The next stage of field trials for a cattle vaccine against bTB and a skin test that allows officials to differentiate between infected and vaccinated animals have been announced today (27 February).

APHA wants farmers and vets to volunteer and support the delivery of the project, which will take place from 2026/7 on commercial cattle farms in areas of England and Wales where there is a low incidence of bTB.

There have already been two phases of the trials, with the second phase – completed in March 2024 – enabling government to collect safety data for inclusion in any upcoming marketing authorisation applications.

Additional data

Phase three of the trials aims to gather additional data on the “detect infected among vaccinated animals” (DIVA) test specificity and explore options to optimise the performance of the new test.

This will involve assessing the companion DIVA skin test on a broader cohort of vaccinated animals, a key step as the lack of an effective DIVA test for bTB has historically been a significant stumbling block against deployment of the vaccine in cattle.

Defra claims it is working “at pace” on a revised TB eradication strategy in England and says its new strategy will mark a significant step-change in approach that will also consider a range of further measures, including boosting cattle testing.

Immune response

Laboratory studies have indicated that the vaccine and DIVA skin test are safe and that the test performs well, under controlled APHA facility environments.

The Bacillus Calmette–Guérin (BCG) vaccine has been used in humans since 1921 and has been proven to stimulate a protective immune response in vaccinated cattle too.

Previous studies with vaccinated animals have demonstrated significant protection against experimental challenge with high dose of bTB, a disease that the APHA estimates costs UK taxpayers around £100 million and a further £50 million to the industry every year.

Effective approach

UK CVO Christine Middlemiss said: “Bovine tuberculosis has remained one of the most difficult animal disease challenges to tackle, causing devastation to farmers and rural communities.

“These trials and the active participation of farmers will help us in ensuring any new vaccine and testing approach is both effective and practical.”

Those interested in taking part in the research project should contact the APHA by emailing [email protected]