Two vaccines tested in France have proved "very effective" in protecting ducks from bird flu, ANSES and the Ministry of Agriculture reported Thursday, paving the way for a national vaccination while the virus does not leave respite to farmers. After a lull of a month and a half, the virus has begun to flare up again since early May in the Southwest, contaminating more than 70 farms, especially in the Gers.
The repetition and scale of crises related to avian influenza (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.
The French experiment involved thousands of ducks
In France, an experiment was launched last year, around two vaccine candidates developed by Boehringer Ingelheim and Ceva Santé Animale. They aim to protect Mulard ducks, bred for foie gras, from the virus. European neighbours are testing vaccines in other poultry species. The French experiment involved a few thousand ducks, vaccinated or not. They were euthanized at the end of the process.
The "favorable results provide sufficient guarantees to launch a vaccination campaign as early as autumn 2023," the Ministry of Agriculture wrote on its website. The virus circulating in France and around the world was inoculated into a fraction of the ducks, previously vaccinated, to measure how well they excreted the virus, and whether they could still contaminate their congeners.
"It's very effective"
"Vaccination has made it possible to have very little shedding of the virus in inoculated animals," whether by respiratory or digestive tract, summarized to AFP Béatrice Grasland, head of ANSES's national reference laboratory for avian influenza Ploufragan-Plouzané-Niort.
The two vaccines, with "very similar" results, have also "almost stopped direct transmission" - when animals are in close contact - and "abolished" indirect transmission, by air, that is to say potentially from one barn to another.
See alsoEurope is experiencing the avian flu "the most devastating" in its history, according to health authorities
When animals were not vaccinated, "an inoculated animal infected another animal every two hours," she said. Conversely, those who were vaccinated were "almost not" contaminated by their neighbor "even in direct contact, in the same park, with the droppings" infected. "It's very effective," Grasland summarized, noting that under these conditions, "normally the epidemic does not start."