Immune cells increased by TB vaccine, study finds
NK immune cells increased within just two days of vaccination.
A study has confirmed how a tuberculosis vaccine stimulates key immune cells to encourage infection resistance.
The Bacille Calmette Guerin (BCG) vaccine prompted the production of natural killer (NK) cells in cattle, which are associated with infection response.
Research, conducted by scientists from the Roslin Institute, saw researchers observe the effects of BCG on calves which had been previously vaccinated, as well as those receiving BCG for the first time. These results were compared to those of unvaccinated animals.
Tissue samples, taken from lymph nodes in each cow’s shoulder, revealed a rise in NK cell numbers just a day or two after vaccination. This was true for cows receiving the vaccine for the first time, as well as those receiving a repeat dose.
Researchers looked for any sign that the different types of immune cells were interacting as a result of the BCG vaccine. This included changes in NK cell location, clustering, or aggregation.
While the researchers did not find any of these interactions, further research will examine if there were any changes to the function of the cells.
The study has given researchers a fresh understanding of the processes behind effective BCG vaccination. It is hoped that new insights could lead to more refined and effective vaccines against bovine tuberculosis.
As well as explaining the key biological processes behind the BCG vaccine, the findings will enable researcher opportunity to make TB vaccination more efficient and supportive of animal health.
Future studies will see researchers examine the spatial distribution of various immune cell types. This could further detail the process driving protection to the disease.
Jayne Hope, from The Roslin Institute, said: “BCG is known to be an effective vaccine in people and animals – despite this, there are some gaps in our understanding of how it works.
“Unravelling the mechanisms by which BCG impacts immune cells – including NK cells, which are thought to have a central role in vaccine-induced immunity – could support improved vaccine design to benefit animals and people, for example by identifying methods to stimulate enhanced protective immunity following vaccination.”
The full study can be found in the journal Discovery Immunology.
Image © Clint Austin/Shutterstock.com
Veterinary practices are being urged to help owners safely dispose of any unused and expired pet medicines - not just antibiotics - during November's Animal Medicines Amnesty. 
