A malaria vaccine – dubbed "RTS,S," the first in the world – is headed to Ghana, Kenya and Malawi next year as part of a World Health Organization pilot program. It has the potential to save tens of thousands of lives in Africa.

How it works: Young children must get a total of four vaccines – three in three months, spaced a month apart, followed by another shot after a year and a half. This pilot program is intended to help researchers determine if they could launch a full-scale malaria vaccine program, since a complete, real-world picture of the vaccine's safety and effectiveness is still developing outside the realm of a clinical trial.

Approximately 375,000 kids between ages 5 to 17 months will receive the vaccine in the pilot program. There's evidence that all four doses block about 40 percent of malaria cases. For comparison's sake, that's "much lower than approved vaccines for other conditions," the BBC reports.

When studied, the vaccine also eliminated one-third of the most severe cases, not to mention limiting the need for blood transfusion or in-patient care for children. The fourth dose proved important, as the treatment benefits fell when not administered.

There were 212 million new cases of malaria in 2015, and 429,000 deaths, according to the World Health Organization. And every two minutes, a child died from the disease. The countries picked for the pilot already have malaria-fighting efforts going on (i.e. bed nets) but are nonetheless swamped by the disease. Those most vulnerable to malaria include children under age 5, babies and pregnant women.

Sub-Saharan Africa is home to 90 percent of the world's malaria cases, though insecticide-treated nets have helped stop about 69 percent of the cases. In 2015, approximately 43 percent of people at risk there didn't have nets or indoor insecticide spray as protection.

World Malaria Day is Tuesday, April 25.