Noting that vaccinations could hide and spread the deadly disease, Britain's farm ministry, in its almost simultaneous statement, said that vaccinating poultry could mask the effects of the disease and make it more difficult to tackle its spread among the poultry population.
"Crucially, though these vaccines protect against disease, they will not prevent birds from becoming infected and shedding virus," Deputy Chief Vet Fred Landeg said in a statement issued by the ministry. "Because symptoms of disease would be masked, the hidden presence of disease would pose a serious problem."
Independent scientists in Britain, where there are no confirmed occurrences of H5N1, have raised similar concerns about bird flu vaccinations this week. Britain's organic certification body, the Soil Association, has backed limited, targeted vaccinations but added it was not convinced the French and Dutch mass vaccination policies would be the best strategy.
Landeg observed that previous outbreaks of bird flu had been successfully eliminated by early detection, the slaughter of infected birds and the introduction of movement controls.
"However, we of course keep our policy under review as the vaccine manufacturers continue to develop their products," Landeg added.
On the continent, France and the Netherlands today secured approval to vaccinate millions of poultry against bird flu in the European Union's first preventive vaccination plans.
However, the vaccination will be limited in scope, with the panel of EU veterinary experts also stipulating that vaccinated poultry will have to be kept separate from other birds.
The decision came as Austria today reported the possible presence of the disease in some ducks and chickens held in an animal shelter in Graz.
France and the Netherlands, which have the EU's largest poultry sectors, are targeting different sectors of their bird population for vaccination. The French are initially hoping to vaccinate about 900,000 birds and will carry out the vaccination of ducks and geese in three high-risk risk areas, including the Landes region that is a leading producer of foie gras.
France's main farm union said that poultry consumption had dropped in the past week and was down 20-30% from the previous year, following the discovery of an infected wild duck near Lyons.
The Dutch are focusing their efforts on the country's 5 million free-range laying hens and privately owned poultry. The Dutch are trying to balance their eagerness to avoid a repeat of the 2003 bird flu crisis, which forced a mass culling of the country's flock, with concerns that the Dutch poultry trade could be hurt if other countries refused to allow imports of poultry from vaccinated birds.
European Union health ministers were expected to meet tomorrow in Vienna to coordinate their response to bird flu, which has already been found in wild birds in seven EU countries, namely Greece, Italy, France, Austria, Germany, Hungary and Slovenia.