The GAVI vaccines alliance said on Thursday it had raised $8.8 billion from international donor governments, companies and philanthropic foundations to fund its immunisation programmes through to 2025.
At a funding summit in London, GAVI said the pledges had exceeded its target of $7.4 billion, and would "help immunise 300 million more children in the world's poorest countries against diseases like measles, polio and diphtheria".
The vaccines alliance also said it had raised $567 million towards an initial goal of $2 billion from international donors for an Advanced Market Commitment to buy future Covid-19 vaccines for poor countries.
The deal would help secure enough Covid-19 vaccine doses - when the shots have been developed - for poor countries to immunise healthcare workers and those at high risk, it said, as well as creating a "buffer of doses" for use when needed.
GAVI, the World Health Organisation and the United Nations children's fund UNICEF have warned that 80 million children under the age of one are at risk of disease due to disruptions to vital immunisation programmes because of the Covid-19 pandemic caused by the new coronavirus.
Britain, which hosted the summit, was among the largest donor to GAVI's core $8.8 billion funding, pledging the equivalent of 330 million pounds ($416 million) per year over the next five years, GAVI said.
British Prime Minister Boris Johnson said GAVI could count on the UK's full contribution to help "the triumph of humanity over disease, now and for the generations that follow".
Other top donors included the Bill & Melinda Gates Foundation, which gave $1.6 billion for the period up to 2025, and the governments of Norway, Germany and the United States.
"To beat the Covid-19 pandemic, the world needs more than breakthrough science. It needs breakthrough generosity. And that's what we're seeing today as leaders across the public and private sectors are stepping up to support GAVI," Bill Gates, co-chair of the philanthropic Gates Foundation, told the summit.
He added that when Covid-19 vaccines are ready, the AMC funding would ensure people all over the world can access them.
GAVI said eight of the government donors were countries making their first ever pledge to the vaccines alliance: These were Bhutan, Burkina Faso, Cameroon, Finland, Greece, New Zealand, Portugal and Uganda.
GAVI is a public-private partnership backed by the Bill & Melinda Gates Foundation, the WHO, the World Bank, UNICEF and others, which arranges bulk buys to reduce vaccine costs for poor countries.