A £1m field trial of a vaccine to combat tuberculosis in badgers has been launched by the government.
Badgers are blamed for the spread of TB among cattle herds
Badgers can carry bovine tuberculosis which they catch from cattle and other badgers before spreading it to herds.
Last year 24,000 cows infected with TB were put down and the cost of compensating farmers and testing for the disease was £92m.
The trials in Gloucestershire could lead to more than 100,000 badgers being vaccinated nationwide.
The Central Science Laboratory trials involve catching about 250 badgers in baited traps in the county where the disease is a major problem.
The animals will be taken back to the laboratory where they will be injected with the vaccine before being returned to their home set.
The initial stages of the trial aim to find out if the vaccine is safe for badgers and humans and whether it is effective against the disease.
It will take at least five years before the vaccine could be administered to the general badger population outside the lab through microcapsules mixed with peanuts.
Dr Chris Cheeseman, who is leading the project, said: "If vaccination of badgers worked you would save the lives of badgers, you would save the disruptive effect of culling, and it would save cattle and taxpayers' money, which is the fundamental problem."
Farmers, who cannot interfere with sets on their land because badgers are protected by law, have called on the government for a cull of the animals to protect their herds.
"The only prospect of culling really working is if it was carried out on a wide scale using methods that would kill every last badger from coast to coast," said Dr Cheeseman.
The National Farmers' Union says it supports the idea of vaccines but that culling is needed in the mean time.
"Until we do have adequate vaccines we need a culling programme aimed at addressing the disease in badgers to reduce the likelihood of their passing it on to cattle," said the NFU's TB adviser Alex Dinsdale.
"We are not targeting badgers, we are targeting the disease. Ultimately want to see healthy badgers and healthy cattle."
New cases of TB in cattle are rising at a rate of between 10% and 20% a year.
Earlier this year MPs on the Environment, Food and Rural Affairs Select Committee criticised a government consultation project on a badger cull for considering a targeted approach when scientific evidence showed only extensive action would cut TB levels in cattle.