Two vaccines have proven successful in protecting chickens against bird flu. Research by Wageningen Bioveterinary Research (WBVR) shows that two ‘vector vaccines’ “significantly reduce the number of infections”.
In a lab situation, the vaccines protect the chickens against bird flu and prevent the spread of the virus. This summer, one or two poultry farms will be experimenting with the vaccines, says Agriculture Minister Piet Adema. As far as is known, the vaccines only work for chickens and turkeys.
Adema emphasizes that a controlled trial is different from a field trial, in which the vaccine is applied in practice. The trial, which will start this summer, will “take more than a year, among other things to get an idea of how long the chickens are still immune after vaccination”.
The minister hopes to receive the first results on effectiveness before the end of the year. “Data on duration of immunity will become available in 2024 and 2025.”
The University of Wageningen researched a total of four possible vaccines. Each vaccine was given to ten chickens. After that, five chickens were deliberately infected with bird flu, the other five chickens were not infected. They were then placed together in a stable.
In two vaccines, the infected chickens did not get sick and did not transmit the virus to the non-infected chickens. These are so-called HVT-H5 vaccines. These were developed by the French Ceva Santé Animale, which also has a branch in Naaldwijk, and the German Boehringer Ingelheim Animal Health.
The tested vaccines have not yet been registered in the European Union and can therefore not yet be used in agriculture. Wageningen does speak of “an important first step towards vaccination against the bird flu virus in poultry farming”. Further tests should clarify whether the vaccines work in practice, how long they protect and whether the chickens may need a booster shot later on.
The two other vaccines, which seem to work less well, were made by the Bulgarian Huvepharma and the American MSD.
NOS spoke to Nancy Beerens of Wageningen University & Research about the vaccines: