Plasmapheresis of Anthrax-Vaccinated Subjects for Production of Anthrax Immune Globulin

This protocol is a joint project of the National Institutes of Health, the Centers for Disease Control and the United States Army Medical Research Institute for Infectious Diseases. It is designed to collect plasma from healthy employees of the Department of Defense who have been vaccinated against anthrax. The collected plasma will be pooled to make an anthrax-fighting antibody solution called anthrax immune globulin intravenous (AIGIV). This solution will be used for: * Animal experiments to test its effectiveness in preventing the development of anthrax after inhalation exposure; * Treating people severely ill with anthrax who are not improving with standard antibiotic therapy; and * Treating people exposed to spores of the bacteria that cause anthrax to try to prevent development of the disease. Healthy volunteers between 18 and 65 years of age who have received at least four doses of the anthrax vaccine and who meet the criteria for blood donors may be eligible to participate in this study. Volunteers will be recruited from Department of Defense civilian and military employees. Candidates will be screened with an interview and blood tests. Participants will undergo the following procedures: * Have a health history screen for donating plasma * Measurement of heart rate, blood pressure and temperature * Fingerstick to check hemoglobin level * Blood tests for HIV, hepatitis B and C, syphilis and other infectious diseases * Blood test for anthrax antibody levels * Plasmapheresis to collect blood plasma (the liquid part of the blood) In plasmapheresis, whole blood is drawn through a needle placed in an arm vein. The blood flows into a cell separator machine, where it is spun to separate the plasma from the blood cells. The plasma is collected in a plastic bag in the machine, while the rest of the blood is returned to the donor through the needle in the arm. During the procedure, the donor is given a blood thinner called citrate to prevent the blood from clottin