“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.”

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.”