Government vets have dismissed the idea of vaccination as a way of controlling avian flu, describing it as “too limited to provide a general solution”.
“Though these vaccines protect against the disease, they will not prevent birds from becoming infected and shedding virus,” said deputy chief veterinary officer at DEFRA, Fred Landeg.
“Because the symptoms of the disease would be masked, the hidden presence of the disease would pose a serious problem.
“The vaccines also have severe practical limitations in that they need to be delivered by individually injecting each bird,” he added.
“It can take up to three weeks to develop immunity, and some poultry require two doses.”
Mr Landeg’s comments came at the same time as Brussels gave the go-ahead for French and Dutch poultry producers to start vaccinating their birds against H5N1 avian flu in a limited programme.
The decision was taken by veterinary experts on Wednesday (22 February) following two days of intense debate into the pros and cons of vaccination.
EU food safety commissioner Markos Kyprianou said it was essential to explore every possible option to protect poultry.
“Targeted vaccination, accompanied by sufficient guarantees, can be an effective tool when coupled with rigorous preventive measures.”
Following the decision, France has already started vaccinating up to 900,000 ducks and geese in the Landes, Loire-Atlantique and Vende departements.
These areas are deemed most at risk from H5N1, and the French maintain that it is impractical to keep these birds indoors.
The Dutch plan applies to hobby farmers and to free-range laying hens throughout the whole country.
There are about seven million such birds, and vaccination will be on a voluntary basis as an alternative to housing.
In both cases, great emphasis is being put on rigorous follow up controls, including movement restrictions on vaccinated flocks and strict monitoring to check there is no undetected outbreak of avian flu.
Live birds from vaccinated flocks may only move to other vaccinated flocks or direct to slaughterhouses.
Meat and eggs may be marketed within the EU or exported to third countries.
The NFU says it is open-minded about vaccination, though it could present huge logistical problems.
The Soil Association, however, has urged the use of ring-vaccination to create a firewall around any outbreak of avian flu in the UK.
Director Patrick Holden called for DEFRA to build up stocks of vaccine now, before H5N1 reaches these shores.
Despite fresh outbreaks of avian flu in wild birds throughout Europe this week, DEFRA is still maintaining there is no need to house all poultry in the UK.