VaxGen was a biopharmaceutical company based in the San Francisco Bay Area. Founded in 1995 and based in South San Francisco, California, the company was engaged in the development of vaccines that immunize against infectious disease, notably AIDS. On July 28, 2010, VaxGen Inc. was acquired by diaDexus, Inc. in a reverse merger transaction.; diaDexus filed for bankruptcy in 2016. VaxGen, Inc. does not have significant operations.