Researchers are trying to find new proteins which can be used in a vaccine to trigger an immune response and provide long-term protection against Mycobacterium tuberculosis (MTB).
Bacillus Calmette-Guérin (BCG) is the only available vaccine but it is of limited effectiveness in protecting against tuberculosis (TB).
Professor Ajit Lalvani, from the National Heart and Lung Institute at Imperial College London who led the research said: “Despite most of the world’s population having had a BCG vaccination, there are still nine million new cases of TB every year, so we urgently need to develop a more effective vaccine for TB.”
The World Health Organization (WHO) estimates that one-third of the world’s population is infected with Mycobacterium tuberculosis, resulting in an estimated 8 million new cases of tuberculosis and nearly 2 million deaths each year.
Vaccines work by stimulating the immune system and the best candidates for vaccines are those that trigger the strongest response from the immune system.
In the new study, scientists identified a protein, called EspC, that triggers a stronger immune response in people infected with the TB bacterium.
This protein is secreted by the TB bacterium but not by the BCG vaccine. As a result, the BCG vaccine does not induce an immune response to this protein, so deploying it as a new TB vaccine would provide additive immunity over and above that provided by BCG.
“Despite most of the world’s population having had a BCG vaccination, there are still 9 million new cases of TB every year,” said senior author Professor Ajit Lalvani, from the National Heart and Lung Institute at Imperial College London. “So we urgently need to develop a more effective vaccine for TB.
EspC is an extremely promising candidate for a new TB vaccine that could stimulate broader and stronger immunity than BCG.