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Antidote for Anthrax
The development of the human antibody known as ABthrax could be the answer for attacking the lethal toxins generated by anthrax. However, its high costs and early stage in experimental development stand in the way of predicting its effectiveness and future availability.
1. What are the limitations of the vaccine currently used to prevent anthrax?
-- The immunization is not immediately effective but takes several weeks after the first dosage. It requires several injections over a period of 18 months, and annual boosters to maintain effectiveness.
2. Is the treatment effective once the infection is present?
-- The use of antibiotics, the standard treatment for infection, is effective against the anthrax bacteria in the early stages, but not against the toxins they produce. Once the bacteria have entered the bloodstream, the lethal toxins produces cannot be treated by antibiotics. There are also anthrax strains that are resistant to antibiotics.
3. What advances have there been in preventing and treating anthrax infection?
-- Earlier this year the U.S. Food and Drug Administration approved experiments in humans of the ABthrax antibody, which has proven effective against anthrax toxins in experiments with animals.
4. How does ABthrax work?
-- The toxins produced by the anthrax bacteria have three components, with the "protective antigen" being the one that allows the infection to spread to the cellular level. ABthrax recognizes this antigen and neutralizes it, preventing the toxins from entering and killing the cells.
5. How long does ABthrax take to protect the patient?
-- Unlike the anthrax vaccine, the protection provided by a single dose of ABthrax is immediate, once adequate levels of the antibody in the blood are achieved, usually a rapid process.
6. What have the results been so far?
-- ABthrax has proven effective in preventing the lethal effects of anthrax infection in rabbits and primates. Currently, clinical trials are being conducted to assess safety, level of tolerance and pharmacology of ABthrax in healthy adults.
7. Why has the development of new anthrax treatments taken so long?
-- The delay is largely due to financial and time restraints. Human Genome Sciences, which created ABthrax, has asked for federal funds to continues its research, which could delay a new vaccine as approval is needed by the U.S. Senate. The tests on human subjects must also be completed.