Vaccine against tuberculosis
Fighting tuberculosis bacterium as a virus
Tuberculosis (TB) is the deadliest infectious disease in the world. TB is showing increasing resistance to antibiotics and in a number of countries almost no effective medicine is available. The whole world will have a problem if we lose the last line of defence, which is why senior researcher Ad Koets from Wageningen University & Research (WUR) believes it is time for a new approach.
WHY THIS RESEARCH?
The TB bacterium is becoming increasingly resistant to antibiotics, so new breakthroughs are needed to fight this disease.
The way in which TB bacteria develop in the human body resembles the way in which viruses work. Looking at the disease from that perspective helps us work on a possible vaccine.
“The final goal of our project is to find a vaccine against TB,” Koets says. “We want to do this by approaching the disease more as a virus than as a bacterial infection. That might sound strange but, just like Q-fever and chlamydia, TB has a specific feature: the bacteria enter human cells and transform them into a biotope where they can multiply. In this regard, TB functions like a virus. So it is worth looking at the biology of the disease from that perspective and letting go of the traditional approach to bacterial infections – thinking not in terms of antibiotics but in terms of vaccines. Such a fresh perspective is an excellent example of how we at WUR try to look beyond existing paradigms.”
‘Not so much preventing infection, but limiting its spread’
In the first steps of the development of this vaccine, Koets and his team want to use previous research on the ‘Rift Valley fever’ virus. “A fellow researcher has developed a vaccine platform on the basis of that virus,” he explains. “This virus has adjusted itself to people and ruminants, which are the same target groups as those of TB bacteria.
Tuberculosis mainly affects the lungs. Photo: Shutterstock
The goal is to find a vaccine against tuberculosis. Photo: Shutterstock
“Adding certain elements of the TB bacterium to the Rift Valley fever virus enables it to be used as a transporter to bring a TB vaccine to the cells. We are already studying which elements of the bacterium we have to add. In the project that we would now like to start, we are going to work on a proof of concept: does this theory actually work in practice? Have we extracted the right elements from the bacterium? Can we successfully get them into the right places in the cells? And what will happen if we expose the cells to a TB infection? These are the questions that we now want to answer.”
DRASTICALLY REDUCE SPREAD FROM ONE PERSON TO ANOTHER
According to Koets, it is still impossible to say what the impact of such a vaccine would be. “At this stage, we cannot yet claim that we will be able to prevent the infection, but I am convinced that we can drastically reduce its spread from one person to another. A very large number of people carry the bacterium, but only ten per cent actually become ill. We are also trying to reduce the symptoms for that group.
“Taken together, this could all lead to the disease eventually being eradicated. And that, too, is part of our new way of looking at things: not so much trying to prevent the infection, but trying to limit its spread and impact. That is possible both because someone who has been vaccinated and who gets TB will infect fewer people and because, after they have been vaccinated, people will become infected less quickly. We would be heading to a world in which TB no longer forms a threat to anyone.”
DR AD KOETS
Researcher, Wageningen University & Research
Vaccines, Anatomy and morphology of animals, Breeding and genetics, Animal health and welfare, Immunology, Animal physiology and biochemistry, Bacteriology, Epidemiology, Genetics, Gene expression analysis, Host-parasite relations, Microbiology, Molecular biology, Molecular genetics, Veterinary medicine, Animal diseases, Zoonosis, Pathology
Photo: Gea Hogeveen