At its factory in Swiftwater, Pennsylvania, Sanofi-Pasteur, a division of the French-based group Sanofi-Aventis, has received one of the largest orders of eggs ever placed by the US government.

The deal, worth up to $41m over five years, is part of the company's efforts to ensure a sufficient supply of the eggs in which it will mass produce its vaccine against a potential bird flu pandemic which could kill millions of people.