Public and private donors have pledged a whopping $4.3 billion dollars to a global vaccine charity, allowing it to carry out plans to immunize more than 250 of the world’s poorest children against life-threatening diseases by 2015.

The Geneva-based GAVI Alliance said the amount exceeded what it had been seeking to plug a budget shortfall. The largest amounts came from the UK ($1.34 billion), the Bill & Melinda Gates Foundation ($1 billion), Norway ($677 million) and the US ($450 million).

In his address to the donor summit in London (June 13), British Prime Minister David Cameron said that the UK’s support for GAVI “will help vaccinate over 80 million children and save 1.4 million lives. That’s one child vaccinated every two seconds for five years.”

Other governments more than doubled their previous commitments and new donors, such as Japan and Brazil, gave for the first time. GAVI’s largest corporate donor is “La Caixa” Foundation of Barcelona which specializes in global welfare projects.

Two new donors include mining giant Anglo American, which pledged $3 million to the UK Government’s matching fund initiative, and the UK-based international charity ARK (Absolute Return for Kids), which specializes in philanthropic investment in health projects in Africa.

Some relief agencies have criticized GAVI for having too cozy a relationship with drug companies but GAVI says it needs to work with pharmaceutical companies to keep vaccine supplies flowing.

Some vaccine manufacturers have said they will offer lower prices on a range of life-saving vaccines supported by GAVI, including a two-thirds reduction on the rotavirus vaccine which combats diarrhea.

Bill Gates defended the alliance he helped found, saying it gets good prices from drug companies but that he is eager to see if Indian and Chinese pharmaceutical companies can increase their output to help bring prices down.

Co-financing by developing countries will also help lower prices for immunization programs. GAVI estimates that the level of co-financing projects will triple by 2015 to $100 million.