The largest contract awarded under the Bush Administration's $5.6 billion program to develop countermeasures against weapons of mass destruction, dubbed Project Bioshield, is in jeopardy. FDA is prohibiting human safety testing of a new anthrax vaccine developed by VaxGen, a California-based biotechnology company, because of questions about the vaccine's stability. To address FDA's concerns, VaxGen may have to generate new data on the current vaccine formulation or make improvements to it. In 2004, the Department of Health & Human Services awarded VaxGen $878 million to supply the Strategic National Stockpile with 75 million doses of its recombinant vaccine. In a letter dated Nov. 3, HHS informed the company that FDA's decision puts the contract in jeopardy and "the government may terminate for default." At press time, a decision on the contract was imminent. VaxGen was originally scheduled to begin delivering the vaccine to the national stockpile in November 2005; delivery is now not expected to occur until 2008.