Each side is footing half of the $75m bill for the programme, which also aims to cut down the number of syringes which are reused in China's health clinics.

The use of dirty needles, particularly when immunising children, is blamed for much of the spread of hepatitis and other infectious diseases in China, including Aids.

Rural difficulties

Quarter of a million people in China die from hepatitis B, which damages the liver and can cause liver cancer and liver failure.

"People forget that two-thirds of hepatitis B infections worldwide are in China. If we can make progress here, we're getting somewhere," said James Jones from the Vaccine Fund.

"That's clearly something that folks in many of the urban areas can cover, but its certainly beyond the reach of many rural residents whose annual per capita income might be less than $100," said Carol Bellamy of Unicef, which will administrate the vaccination programme.

At the moment, rural immunisation runs at only 40% in many rural areas, and in some districts is as low as 10%.

"The idea is to build (hepatitis B vaccination) into routine immunisation and not be a chargeable health action at a district clinic," said Ms Bellamy.

Safe syringes

The project aims to vaccinate more than one-third of the children born in China each year.

It will also provide more than 500 million auto-disposable syringes.

These have a system which prevents them being used a second time and are seen as a useful tool in preventing the spread of diseases through needles.

As a condition of the hepatitis project, China has pledged to use auto-disposable syringes for all injections over the next five years.