The British prime minister, Gordon Brown, will this week announce an extra $1bn to pay for more vaccines and immunisation for children in the developing world and boost healthcare systems.

The money — nearly half of which will come from the UK — will be channelled through the Global Alliance for Vaccines and Immunisation (Gavi), which already funds major programmes to protect children from diseases including measles and diphtheria. But in a move away from its original remit, Gavi will distribute the money not only to support vaccination but also to improve health systems in the 72 poorest countries in the world.

Countries will apply to Gavi for the funds to help them carry out national plans to train more medics and clinic staff and improve their clinics’ buildings and equipment. The cash will be available to help governments improve drug supplies, so that essential medicines reach people in remote areas as well as major cities, and pay for drugs they need but cannot afford.

The British government has shown itself increasingly keen to support healthcare systems in the developing world rather than fund programmes to fight specific diseases such as tuberculosis. There is increasing concern that crucial millennium development goals (MDG) will be missed, particularly those aimed at cutting childbirth mortality rates for mothers and babies, a cause for which the prime minister’s wife, Sarah Brown, campaigns. Only 12 per cent of low-income countries are on track to meet MDG targets to reduce child mortality and 75 per cent of low-income countries continue to have very high maternal mortality rates. Healthcare systems, however, receive only 20 per cent of the funding available from international donors for health.

“It is unacceptable that nearly 10 million children under the age of five die every year and a mother dies in childbirth every minute,” said the UK’s international development secretary, Douglas Alexander.

“Most of these deaths could have been prevented if there were better health systems and services in place. That is why we need to ensure that we have more money now to make real progress on advancing the standard of healthcare in the developing world.” The UK will put in $405m of the $1bn. The rest will come from Norway, the Netherlands and Australia.

Mr. Brown and Mr. Alexander will announce the new money in New York tomorrow (Sept 23, 2009), when they will also lead a push for free healthcare for millions in the developing world. Many of the poorest countries levy charges which deter people from going to the doctor or prevent them from getting the treatment they need.

The $1bn will be paid through the International Finance Facility on Immunisation. National governments enter into legally binding commitments to provide the money over a 20-year period, allowing bonds to be issued on the capital markets. Those funds are then passed to Gavi.