Pneumonia vaccine 'to save thousands of lives'
24 January 2011 Last updated at 19:08 GMT
A vaccine against pneumonia - the world's biggest killer of children - is being introduced in Africa and other poor countries across the world.
But one of the world's richest women - Melinda Gates - has warned that children will continue to die of preventable illnesses unless governments pledge more money for immunisation.
She was speaking on a visit to Kenya, from where the BBC's health correspondent Fergus Walsh sent this report.