Project BioShield

Medical Countermeasures for Radiation Exposure

The Threat

A radiological or nuclear attack on the U.S. homeland could take a number of forms, including: contamination of food or water with radioactive material; placement of radiation sources in public locations; detonation of radiological dispersal devices that scatter radioactive material over a populated area; an attack on a nuclear power plant or a high-level nuclear waste storage facility; or an improvised nuclear device.  The acquisition and ready availability of medical countermeasures for radiation-induced illnesses are essential to our Nation’s preparedness and response capabilities.

On September 23, 2004, the Secretary of Homeland Security determined that radiological and nuclear agents present a material threat to the U.S. population sufficient to affect national security.

Acute Radiation Syndrome

Whole or significant partial-body exposure to high levels of radiation can cause Acute Radiation Syndrome (ARS), also known as radiation sickness.  ARS typically includes a range of physical signs and symptoms that reflect severe damage to specific parts of the body, including the bone marrow, the gastrointestinal tract, and the central nervous system.  The particular organs affected depend, in part, upon the radiation exposure level and the susceptibility of the individual organs.  At lower radiation levels, bone marrow effects occur that can lead to increased susceptibility to infection, anemia, and uncontrolled bleeding.  At slightly higher radiation levels, the gastrointestinal tract can be damaged, causing nausea, vomiting, and diarrhea, as well as the release of intestinal bacteria into the bloodstream that can further stress the depleted immune system.   At the highest radiation levels, the brain, spinal cord, and lungs can be affected.  These highest exposure levels are almost universally fatal, even with aggressive therapy.

Internal Contamination by Radioactive Particles

Radioactive particles can also be taken into the body through inhalation, ingestion, or wound contamination, and can be absorbed into organs such as bone, liver, or lymph nodes.  Once absorbed, the radioactive particles continue to emit ionizing radiation to the surrounding tissues, potentially leading to cell death, organ dysfunction, fibrosis, or malignancy. Rapid removal of these particles from the body is critical. 

Strategic National Stockpile Resources

HHS has made substantial progress in the acquisition of medical countermeasures for the Strategic National Stockpile (SNS).  These include the chelating agent Prussian Blue to protect against absorption of cesium-137 (a component of dirty bombs); potassium iodide (KI) tablets to block the absorption of radioactive iodide in the thyroid gland; growth factors that could be used to treat the hematopoietic effects of ARS; and large quantities of the general supplies that will be required to treat the complex array of medical problems following a nuclear attack, including antibiotics, anti-nausea drugs, and supplies to treat burn and blast injuries.

 Project BioShield

On July 21, 2004, President George W. Bush signed into law the Project BioShield Act of 2004 (Project BioShield) as part of a broader strategy to defend the United States against weapons of mass destruction.  The purpose of Project BioShield is to accelerate the research, development, purchase, and availability of effective medical countermeasures for the adverse health effects of chemical, biological, radiological, and nuclear (CBRN) agents.

In addressing radiological and nuclear threats, an interagency group of experts recommended the use of the Special Reserve Fund authorized under Project BioShield to acquire the following additional countermeasures for the Strategic National Stockpile (SNS):

• A liquid form of potassium iodide (KI) that can be taken more easily than tablets by children.  KI is a drug that blocks absorption of radioactive iodide in the thyroid gland.  The SNS maintains a supply of KI oral tablets. 
• Calcium- DTPA and Zinc-DTPA, two forms of a decorporation agent which help remove transuranic radioactive particles from the body.
• Treatments to address the neutropenia (relative lack of a type of white blood cells) associated with acute radiation syndrome.

The Secretaries of Health and Human Services and Homeland Security jointly recommended these acquisitions; the Director of the Office of Management and Budget approved the purchases under delegated authority from the President; and HHS implemented these acquisition programs.

Contracts have been awarded for 4.3 million bottles of liquid KI and for more than 480,000 doses of DTPA.  Delivery of the DTPA has been completed and delivery of the liquid formulation of KI is in progress. On May 30, 2007, HHS issued a Sources Sought notification for therapeutics applicable for the treatment of neutropenia resulting from exposure to ionizing radiation.  BARDA is currently reviewing responses received by the closing date of June 29, 2007.  HHS anticipates pursuing the initial acquisition of 100,000 treatment courses of a medical countermeasure against neutropenia arising as a consequence of ARS.