Farmers have dismissed claims that a vaccine against bovine TB could be rolled out within months, negating any need to cull badgers to stop the disease.
They say the claims of a major breakthrough in combating bovine TB are not realistic in time-scale – and that a vaccine is far from totally reliable.
While a test to differentiate between beef from infected cattle and cattle that have been vaccinated is being developed, it may take a very long time to be accepted throughout the EU, making exports of vaccinated beef impossible.
With controversial culls of badgers likely to begin within a few weeks in two TB hotspot areas in the South West, the development of the differentiation test is "absolutely critical" according to the Government's chief veterinary officer Nigel Gibbens.
"We believe we have one that can be practically applied, but in terms of getting international recognition for it, it is months and possibly years away," he said.
The differentiation test, and TB vaccine for use in cattle, would have to be validated and EU law changed before beef from vaccinated cattle was available for consumption in Europe. In excess of £34 million has already been spent on research, and a further £15 million is earmarked for development of vaccines for cattle and badgers over the next four years. The process of approving any test to differentiate TB-infected from vaccinated cows is likely to take many years, said the National Farmers' Union (NFU).
Andrew Butler, the NFU acting regional director in the South West, said the EU would want assurances that the vaccine and the test were safe and effective. He said: "During this time the problem of TB will get worse, with more badgers and cattle getting the disease.
"Even if it were eventually approved, the cattle vaccine is not 100% effective – so there will be a significant percentage of cattle which are not immune. As it's against the law to use the vaccine in the field in Europe there is no reliable data, but small-scale trials in South America showed it was only between 56 and 68% effective in cattle – and if badgers are still infected then the disease will continue to spread."
Mr Butler stressed the NFU continued to support the Government's science-led TB eradication policy, which includes badger controls, as well as tighter cattle controls and badger vaccination, because at this stage it was the only way forward.
He added: "Evidence from other countries shows us that vaccination alone does not work while there is a third party host harbouring the disease, and diseased animals remain in the wild unchecked."
Licences have been granted for pilot culls over six-week periods in West Somerset and around Tewkesbury in Gloucestershire, when 70% of badgers in those areas will be shot by trained riflemen.