Bovine tuberculosis (bTB) is an issue the Irish agricultural industry has been battling for several decades now and an outbreak in a herd can cause significant difficulties for the herds and herd owners that are impacted.

Total expenditure by the state on the bTB eradication programme for the year 2023 hit roughly €74.3 million – a significant jump of 29% from the €57.4 million figure in 2022.

The figure had been hovering in the mid-€50 million range for the past number of years.

While the amount of money spent by the state on the programme increased by approximately €17 million last year, the herd incidence rate also went up, reaching almost 5% by the close of 2023.

The challenges associated with the eradication of the disease are evident and many farmers often post the question if a vaccine could be used to control the incidents of bTB.

Agriland put the question to the Department of Agriculture , Food and the Marine (DAFM), asking if the use of vaccines has been considered under the bovine TB Eradication Programme and if the department would make a statement on the matter.

Responding to the query, DAFM said: “The main global body of research on developing a vaccine for tuberculosis in bovine animals is being carried out by the Department for Environment Food and Rural Affairs (Defra) in the UK.

“This department [DAFM] continues to engage with colleagues in Defra and is monitoring this very closely.

“To date the biggest issue with a vaccine for cattle has been the lack of availability of a test that is capable of distinguishing between an animal that is truly infected and one that has been vaccinated.

“The candidate vaccine, CattleBCG, a BCG strain, has shown in past studies to reduce TB severity in cattle. Whilst offering promise, it needs further testing however to determine its effectiveness in field conditions.”

The DAFM statement explained that even if the research surrounding the rollout of a vaccine for bTB is successful, “there are a significant number of legal and international trade obstacles to be surmounted before a vaccine for tuberculosis in bovine animals can be used as part of our bovine TB eradication programme”.

Bovine TB vaccine ‘at least 10 years from the market’

Last December, Agriland reported that senior superintending veterinary inspector at the DAFM, Dr. Damien Barrett said that “our understanding is that [the vaccine] is at least 10 years away from the market”.

Dr. Barrett told the Committee on Agriculture, Food and the Marine last year that colleagues in the UK are developing a vaccine which would enable the differentiation between an immune reaction due to vaccination as opposed to infection.

Safety trials of the vaccine, known as ‘Detecting Infected among Vaccinated Animals’ (DIVA), have “essentially been completed” and demonstrated that it does “no harm”, he told the committee.

In response to a question by Senator Paul Daly about whether the DAFM would be open to TB vaccines for cattle, provided they have received certification, Dr. Barrett said:

“We have very much an open mind to this. If and when it becomes available we will certainly be exploring this and it is certainly something that we would be interested in pursuing.

“The issue about a TB vaccine for bovines, he said, is that if the current vaccines were given to cattle, they would fail the tuberculin test which would have “huge implications” for exports.”

Raising potential issues in relation to certification for a product “as TB-free” once vaccinated, he said that support from the World Organisation for Animal Health (WOAH) will be needed.

The vaccine for cattle in the trials in the UK is the same given to humans and is “lifelong”, according to Dr. Barrett who added that “it is certainly lifelong for the badgers”.