VaxGen Sells Anthrax Vaccine Program and Related Assets and Technology to Emergent BioSolutions, Inc.

SOUTH SAN FRANCISCO, Calif., May 5 /PRNewswire-FirstCall/ -- VaxGen, Inc. (OTC Bulletin Board: VXGN.OB), a biopharmaceutical company, announced today it has completed the sale of all assets and rights related to its recombinant protective antigen (rPA) anthrax vaccine product candidate and related technology to Emergent BioSolutions, Inc. Under the terms of the transaction, Emergent BioSolutions paid VaxGen $2 million upon execution of the definitive agreement and may be obligated to pay up to an additional $8 million in milestone payments, plus specified percentages of future net sales.

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"We have marketed our anthrax vaccine candidate and related technology very broadly over the last 12 months," said James P. Panek, VaxGen President and CEO. "In Emergent, we believe we have identified a partner whose expertise in the field and track record in contracting with government agencies maximizes the chances of returns for our shareholders."

About VaxGen

VaxGen is a biopharmaceutical company based in South San Francisco, California. The company owns a state-of-the-art biopharmaceutical manufacturing facility with a 1,000-liter bioreactor that can be used to make cell culture or microbial biologic products. For more information, please visit the company's web site at http://www.vaxgen.com.

Note: This press release contains "forward-looking statements" within the meaning of the federal securities laws, including statements regarding the potential receipt of milestone payments and specified percentages of future net sales from Emergent BioSolutions. These statements are subject to risks and uncertainties that could cause actual results and events to differ materially from those anticipated. Additional information concerning these and other risk factors is contained in VaxGen's Annual Report on Form 10-K for the year ended December 31, 2007. Readers are cautioned not to place undue reliance on these forward-looking statements that speak only as of the date of this release. VaxGen undertakes no obligation to update publicly any forward- looking statements to reflect new information, events, or circumstances after the date of this release except as required by law.

SOURCE VaxGen, Inc.