Avant Signs Agreement with Pfizer for Development of Animal Health Vaccines.

NEEDHAM, Mass. -- AVANT Immunotherapeutics, Inc. (Nasdaq: AVAN) announced today the signing of an extended collaborative research and development agreement with Pfizer Inc aimed at the discovery and development of vaccines to protect animals. The collaboration will employ vaccine technologies owned by AVANT.

Under the agreement, Pfizer and AVANT will conduct a joint research program funded by Pfizer to develop prophylactic and therapeutic vaccines to protect livestock and companion animals from respiratory and enteric diseases. Financial terms were not disclosed.

"We are very pleased to extend our collaboration with Pfizer to leverage the value of AVANT's vaccine technology in a significant market opportunity outside AVANT's own focus on human health care," said Una S. Ryan, Ph.D., President and Chief Executive Officer of AVANT Immunotherapeutics, Inc. Pfizer Animal Health is a leader in the global industry.

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. AVANT has three products on the market and five 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 products for biodefense, travelers' vaccines, global health, and pandemic flu needs based on AVANT's rapidly-protecting, oral, single-dose, 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 that are subject to a variety of risks and uncertainties and reflect AVANT's current views with respect to future events and financial performance. There are a umber of important factors that could cause the actual results to differ materially from those expressed in any forward-looking statement made by AVANT. 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 any other microbes used as bioweapons and other disease causing agents; (3) the ability to successfully complete development and commercialization of TP10, CETi-1, 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, Glaxo; (9) Glaxo's strategy and business plans to launch and supply Rotarix[R] worldwide, including in the U.S. and other major markets; (10) changes in existing and potential relationships with corporate collaborators; (11) the availability, cost, delivery and quality of clinical and commercial grade materials supplied by contract manufacturers; (12) 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; (13) the ability to obtain substantial additional funding; (14) the ability to develop and commercialize products before competitors and that are superior to the alternatives developed by competitors; (15) the ability to retain certain members of management;(16) AVANT's expectations regarding research and development expenses and general and administrative expenses; (17) DVC's ability to complete clinical trials and perform under its agreement; (18) AVANT's expectations regarding CETP's ability to improve cholesterol levels and AVANT's ability to develop and commercialize CETP; (19) AVANT's expectations regarding cash balances, anticipated royalty payments and expenses, including infrastructure expenses; and (20) other factors detailed from time to time in filings with the Securities and Exchange Commission. You should carefully review all of these factors, and you should be aware that there may be other factors that could cause these differences. These forward-looking statements were based on information, plans and estimates at the date of this report, and we do not promise to update any forward-looking statements to reflect changes in underlying assumptions or factors, new information, future events or other changes.