listed equine influenza virus strains have been shown to be present within two weeks of completion of the second dose of the primary vaccination course and protection has been demonstrated against challenge with virulent isolates of the listed equine influenza virus strains.

Following administration of the second dose of the primary vaccination course, protective antibody titres against the listed equine influenza strains last at least 6 months. After completion of the 3 dose primary vaccination course and for subsequent booster vaccinations, protective antibody titres against the listed equine influenza strains last at least 1 year.