OTTAWA (CBC) - It would take $39 billion US to save the lives of 5.3 million children who will otherwise die of pneumonia by 2015, the United Nations said Monday.

The World Health Organization and the UN Children's Fund launched a joint appeal to fund pneumonia prevention and treatment at a cost of less than $13 US per child in 68 developing countries,

"We know the strategy will work, and if it is applied in every high-burden country, we will be able to prevent millions of deaths," Margaret Chan, director general of the World Health Organization, said in a statement.

Pneumonia accounts for about 20 per cent of all child deaths every year, killing 1.8 million children under the age of five every year.

The plan calls for:

The goal is to expand vaccine coverage, exclusive breastfeeding rates and access to treatment to 90 per cent by 2015.

"This is very simply the biggest killer people never hear about," said Orin Levine, a public health expert at Johns Hopkins Bloomberg School of Health, who has advised WHO and UNICEF.

If the goal is met, the agencies said it will lead to a reduction in child pneumonia deaths by 65 per cent and cut the number of severe pneumonia cases in children by 25 per cent, compared to 2000 levels.

Since 2000, a vaccine to protect children from pneumonia has existed, but it is only available in wealthy countries.