by Kelsey Piper
November 3, 2022
Extract:
Read more here: https://www.vox.com/future-perfect/202 ... s-vaccine(Vox) You probably don’t think about tuberculosis much. Growing up, I only read about it in history books, where it was often referred to as consumption and where it shortened the lives of such famous people as the poet John Keats, the playwright Anton Chekhov, and all the Brontë siblings. It’s a bacterial disease that lives mostly in the lungs, though if untreated it can spread throughout the body.
…
One thing that would make a huge difference for the fight against tuberculosis would be a better infant vaccine — and there are some candidates in the works. Recently, I heard from 1Day Africa, the African division of the nonprofit 1DaySooner, which works toward developing vaccines faster and ensuring everyone in the world can access them, about efforts in Malawi to get a human challenge trial of a promising new TB vaccine underway.
The logic of human challenge trials goes like this: Normally, vaccines are tested by vaccinating lots of people, and then waiting until some of them naturally get exposed to the disease. But that can mean the trials last for years, with millions of people dying in the meantime. For some vaccines, then, it makes more sense to test directly: A few weeks after volunteers are vaccinated, they are exposed to the infectious disease and monitored to see if they get sick (and make sure they get the medical treatments needed to recover if they do).
Challenge trials have been used for diseases like malaria and cholera. But they aren’t usually conducted for tuberculosis, partly because the long latency and long required course of treatment for the disease make such trials tricky. In particular, it’s hard to know for sure that a case of tuberculosis is gone and therefore hard to know that there’s no risk of innocent people being infected.
For years, though, tuberculosis researchers have been arguing that the human challenge model could significantly accelerate research on and development of a better TB vaccine. “The alternatives to a human challenge trial are very very expensive,” Josh Morrison, president of 1Day Sooner, told me. And since the people affected by TB are mostly poor, the unfathomable sums of money needed aren’t likely to be put up by pharmaceutical companies or rich-country governments.
