Contacts: Angela Heisel, Public Affairs University of New Mexico Health Sciences Center 505/272-3651

Ruey-Li Hwang, Corporate Communications, Cerus Corporation 925/288-6017

CONCORD, CA, October 5, 2005 - Cerus Corporation (NASDAQ: CERS) and the University of New Mexico (UNM) today announced the funding of a consortium designed to develop a prophylactic vaccine against Francisella tularensis , the bacterium that causes the disease Tularemia. Francisella is a potential bioterror agent against which no effective vaccine exists. The consortium, led by Dr. Rick Lyons, M.D. Ph.D. of UNM, will focus on developing a Tularemia vaccine based on Cerus' proprietary KBMA vaccine technology.

The $23 million research and development contract, of which Cerus will receive $2.8 million over three years, is funded by the National Institute of Allergy and Infectious Diseases (NIAID), a division of the National Institutes of Health. Other members of the consortium include Lovelace Respiratory Research Institute, Arizona State University , and the University of Texas , San Antonio .

KBMA vaccines consist of killed, but metabolically active bacteria. They offer the potential to combine the efficacy of live vaccines with the safety of killed vaccines. KBMA technology can be applied whenever a metabolically active, but non-replicating microorganism is a safer alternative to a conventional live vaccine, such as in biodefense applications. While Francisella has been a priority agent for biodefense vaccine developers, there is limited data regarding the molecular determinants against which a vaccine should be targeted. The KBMA technology permits vaccine development based on the whole microorganism, thereby obviating the difficult problem of defining the relevant target antigens.

"The funds for this research will be important in developing strategies that are not only applicable to a vaccine for Franciscella but will also assist in defining a paradigm for developing vaccines against other emerging infections," according to Dr. Lyons, Director of the Center for Infectious Diseases and Immunity at the University of New Mexico Health Science Center. "Emerging infections are recognized as a significant medical issue and innovative approaches to vaccine development are required. We are extremely excited about the opportunity provided to us by NIAID."

"The three-year $2.8 million for Tularemia research allows us to further explore commercial applicability of our KBMA vaccine technology," said Claes Glassell, president and chief executive officer of Cerus. "Together with ongoing research being conducted under an NIH grant to develop a more potent vaccine against anthrax, we are now building critical mass in our infectious disease programs."

Tularemia, also known as Rabbit Fever, is a disease caused by the bacterium Franciscella . Tularemia is typically carried by rodents and rabbits. People can become infected through the bite of insects which harbor the bacterium, by handling sick animals, by eating or drinking contaminated food, or by inhaling airborne bacteria. There is increasing awareness that Franciscella could be deliberately released in an act of bioterrorism or war. The development of a vaccine against Tularemia has been limited by a lack of information regarding the mechanisms required to protect against this disease.

ABOUT CERUS

Cerus Corporation is developing novel products for cancer, infectious disease and blood safety based on multiple, innovative technology platforms. The company is building a pipeline of next generation cancer immunotherapies by combining its proprietary attenuated Listeria vector platform with promising disease antigens. These products are designed to stimulate innate and T cell immune pathways, generating highly potent anti-tumor responses. The company's KBMA vaccine technology has potential broad applications against multiple pathogens. Cerus is applying its Helinx technology to develop the INTERCEPT Blood System, which is designed to enhance the safety of blood components through pathogen inactivation. The company's strategy is to leverage the broad potential of its technologies and products through alliances. Cerus' partners to date include MedImmune and Johns Hopkins University for cancer immunotherapy, and Baxter International and BioOne for the INTERCEPT Blood System.

ABOUT THE UNIVERSITY OF NEW MEXICO

The University of New Mexico School of Medicine provides added value to health care through leadership in providing innovative, collaborative education; advancing frontiers of science through research critical to human health; delivering health care services that are at the forefront; and facilitating partnerships with public and private biomedical and health enterprises. The Center for Infectious Diseases and Immunity (CIDI) is one of four signature research programs at the UNM School of Medicine. The mission of the CIDI is to develop and enhance collaborative programs among the community of researchers, physicians and businesses in New Mexico in order to address the threats of infectious diseases to the New Mexico population and the world by developing new vaccines, therapeutics and diagnostics.

Statements in this news release regarding potential efficacy and safety of products, product development and commercial potential are forward-looking statements that involve risks and uncertainties. Actual results could differ materially from the above forward-looking statements as a result of certain factors, including the risks and uncertainties inherent in developing biotechnology products based on new technologies, the timing and results of clinical trials and other development activities, market acceptance of Cerus Corporation's products, actions by regulatory authorities at any stage of the development process, the availability of governmental or third party reimbursement for the use of Cerus Corporation's products, the size of the market for the company's products, competitive conditions, manufacturing capabilities, and other factors discussed in the company's Form 10-K/A for fiscal 2004, as well as in other reports filed from time to time with the Securities and Exchange Commission. The company assumes no obligation to update any forward-looking statements.