Two vaccines tested in France against avian flu have proven to be "very effective" in protecting mule ducks, raised for foie gras, from the virus, the health agency Anses told AFP on Thursday, paving the way for a national vaccination. within a few months. The “favorable results provide sufficient guarantees to launch a vaccination campaign from the fall of 2023”, for its part wrote the Ministry of Agriculture on its website.
The repetition and scale of the crises linked to avian flu (more than 20 million poultry slaughtered in 2021-2022 in France, already more than six million in 2022-23) have convinced European countries to imagine a vaccine strategy. In France, an experiment was launched last year around two candidate vaccines for waterfowl, developed by the Boehringer Ingelheim and Ceva Santé Animale laboratories.
European neighbors are testing vaccines in other poultry species. The French experiment involved a few hundred ducks, vaccinated or not, and euthanized at the end of the process. The virus currently circulating in France and around the world was inoculated into some of the ducks, previously vaccinated, to measure how much virus they excreted, and if they could still contaminate their congeners.
"Vaccination has made it possible to have very little excretion of the virus in inoculated animals", whether by the respiratory and digestive tracts, summarized to AFP Béatrice Grasland, head of the ANSES national reference laboratory for Ploufragan-Plouzané-Niort avian influenza. The two vaccines, with “very similar” results, also almost stopped direct transmission and “abolished” indirect transmission, by air.
"It's very effective," summarized Me Grasland, noting a very good level of protection "for vaccinated ducks" even in direct contact, in the same park, with the droppings of infected ducks. After a lull of a month and a half, the virus has been spreading again since the beginning of May in dozens of farms in the South-West, in particular in the Gers.
France plans to vaccinate ducks as a priority (mulard type but also Peking and Barbary - the latter being rather raised for their meat) because of their "particular role" in the dynamics of the epizootic. Ducks are very susceptible to the virus and excrete it into the environment even before showing symptoms, which contributes to the low noise spread of avian flu.