GlaxoSmithKline, the UK-based pharmaceuticals group, gave impetus on Wednesday to an international flu vaccine stockpile designed to assuage concerns that the poor will be unable to protect themselves during the next pandemic.

The company said that it would donate 50m doses of its pre-pandemic H5N1 vaccine to the World Health Organisation. It also pledged to supply at low cost further doses and its proprietary "adjuvant" - a chemical that makes vaccines more potent.