World TB Day, observed every year on 24 March, is a moment to reflect on the global effort to combat tuberculosis, not just in humans, but in animals too. Bovine tuberculosis (bTB) remains one of the most significant animal health challenges we face in the United Kingdom (UK) today. Here at APHA, we are proud to mark this occasion by sharing an exciting update on the progress of Phase 3 of the cattle TB vaccine field trials.
Why does bovine TB matter?bTB costs the taxpayer over one hundred million pounds a year, and farmers in lost income and extra business expenses. The human and economic toll on farming families and rural communities is profound, which is why the development of a deployable cattle vaccine has never been more important for the UK and other countries dealing with the disease.
The journey so farSince 2021, APHA has been conducting field trials of the BCG vaccine alongside its companion Detect Infected amongst Vaccinated Animals (DIVA) skin test. The DIVA skin test is a crucial innovation as it allows us to distinguish between cattle that are vaccinated and those that are infected with the disease, something the current tuberculin test cannot do.
Phase 1, completed in May 2022, assessed the safety and specificity of the DIVA skin test in unvaccinated animals. Phase 2, completed in November 2023, then assessed the safety of the BCG vaccine and the safety and specificity of the DIVA skin test in vaccinated cattle. Both phases successfully demonstrated that the vaccine and skin tests are safe to use.
Phase 3: where we are nowWe are delighted to share that real progress is being made in Phase 3 which is being delivered by APHA, on behalf of Defra, Welsh Government and Scottish Government. APHA are conducting all on-farm activity directly, a mark of our deep commitment to seeing this work through to completion.
Phase 3 began on a farm in Wales, and we now have 11 farms participating across England and Wales, to reach a minimum of 700 animals. This phase is designed to gather additional data on the performance of the companion DIVA skin test in a larger number of BCG vaccinated animals, and to explore options to optimise its use, further informing how the vaccine can be deployed most effectively to support eradication strategies across Great Britain (GB). We are pleased to report that six of the 11 enrolled farms have now completed all on-farm activities, which includes the administration of BCG vaccinations followed by the DIVA skin test. This is a significant milestone and a testament to the hard work of APHA staff and the farmers involved. On-farm activity across the remaining farms is expected to be completed by summer 2026.
APHA staff visiting a farm in the field trial Ministerial visit to the trialsThe importance of this work was highlighted earlier this month when we welcomed Dame Angela Eagle, Defra Minister for Food Security and Rural Affairs, to one of the farms taking part in the field trials.
Minister Eagle joined APHA staff for a tour of the farm and observed the BCG vaccine being administered to cattle, gaining a first-hand view of the trial process. She also took the opportunity to engage directly with the APHA staff, and the farmer involved in delivering this critical phase of the programme - a visit that reinforces the government commitment to achieving a deployable cattle TB vaccine.
Dame Angela Eagle, Defra Minister for Food Security and Rural Affairs, pictured centre What comes next?The completion of Phase 3 will mark the end of the field trials for the bTB vaccine. If successful, it is hoped that the combined vaccine and test could be rolled out within the next few years, which could potentially bring closer the goal of eradicating bTB by 2038 in England and by 2041 in Wales.
A collective effortNone of this would be possible without the dedication of the farmers who have opened their farms to this research, the veterinary professionals supporting the trials on the ground, and the APHA scientists and field staff who have worked tirelessly for more than 20 years on research to reach this point.
On World TB Day, we want to say a sincere thank you to everyone who has played a part in this journey. The road to a deployable cattle TB vaccine has been long, but the progress made in Phase 3 gives us every reason to be optimistic.
To find out more about the bTB cattle vaccination programme, visit the TB Hub.
seen at 15:14, 24 March in APHA Science Blog.