The annual production of vaccine against the A(H1N1) is just enough to vaccinate half the world's populations, according to the World Health Organisation.

Manufacturers are able to produce around 3 billion doses, while in May the WHO was expecting a capacity of 4.9 billion.

The organisation has announced that in November it will begin distributing vaccine to more than 90 developing countries. The doses have been provided by a number of wealthier countries which are expecting to have a surplus.