(CNN) -- The British government will donate an additional $1.32 billion (?814 million) to aid projects vaccinating children in developing countries, the British Prime Minister David Cameron said Monday in a speech.
The PM made the announcement at the Global Alliance for Vaccines and Immunization (Gavi) conference in London, where Bill Gates, the billionaire philanthropist and co-founder of Microsoft, also pledged $1 billion to the vaccine program.
Cameron said: "In addition to our existing support for Gavi, we will provide ?814 million of new funding up to 2015. This will help vaccinate over 80 million children and save 1.4 million lives."
The British Department for International Development says vaccines save the lives of 7,000 children every day.
Gates told the conference that his Bill and Melinda Gates Foundation was pledging an additional $1 billion over the next five years to help the vaccination campaign.
Gates said: "It's not every day you give away a billion dollars but for a cause like this it's exciting to be doing this."
The conference is designed to encourage richer countries to donate more money to the global vaccine program, particularly to vaccinate more children against pneumonia and diarrhea.
According to Gavi -- an organization set up to increase access to immunization in the world's poorest countries -- one child dies every 20 seconds from a "vaccine-preventable disease."
Two million under-fives die from pneumonia each year despite the existence of a vaccine to protect them, says Gavi.
A recent study by the charity Save the Children reported that there are about 24 million children in the world, mostly in developing countries, who have no access to vaccines.