Encouraging results on vaccination of ducks against avian influenza
Together with the Toulouse National Veterinary School, ANSES is co-publishing the results of two experiments carried out to test vaccines designed to protect ducks from highly pathogenic avian influenza (HPAI). The two vaccines gave similar results: they greatly limited direct transmission when the animals were in close contact, and also blocked indirect airborne transmission.
These experiments, organised under the governance of the Ministry of Agriculture and Food Sovereignty, were conducted by ANSES and the Toulouse National Veterinary School (ENVT) in partnership with the French interprofessional committee for fattened goose and duck production (CIFOG), local authorities and pharmaceutical companies.
The studies were carried out at experimental sites under actual field conditions, on the type of ducks used in France for foie gras production (mulard ducks), to ascertain the practical possibilities for implementation on farms. In addition to this field phase, the studies each included experiments carried out in the containment level A3 animal housing at the ANSES National Reference Laboratory for avian Influenza in Ploufragan (Côtes d'Armor).
The aim of the first experiment was to study the ability of vaccines to confer clinical protection and reduce viral shedding.
The second experiment sought to assess the reduction in viral transmission between vaccinated ducks.
The results of both studies confirmed the reduction in viral shedding in the animals, whether by the respiratory or digestive route. They also demonstrated control of direct HPAI transmission in vaccinated animals and the absence of any transmission via indirect contact, i.e. via airborne transmission, under the experimental conditions.
"These vaccines are highly effective. When it was not vaccinated, an inoculated animal infected another animal every two hours. Conversely, virtually none of the animals that had been vaccinated were contaminated by their neighbours, even if they came into direct contact with infected droppings in the same pen" explained Béatrice Grasland, from the ANSES National Reference Laboratory for avian influenza.
This work provided input for the HPAI vaccination action plan announced by the Ministry of Agriculture and Food Sovereignty on 25 May.