The first jab was given: 1800 day-old chicks received a vaccination against highly pathogenic H5N1 bird flu. Never before have chickens in the Netherlands been vaccinated against bird flu in a field trial. This marks the start of this field trial, which is taking place on behalf of the Ministry of Agriculture, Nature and Food Quality (LNV). It is an important step toward large-scale vaccination of poultry against the bird flu virus.
Minister Adema of LNV: "Avian flu is a serious disease that has affected the poultry sector enormously, it affects both the animals and the farmers, and of course many wild birds have also died because of it. We are therefore taking action together to reduce the number of infections in poultry."
Field trial vaccine against bird flu
Previous research in the laboratory at Wageningen Bioveterinary Research (WBVR) has shown that two vector vaccines against highly pathogenic avian influenza are effective against spreading the virus. The ministry is now having Wageningen University & Research (WUR), Royal GD (Animal Health Service) and Faculty of Veterinary Medicine at Utrecht University investigate whether these two vaccines are also effective at poultry farms.
At the start of the field trial, chicks are divided into several test groups. At regular intervals, a number of chickens from the field trial will be tested in the laboratory, under controlled conditions, to investigate the effectiveness against infection. During the trial the chickens are intensively monitored and controlled, in line with the new European regulation. This field trial is a scientific study and the products of the vaccinated chickens will not be marketed. Chickens are already being vaccinated against various diseases.
Results effectiveness vaccine
The trial on the two farms will last until the third quarter of 2025. First results are expected in the second quarter of 2024. Under field conditions, the effectiveness of a vaccine may differ from controlled conditions in a laboratory. For example, at a poultry farm, the housing and barn climate are different, the animals are vaccinated against more diseases, and there are other germs present in that could influence the effectiveness of a vaccine. It is important that the vaccines not only provide protection against disease symptoms, but mainly prevent the spread of the bird flu virus.
Bird flu poultry vaccination approach
The Dutch government wants to enable vaccination responsibly, with animal and public health and animal welfare in mind. Therefore, a step-by-step approach was chosen. In addition to the field trial, a pilot will be conducted to vaccinate a larger number of poultry farms in the Netherlands. The pilot is expected to take place on several poultry farms in the second quarter of 2024. The condition is that the vaccine has European approval by then and that the results of the first laboratory test are known.
The pilot will also pay close attention to the effects of vaccination on poultry trade and the establishment of a surveillance programme. That surveillance programme is to detect any infection on a vaccinated farm, something that might happen despite vaccination, as soon as possible. This will minimise the chance that virus will still continue to circulate.
Alertness among poultry farmers
It's still very important that poultry farmers stay alert and that they report a suspicion of bird flu to the Netherlands Food and Consumer Product Safety Authority (NVWA) as soon as possible, as they do now, and continue to apply the mandatory hygiene measures. This is currently the best way to minimise the risk of bird flu infection.
