Poultry stocks in the area of southern Hungary where three swans died from bird flu are clear of the virus, Hungarian Prime Minister Ferenc Gyurcsany said on Sunday, according to DPA. Gyurcsany, during a visit to a duck farm, said that vets had examined poultry stocks in the settlements of Nagybaracska and Csatalja, and found them healthy. Hungary has been developing a vaccine against the bird flu, which is due to begin production by the end of March. Gyurcsany earlier said that if the disease were to spread to Hungary's poultry industry, the vaccine would be administered to those who worked directly with the birds. The H5 virus was confirmed in Hungary last Wednesday, and although the presence of the deadly N1 subtype is not certain, the director of Hungary's National Animal Health Institute said it was "very likely." Official confirmation will come from samples being examined by the European Union in a laboratory in Weybridge, Britain. Hungary has set up a protective cordon around the area where the birds were found, and dead birds found elsewhere in the country - including a flock of swans in the north - have all tested negative for bird flu.