Malaria has been one of the biggest scourges on humanity for millennia and mostly kills babies and infants.
Having a vaccine - after more than a century of trying - is among medicine's greatest achievements.
The vaccine - called RTS,S - was proven effective six years ago.
Now, after the success of pilot immunisation programmes in Ghana, Kenya and Malawi, the World Health Organization says the vaccine should be rolled out across sub-Saharan Africa and in other regions with moderate to high malaria transmission.
