The company’s submission provides the U.S. Government with the critical option to select a domestic source to meet planned procurement of 25 million doses of rPA vaccine

Emergent BioSolutions Inc. (NYSE:EBS) announced today that it has submitted a proposal in response to a request for proposal (RFP) issued by the U.S. Department of Health and Human Services (HHS) for a recombinant protective antigen anthrax vaccine (rPA). Emergent’s rPA vaccine candidate is a reformulated and more stable form of the rPA 102 vaccine originally developed at the U.S. Army Medical Research Institute of Infectious Diseases (USAMRIID) and is well-positioned to be a leading candidate for an award under this RFP. One Phase II clinical trial of rPA 102 has been completed.

HHS’s RFP is designed to meet the government’s stated goal to procure 25 million doses of an rPA anthrax vaccine for the Strategic National Stockpile (SNS). In the event that Emergent receives an award under the rPA RFP, doses of rPA procured by HHS would be in addition to the 18.75 million doses of the company’s FDA-licensed product, BioThrax® (Anthrax Vaccine Adsorbed), that HHS is procuring under the existing $448M contract with Emergent. HHS has indicated that any awards under the rPA RFP would be granted at the end of 2008, at the earliest.

“We are very pleased with our submission in response to this RFP, and we are confident that our rPA 102 vaccine is a leading candidate to be selected as an advanced rPA anthrax vaccine. Our company is proud of our proven track record of delivering critical biodefense countermeasures to the U.S. government, and we believe our reputation as the premiere domestic biodefense supplier, coupled with our development and manufacturing expertise, uniquely situates Emergent to meet HHS’s stated commitment to procure 25 million doses of a recombinant anthrax vaccine for the Strategic National Stockpile,” said Fuad El-Hibri, chairman and chief executive officer of Emergent BioSolutions.

“Considerable resources have been devoted to improving the stability of the rPA 102 vaccine. Analytical testing and non-clinical data indicate the changes made to the formulation of rPA 102 has significantly improved the stability of this vaccine candidate. We are confident that the formulation changes have addressed previous concerns regarding the stability of the product. We believe that the current formulation will meet the U.S. government’s stability requirements for an rPA vaccine,” said Dr.