A trial has begun into whether three potential bird flu vaccines could protect farmed animals from a disease that is now a year-round threat.

Wageningen Bioveterinary Research (WBVR) in Lelystad has been asked by the Dutch agriculture minister to conduct trials into vaccines for the H5 avian flu virus in laying hens. The first results from the three-month trial are expected in December.

Expert Nancy Beerens said that the virus, which typically arrived with migrating water birds from Siberia, has now spread to other breeds and is present in the summer months when it used to disappear.

‘Our summers used to be free of bird flu infections,’ she said in a press release. ‘This year we saw for the first time that the bird flu season did not end with the departure of migratory birds in April. The virus has been infecting birds that summer in our country, which means that poultry farms started the summer with bird flu.’

Largest cull

Despite culling more than four million birds, transport bans and orders to keep birds inside across the Netherlands since last October, each week new infections are discovered. On Monday, another 200,000 chicks were culled after bird flu was found on a poultry farm in Nieuw-Weerdinge in Drente – the largest single cull yet.

The virus affects farmed turkeys, chickens, ducks and geese and despite heightened biosecurity measures, experts and farmers believe only a vaccination – and new rules on European transport of vaccinated birds – can combat the deadly disease.

The first Dutch trials will take place in a high containment unit at the WBVR lab. ‘The new types of vaccine that we are testing in this study are expected to provide better protection against spread of the virus,’ added Beerens.

‘The results of [this and other European] studies are very important to get all EU member states on track for vaccination.’