Quadrant Holdings, a bioscience company in Cambridge, England, has developed a method of drying vaccines so that they can be transported without having to be refrigerated. The secret lies in removing the water from the vaccine sample. By replacing the water with a sugar called trehalose, scientists can dry vaccines without damaging them. This ability of trehalose was discovered in the 1980s by Bruce Roser, the founder of Quadrant and the first to apply trehalose to the preservation of unstable biological samples. Quadrant has been working with the World Health Organisation on applying the technique to the polio vaccine and is on the point of signing licensing deals with vaccine producers to manufacture heat-stable vaccines for other diseases.