Questions & Answers
Anthrax - Countering the Threat
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Anthrax Weapons -- The Threat

  1. Why is anthrax vaccination needed?
    Anthrax is highly lethal and relatively easy to produce in large quantities for use as a weapon. Anthrax spores are easily spread in the air over a large area and can be stored and remain viable for a long time. For this reason, anthrax may be the most important biological warfare threat facing U.S. forces. The intelligence community believes several countries currently have or are developing an offensive biological warfare capability using anthrax. However, given the ease with which anthrax can be produced, the threat could come from anywhere. For that reason, U.S. Forces may have little or no warning before an anthrax attack, which could be delivered by unconventional means. As a result, U.S. military forces around the world face a very real threat of a surprise anthrax attack. On February 24, 2004, CIA Director George Tenet told the Senate Select Intelligence Committee: "Although gaps in our understanding remain, we see al-Qaeda's program to produce anthrax as one of the most immediate terrorist CBRN [chemical, biological, radiological, nuclear] threats we are likely to face."

  2. Has any country ever used anthrax as a weapon?

    There is some evidence that the Japanese used anthrax as a biological weapon (BW) in China during World War II (Christopher GW, et al. Biological warfare: A historical perspective. JAMA 1997; 278 (Aug 6): 412-17).

    Since then, several countries are believed to have incorporated anthrax spores into biological weapons. Intelligence analysts believe that at least seven potential adversaries have an offensive BW capability to deliver anthrax -- twice the number of countries when the 1972 Biological and Toxin Weapons Convention (BTWC) took effect. The BTWC was designed to prohibit such activity.

    Iraq admitted to the United Nations in 1995 that it loaded anthrax spores into warheads during the Gulf War. In the post-cold war era, the former Soviet Union admitted to having enough anthrax on hand to kill every person on the planet several times over. The accidental aerosolized release of anthrax spores from a military microbiology facility in the former Soviet Union city of Sverdlovsk in 1979 resulted in at least 79 cases of anthrax infection and 68 human deaths and demonstrated the lethal potential of anthrax aerosols. Members of Aum Shinrikyo, the group responsible for the 1995 Tokyo sarin attack, reportedly experimented with biological agents in Japan before resorting to chemical agents. A lengthy article in the May 26, 1998, edition of the New York Times reported that members of Aum Shinrikyo released anthrax spores and botulinum toxin in Tokyo, Yokohama, and Yokosuka in 1990, targeting Japanese government and U.S. Navy facilities. Fortunately, no one was injured in these events.

    Anthrax spores have also been used as a weapon inside the United States by unknown terrorists in the Fall of 2001. The attack killed 5 people and infected at least 17 others.

  3. Has anthrax vaccine ever been used in the past? How often?
    Yes, since licensure in November 1970, anthrax vaccine has been administered to people at risk (both civilian and military) -- veterinarians, laboratory workers, and some people working with livestock for several decades. The manufacturer and FDA report that about 68,000 doses of anthrax vaccine were distributed between 1974 and 1989. The Army has purchased anthrax vaccine since its approval by the FDA in 1970, for use by about 1,500 at-risk laboratory workers. Anthrax vaccine was administered during the Gulf War to about 150,000 Service members, to protect U.S. forces against the threat of Iraq's biological weapons. The DoD vaccinated over 1.5 million DoD personnel with over 5.9 million doses since the beginning of the AVIP in March 1998.

  4. How are biological agents deployed?
    Biological agents can be dispersed in many ways, ranging from mailed envelopes, intentional human vectors, spray devices, bombs, to ballistic missiles. Biological agents are often hard to detect. Symptoms are delayed. Without preventive medical efforts, such as vaccination, the results can be devastating and widespread. A 1993 report by the U.S. Congressional Office of Technology Assessment estimated that between 130,000 and 3 million deaths could follow the aerosolized release of 100 kg of anthrax spores upwind of the Washington, DC area -- truly a weapon of mass destruction. An anthrax aerosol would be odorless, invisible, and capable of traveling many miles.

  5. Has the threat of biological warfare changed?
    The threat of biological warfare has been a risk to U.S. forces for many years. The threat of anthrax weapons in the hands of adversarial countries remains. But anthrax was used as a biological weapon in the United States in fall 2001 by unknown terrorists. Delivering anthrax was as simple as putting it in an envelope and dropping it in a mailbox. DoD analysts maintain an updated evaluation of the level of threat, adjusting the information as necessary to reflect the risk to U.S. operations. Assessment of the potential offensive biological threat facing American Service members indicates it is necessary to have a robust biological defense program today. The threat is real and the consequences are grave. On 16 October, 2006, Assistant Secretary of Defense for Health Affairs William Winkenwerder said, "...anthrax remains a deadly infection that's been used as a bioterrorism weapon against our own population. The threat environment and unpredictable nature of terrorism makes it necessary to include biological warfare defense as part of our force protection measures."

  6. Who is at greater risk from a biological attack? Soldiers? Sailors? Airmen? Marines? Front line? Rear area? Logistical units?
    Anthrax weapons have the potential to contaminate wide areas of the battlefield. It is difficult to determine who would be at a greater risk from a biological threat. All Service members meeting the criteria to receive the vaccine need to be protected, regardless of Service, specialty, or location within higher threat areas.

  7. What preparations have been made to respond to an anthrax release in a high-threat area?
    We are taking necessary steps to develop optimal protection against the threat of anthrax and other potential bio-weapon agents, including improved intelligence, detection, surveillance capabilities, protective clothing and equipment, new generation vaccines, and other medical countermeasures. In addition, we have stockpiled antibiotics in pre-positioned locations and medical personnel are better educated in the treatment of anthrax.

  8. If we vaccinate against anthrax, couldn't our adversaries just switch to a different biological weapon?
    If the DoD anthrax vaccination program causes adversaries to switch to a different weapon, it can be considered a success. Other biological weapons are less stable, less predictable, or less effective than anthrax weapons.

  9. Are vaccines being developed for other biological agents?
    Yes. As potential biological warfare threats are identified, DoD works with other government agencies and industry partners to develop medical countermeasures. Vaccines are being developed, whenever appropriate, for all validated biological threat agents. More information is provided in the specific Q & A section entitled -- Biological Warfare - Overview.