Hookworm

For many, the idea of having a few dozen hookworms set up shop in your gut sounds more like a Survivor challenge than a beneficial health therapy, but scientists see a bright future in the human worm farm's ability to protect against chronic disease.

A clinical trial of a permanent vaccine developed by the US-based Sabin Vaccine Institute for hookworm has been completed in Brazil, giving hope for a permanent end to a problem that affects 600 million people worldwide.