Denatured collagen derived from animals is used as a stabilizer in a number of pharmaceuticals, including all live attenuated vaccines, such as measles, tetanus, diphtheria and yellow fever vaccines. However, the potential for contamination such as with bovine spongiform encephalopathy (BSE) is an ongoing fear, making it increasingly important to develop recombinant sources of gelatin. Last week FibroGen Inc. signed its first deal to commercialize its synthetic gelatins, reaching an agreement to co-develop the substances for use in vaccines