Effectiveness of badger TB programme
The Food and Environment Research Agency (Fera) has spoken of the knowledge gaps surrounding the effectiveness of badger vaccinations for bovine tuberculosis (bTB).
Gavin Wilson, of Fera, told the Environment, Food and Rural Affairs Committee (EFRACom) that it is still unknown what impact a nationwide badger vaccination programme would have on TB in cattle.
Last year, around 2,500 baggers were vaccinated against bTB in Gloucester – an area too small to indicate the impact on a nationwide scale, according to Dr Wilson.
He said: "The test area in Gloucestershire is not large enough in its own right to look at cattle herd breakdown rates.
"The size of the trial means it will be more difficult to fill the knowledge gap, which is to find out what effect badger vaccination has on the rates of bTB in cattle."
Uncertainty also remains over the number of badgers in England and Wales. The most recent badger population survey was conducted in the 90s, with another not due to be completed until mid-summer.
A further project is set to take place this winter, funded by the Department for Environment, Food and Rural Affairs (Defra), to find the average size of badger social groups and the variability of family groups.
"These two surveys will give a clearer idea of badger populations in England and Wales," added Dr Wilson.
Furthermore, Fera Senior Scientist Steve Carter highlighted that we are still unaware of the number of badgers needed to be vaccinated in order to achieve herd immunity.
"[Herd immunity] would depend on a wide range of factors – for example, the prevalence of infection in the population, badger density and other environmental factors."
Over the past 10 years, bTB has cost the UK economy an estimated £500 million.
Defra is currently investing in research for an oral vaccine, which is expected to be cheaper to deploy – a necessity if the nationwide programme is to go ahead.
The latest 
