AVANT Opens State-of-the-Art Vaccine Manufacturing Facility in Fall River, MA.

NEEDHAM & FALL RIVER, Mass. -- New Plant Expands AVANT's Product Production Capability While Providing Increased Efficiencies And A New Platform For Growth

MA Governor Mitt Romney Hails The Plant As The Beginning Of A Life Sciences Industry Center In Fall River

AVANT Immunotherapeutics, Inc., (NASDAQ:AVAN), a leading life sciences company specializing in the development of innovative vaccines and therapeutics, today unveiled its state-of-the-art, pilot manufacturing facility in Fall River. The facility will develop and manufacture AVANT's "next generation" vaccines for Phase I, II and III clinical trials and eventual commercial sale. The plant is located at 151 Martine Street in MassDevelopment's South Coast Research and Technology Park adjacent to Interstate 195. The building also houses UMass Dartmouth's Advanced Technology & Manufacturing Center.

According to AVANT President and CEO Una S. Ryan, Ph.D., who is also Chairman of the Massachusetts Biotechnology Council: "AVANT's Fall River pilot manufacturing facility will develop products that prevent disease, improve the quality of life and are often life-saving. The new facility provides us with strategically important growth opportunities and access to a highly desirable workforce. It is conveniently located at the crossroads of Interstate 195 and Route 24 in close proximity to Boston and Providence. From a strategic business perspective, the Fall River plant complements AVANT's research, process development and clinical expertise by adding cutting edge manufacturing capabilities and increased efficiencies."

AVANT's current vaccine and immunotherapeutics product portfolio includes cholesterol management, cardiac surgery, infectious disease, biodefense and food safety. The company has three marketed products: Rotarix(R), a two dose oral vaccine against rotavirus, a disease which causes infant diarrhea, Megan(R)Egg, a vaccine to protect against Salmonella infection in laying hens and eggs and Megan(R)Vac, a vaccine to protect against Salmonella infection in broilers. AVANT also has six products in clinical development, including CETi-1, a therapeutic vaccine for cholesterol management and TP10, an innovative therapy for cardiac surgery.

U.S. Senator Edward M. Kennedy (D- Mass), who has worked with AVANT on key issues related to health care R&D, welcomed the company's decision to expand to Fall River: "AVANT is in the vanguard of current research and development on some of the most promising vaccines and biochemical products to prevent and treat disease. The Fall River facility is a welcome addition to our state's leadership on the cutting edge of modern health care and it will also be a significant new economic engine for all the communities in Southeastern Massachusetts. CEO Una Ryan is an outstanding Chair of the Massachusetts Biotechnology Council, and I commend her for her major role in the biotech revolution and all she's done for our state."

The Fall River facility is an 11,800 square foot, multi-product, full service, GMP (Good Manufacturing Practice) manufacturing facility. With corporate headquarters and R&D operations in Needham, AVANT is the first life science company to begin operations in Fall River. Dr. Ryan said Governor Mitt Romney was instrumental in convincing AVANT to expand operations in Massachusetts by touting the state's pro-business incentives, such as the manufacturing tax credit recently put in place for the biotech industry. "With the state's educated workforce and top-of-the-line infrastructure, AVANT could not have chosen a better place to expand," said Romney. "This impressive facility serves as a new source of growth for the Fall River region and will encourage additional life science companies to locate here." Mass Development, the state's finance and economic development agency, provided financing of up to $2.2 million to AVANT to buy equipment and renovate space.

AVANT's pilot facility will manufacture genetically altered, harmless bacterial organisms for potentially life-saving vaccines for clinical trials and eventual commercial sale. Initially staffed by approximately a dozen employees, the company expects to expand the workforce to 20 in 2005. Fall River Mayor Edward Lambert commented: "The City of Fall River is proud to have AVANT as its first life science company. The industry is a vital part of the new Massachusetts economy and offers the promise of being a major job generator for many decades to come."

The Fall River facility will have two manufacturing suites, a purification suite, two quality control labs, supporting area clean rooms, future expansion areas and office space. The facility will apply AVANT's VitriLife(R) preservation technology, a patented process that enables the production of thermostable (room temperature) vaccines for its own and its partners' product lines.

Dr. Ryan concluded: "With today's opening AVANT embarks on a very important chapter of its history and development as a leading life sciences company. We are now able to manufacture for clinical development and eventual sale life-saving vaccines to address as of yet unmet global health care needs. I am very excited about our new partnership with Fall River and believe that it will be a great place for life science companies like AVANT to do business."

The facility will operate in full compliance with US FDA requirements, European regulations and guidelines and in accordance with current Good Manufacturing Practice (cGMP) guidelines.

About AVANT Immunotherapeutics, Inc.

AVANT Immunotherapeutics, Inc. discovers, develops and sells innovative vaccines and therapeutics that harness the human immune system to prevent and treat disease. The company has developed a broad, well-staged pipeline of vaccines and therapeutics for large, high-value, under-served markets. Three of AVANT's products are marketed, including two food safety vaccines and an oral human rotavirus vaccine, which gained its first marketing approval in Mexico in July 2004. 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 has also assembled a technology platform that enables the creation of rapid-protecting, single-dose, oral vaccines that remain stable without refrigeration. The company is developing applications of this vaccine technology in four areas: biodefense, travelers' vaccines, global health needs, and human food safety. AVANT's goal is to demonstrate proof-of-concept for its products before leveraging further development through both traditional pharmaceutical partnerships and collaborations with governmental and other organizations.

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, 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), Ty800and 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 Rotarix(R), Megan(R)Vac 1, Megan(R)Egg and other future products; (8) changes in existing and potential relationships with corporate collaborators; (9) the availability, cost, delivery and quality of clinical and commercial grade materials supplied by contract manufacturers; (10) 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; (11) the ability to obtain substantial additional funding; (12) the ability to develop and commercialize products before competitors; (13) the ability to retain certain members of management; and (14) 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.