AVANT's CholeraGarde(R) Vaccine Development Program Receives Further Funding from the Gates Foundation; New Support Follows Successful Phase 2 Clinical Trials.

NEEDHAM, Mass. -- AVANT Immunotherapeutics, Inc. (NASDAQ: AVAN) today announced that the International Vaccine Institute ("IVI") has received $21 million in funding from the Bill & Melinda Gates Foundation for a Cholera Vaccine Initiative (CHOVI), which will include conducting further clinical trials of CholeraGarde(R), AVANT's cholera vaccine. Under the direction of John D. Clemens, M.D., IVI plans to conduct Phase 2 and Phase 3 clinical trials of CholeraGarde(R) in Bangladesh and India beginning in 2007. IVI will be purchasing clinical materials produced at AVANT's Fall River, MA manufacturing facility for the trials.

"Cholera is a devastating disease in the developing world," said Una S. Ryan, Ph.D., President and Chief Executive Officer of AVANT Immunotherapeutics, Inc. "We are very pleased to build on the success of our previous Phase 2 clinical trial by continuing our partnership with the IVI for the development of CholeraGarde(R) vaccine. The development of a safe and effective cholera vaccine is important for protecting residents, travelers and military personnel from cholera in endemic areas. We see the initiation of these trials as serving the dual role of addressing a significant health issue in the developing world and advancing development of AVANT's vaccine franchise. We expect to initiate our own Phase 3 study of CholeraGarde(R) in early 2007 to support an application for U.S. and E.U. approval for use in travelers and military personnel."

IVI is founded on the belief that the health of children in developing countries can be dramatically improved by the development, introduction and use of new and improved vaccines and these vaccines should be developed through a dynamic interaction among science, public health and business. The IVI's earlier collaborations with AVANT were supported by the Diseases of the Most Impoverished (DOMI) Program, which was also funded by the Bill & Melinda Gates Foundation. The current CHOVI program will include the development of CholeraGarde(R) as well as an oral killed whole cell cholera vaccine from Vietnam.

"I am pleased to see continued clinical development of the CholeraGarde(R) vaccine for use in endemic regions," stated John D. Clemens, M.D., Director of the International Vaccine Institute. "Our partnership with AVANT underscores IVI's mission of accelerating vaccine development to relieve the burden of disease in developing countries. IVI works with vaccine partners like AVANT to pursue vaccine development that otherwise may not occur."

AVANT is developing a series of oral, single-dose bacterial vaccines to prevent diarrhea and dysentery in travelers and military personnel in developed countries and in people living in developing countries with high rates of water and food borne diseases. In addition to the CholeraGarde(R) vaccine, AVANT's Ty800 typhoid fever vaccine is in a Phase 1/2 clinical trial sponsored by the National Institutes of Health. In preclinical development, AVANT is advancing a vaccine against enterotoxigenic E. coli (ETEC), the most common form of travelers' diarrhea, and a Shigella sonnei vaccine, aimed at the Shigella strain most often contracted by travelers and associated with domestic outbreaks in the United States. Many of these vaccines could also meet the healthcare requirements of less developed countries, where the need for vaccines against water- and food-borne diseases is particularly acute.

About AVANT Immunotherapeutics, Inc.

AVANT Immunotherapeutics, Inc. discovers and develops innovative vaccines and therapeutics that harness the human immune system to prevent and treat disease. Six of AVANT's products are in clinical development, including a treatment to reduce complement-mediated tissue damage associated with cardiac bypass surgery and a novel vaccine for cholesterol management. AVANT is also developing a pipeline of bacteria-fighting products for biodefense, travelers' vaccines, and global health needs based on AVANT'S rapid-protecting, single-dose, oral and temperature stable vaccine technology.

Additional information on AVANT Immunotherapeutics, Inc. can be obtained through our site on the World Wide Web: http://www.avantimmune.com.

Safe Harbor Statement Under the Private Securities Litigation Reform Act of 1995: This release includes forward-looking statements which reflect AVANT's current views with respect to future events and financial performance. These forward-looking statements are based on management's beliefs and assumptions and information currently available. The words "believe", "expect", "anticipate", "intend", "estimate", "project" and similar expressions which do not relate solely to historical matters identify forward-looking statements. Investors should be cautious in relying on forward-looking statements because they are subject to a variety of risks, uncertainties, and other factors that could cause actual results to differ materially from those expressed in any such forward-looking statements. These factors include, but are not limited to: (1) the integration of multiple technologies and programs; (2) the ability to adapt AVANT's vectoring systems to develop new, safe and effective orally administered vaccines against anthrax and plague or other bioterrorism threats or emerging health care threats; (3) the ability to successfully complete development and commercialization of TP10, CETi-1, AVANT's CholeraGarde(R) Vaccine Development Program Receives Further Financial Support from the Gates Foundation CholeraGarde(R) (Peru-15), Ty800 and other products; (4) the cost, timing, scope and results of ongoing safety and efficacy trials of TP10, CETi-1, CholeraGarde(R) (Peru-15), Ty800 and other preclinical and clinical testing; (5) the ability to successfully complete product research and further development, including animal, pre-clinical and clinical studies of TP10, CETi-1, CholeraGarde(R) (Peru-15), Ty800 and other products; (6) the ability of the Company to manage multiple late stage clinical trials for a variety of product candidates; (7) the volume and profitability of product sales of Megan(R)Vac 1, Megan(R)Egg and other future products; (8) the process of obtaining regulatory approval for the sale of Rotarix(R) in major commercial markets, as well as the timing and success of worldwide commercialization of Rotarix(R) by our partner, GlaxoSmithKline; (9) changes in existing and potential relationships with corporate collaborators; (10) the availability, cost, delivery and quality of clinical and commercial grade materials supplied by contract manufacturers; (11) the timing, cost and uncertainty of obtaining regulatory approvals to use TP10, CETi-1, CholeraGarde(R) (Peru-15) and Ty800, among other purposes, for adults undergoing cardiac surgery, to raise serum HDL cholesterol levels and to protect travelers and people in endemic regions from diarrhea causing diseases, respectively; (12) the ability to obtain substantial additional funding; (13) the ability to develop and commercialize products before competitors; (14) the ability to retain certain members of management; and (15) other factors detailed from time to time in filings with the Securities and Exchange Commission. We expressly disclaim any responsibility to update forward-looking statements.