Every year on March 24, we commemorate that tuberculosis, TB for short, continues to claim many victims. Far too much, because the WHO estimates that there are approximately 10 million new infections and approximately 1.5 million deaths each year. That's over 4,000 deaths a day!
Worldwide, almost a quarter of the world's population is a carrier of the TB bacteria. At some point, these people can become ill if their health is weakened by, for example, malnutrition, diabetes or co-infection with a virus. And everytime a person falls ill, TB has the opportunity to spread further.
Only with relentless research and development it will be possible to better understand TB and develop better remedies. The development of a more effective vaccine for TB prevention is the best option to break the spreading cycle.
Limited success, or more?
A vaccine against TB has been around for almost 100 years. That vaccine is called BCG, an abbreviation of the name after its French discoverers, Bacillus Calmette & Guérin. In countries where TB is common, BCG is often administered after birth. This saves more than a hundred thousand children's lives every year from mortality. But unfortunately, as shown in the numbers above, this protection is too small to get TB out of the world.
A remarkable fact is that health data shows that BCG not only helps against TB, but also reduces the mortality rate in young children due to other respiratory infections. Thanks to fundamental scientific research, we now think we understand how this works.
BCG is a living, weakened bacterium that no longer makes people sick, but which stimulates the host's immunity in a broad sense. This stimulated or trained immune system also makes it easier for someone who receives the BCG vaccine to fight other infections. In particular, thanks to research in laboratory animals, evidence has been provided for the claim that BCG can provide so-called ‘non-specific cross protection’.
The TB vaccine in the fight against the current corona epidemic
Based on the training effect of BCG on the immune system, researchers in the Netherlands announced last week to use this TB vaccine in corona risk groups. They will investigate whether BCG can curb coronavirus infection. As long as no specific corona vaccine is available, this opportunity is hopeful that we can do something about this fast-moving epidemic.
At BPRC we have recently been able to determine the general immune training, by live weakened TB vaccines, including BCG, in rhesus macaques. This reinforces our understanding and the predictive value of our research into the immune system, and also the efficacy of new (preventive) therapies for humans. Because rhesus macaques are also susceptible to coronavirus infection, BPRC is currently exploring opportunities to strengthen the clinical BCG corona initiative.
COVID-19: a message of solidarity
By TuBerculosis Vaccin Initiative (TBVI)