Overview: Malaria is one of humanity’s oldest and most devastating plagues. In many parts of the world, it remains an ever-present scourge that sickens or kills millions of people each year. What if it could finally be defeated? Now, scientists may be on the verge of a breakthrough with a promising vaccine in the final stages of testing and approval. Follow researchers on a quest to deliver humankind from one of the world’s deadliest diseases.