A New Vaccine for TB

I found a number astounding, Norbert. How many of the world's people carry the Tuberculosis bacterium? I don't know' under ten percent? A quarter! Isn't that nuts? But people with latent tuberculosis or TB don't have symptoms or the disease and are not contagious. However, if they're not treated, the bacterium could activate.

Here's where a new vaccine could help. It can prevent up to half of people with latent TB from developing active disease. So, we're not talking about the BCG vaccine which prevents TB in children. This new vaccine is called M-seven-two/AS-zero-one-E and is a fusion of two proteins from M. tuberculosis plus an adjuvant which is a substance added to vaccines to help stimulate an immune response.

The study enrolled just over thirty-five hundred adults with inactive M. tuberculosis in Kenya, South Africa and Zambia. The goal was to determine if the vaccine could prevent latent infections from activating. The patients were randomly assigned to receive the two doses of the new vaccine or a placebo and were followed for three years after the second dose.

Twice as many of those who received the placebo developed active TB than those who received the vaccine. Even though the vaccine stimulated the immune system with one dose, the second dose boosted its response.

It's the first vaccine to show any protection for people already infected with the bacterium. That's tremendous because nearly one and a half million people die from TB each year.