Gates gives $750m to fight deadly childhood diseases

Bill Gates, the chairman of Microsoft, has given $750m, his biggest ever donation, to an alliance dedicated to ending deaths from vaccine-preventable diseases among the poorest children in the world.

The gift, which is announced today, ranks as one of the largest donations made by a living philanthropist. It goes to the Global Alliance for Vaccines and Immunisation (Gavi), which Mr Gates helped to set up in 2000.

It brings the Bill and Melinda Gates Foundation's donations to Gavi to more than $1.5bn (£800m). "We can say very strongly that we have never made a better investment," said Mr Gates, named by Forbes magazine as the richest man in the world and worth an estimated $46bn.

The Norwegian government announced a grant of $290m at the same time, bringing Gavi's new money to more than $1bn.

In an interview with the Guardian at Microsoft's Seattle headquarters, Mr and Mrs Gates said they hoped other governments would put in funds to reach the target set by the World Health Organisation of $8bn-$12bn over 10 years, which would allow more than 90% of the world's children to receive immunisation by 2015.

"Today, a child's access to life-saving vaccines too often depends on where he or she lives in the world, and that's unacceptable," Mrs Gates said.

"Vaccines taken for granted in rich countries still don't get to millions of children in the developing world. It's time for donors, both public and private, to dramatically step up their efforts to close the immunisation gap."

Mr Gates called for more governments to help, and praised the UK. "I'm very excited about the leadership they are providing. The prime minister had a piece that he wrote that talked about Africa and its challenges as one of the top priorities. It is pretty novel that the leader of a developed country is giving top priority to this issue."

He also praised the international finance facility (IFF) proposed by the chancellor, Gordon Brown, to raise money to alleviate poverty and disease in poor countries. Gavi is expected to be the pilot project for the IFF. Government-backed bonds will be floated on financial markets to raise money for vaccines and research.

"It would provide a lot of the additional funding Gavi needs to achieve its very ambitious goals, saving 10 million lives," said Mr Gates.

Gavi is is an alliance of governments, UN agencies, NGOs, foundations and other institutions, which works to bring routine and new vaccines to children in the developing world. Some 27 million children are not immunised each year, which in 2002 was estimated to have resulted in 2.1 million deaths from diseases that have disappeared in the west, such as diphtheria, measles and tetanus.