Altimmune, Inc. Common Stock, also called Altimmune, is a clinical stage immunotherapeutic biotechnology company, which is focused on the discovery and development of products to stimulate robust and durable immune responses for the prevention and treatment of diseases. Read More Its portfolio includes RespirVec and Densigen that targets to stimulate the elements of the human immune system to treat respiratory diseases, chronic infections, and cancer. The company was founded in 1997 and is headquartered in Gaithersburg, MD.