Here you can find the latest bTB Vaccination Update at the time this article was published.
The latest 8 updates are:
1: The vaccination of bovines against bTB can be carried out by the Cattle BCG vaccine. This is the same vaccine that is used to protect humans and badgers from TB. Recent studies in Ethiopia have shown that this vaccine not only protects vaccinated cattle directly, but it also reduces transmission between cattle by almost 90%. If vaccinated animals become infected, they are substantially less infectious to others. In the Ethiopian trial, cBCG vaccination was associated with a reduction in susceptibility to M.bovis infection of approx. 60% (95% CI, 34-73%) and with reduction in infectiousness of approx. 75% ( 95% CI, 45-98%) leading to a total efficacy of 89% (95% CI 64-99%).
2: Vaccination with BCG vaccine, does however sensitise cattle to Bovine Tuberculin PPD and compromises the specificity of the single intradermal comparative cervical test (SICCT) test which we use in the UK(so lots more false positives).
3: To address this, a DIVA test (differentiates infected among vaccinated animals) has been developed to identify cattle that have been infected with M. bovis in vaccinated herds. This DIVA test is also referred to as the DST-F test. A summary of the DIVA data generated to date at APHA has demonstrated promising results. The DIVA has been shown to be effective in detecting infected animals while giving negative results in vaccinated uninfected cattle. Separate field trials and experimental studies are currently ongoing to obtain more precise estimates of both the specificity and sensitivity of the DIVA, respectively, in both vaccinated and unvaccinated cattle.
4: What is known about the vaccine so far;
- CattleBCG is injected under the skin in cattle
- Animals will likely need annual revaccination
- Vaccinated animals must be tested with the DIVA skin test instead of the routinely used tuberculin-based skin test(SICCT)
The DIVA skin test principle and procedure is very similar to the SICCT test. However simultaneous injection of avian tuberculin for comparison is not required.
5: As previously stated, field trials have been underway in the UK since 2021 to understand both the safety and efficacy of the cBCG vaccine and DIVA test. DEFRA has just announced a third phase of field trials for the DIVA skin test. Deployment relies on the success of these field trials, especially with regards to the DIVA test.
6: There is still a lot of work to do before the vaccine and test can be rolled out. Both the vaccine and DIVA test have to achieve Marketing Authorisations from the VMD. International recognition of the use of the vaccine and DIVA test will have to be gained from organisations like the World Organisation for Animal Health (WOAH) and the EU so that our trade in animal and animal products is not affected. An IT system needs to be developed to record and trace vaccinates and crucially there needs to be acceptance of vaccination from across the range of industry stakeholders. To this end an industry:government TB vaccination core group was set up and has been designing deployment policy proposals for England and Wales. ID had a board member on this core group. After further consultation with groups across affected sectors it was planned to put the final proposals out for consultation during 2024(the election may have delayed this).
7: Vaccinating cattle against bTB will be a valuable addition to the bTB control toolbox but will not replace existing measures. Maintaining biosecurity measures on farm, avoiding risky trading and complying with testing protocols remain as important as ever in the fight against TB. Cattle TB vaccination is no magic bullet.
8: How close are we to be able to use the cBCG vaccine and DIVA test? To quote Professor James Wood on the recent BCVA webinar on TB vaccination(for details see below) “ I would be really disappointed if it wasn’t being used in 5 years time, not necessarily in a widespread area, but at least in some form in the higher incidence areas of England and Wales”.
BCVA Webinar; RBCG Vaccination in Cattle – a substantial reduction in natural transmission between cattle – 21.5.2024
