Anthrax vaccine will add to America's arsenal against bioterrorism

A company, based in Rockville, Maryland in the USA, with the help of government funding, has used the human genome to develop a vaccine that may give protection from anthrax.

The pharmaceutical company Human Genome Sciences Inc. (HGSI) received a federal contract last year from the Department of Heath and Human Services to the tune of $165 million and says it's anthrax vaccine, ABthrax, proved to be effective at protecting monkeys and rabbits who had inhaled anthrax spores.

HGSI says two animal studies demonstrated that a single dose of ABthrax improved anthrax survival in rats by up to 64% and the results are consistent with the results of previous studies.

In one of the animal studies, three groups of monkeys were exposed by inhalation to anthrax spores and treated with either ABthrax or placebo after they showed clinical signs of anthrax disease.

After 28 days, the study found that 64.3 percent of monkeys that received a single high dose of ABthrax survived; 50 percent of those that received a low dose also survived but none of the monkeys in the placebo control group survived.

Should the anthrax vaccine prove to be equally effective in humans, it will be the first vaccine sold by the company and the expectations are that the U.S. government will purchase it for their Strategic National Stockpile.

According to David Stump, executive vice president of research and development at HGSI they have completed the most challenging part of the scientific work.

ABthrax specifically targets anthrax toxins and represents a new way to tackle anthrax.

It seems that while antibiotics can kill the anthrax bacteria, they are not effective against the deadly toxins that the bacteria produce which are the real culprits in anthrax-related deaths.

When anthrax is inhaled people may not know they are infected until the toxins already are circulating in their blood, and it may then be too late for antibiotics alone to be effective; ABthrax targets anthrax toxins after they are released into the blood.

The company says that a second clinical trial of their vaccine in humans has shown promising results, with very few negative side effects being reported.

Anthrax infection is caused by a spore-forming bacterium which multiplies in the body and produces lethal toxins and most fatalities are caused by the irreversible effects of the anthrax toxins.

Anthrax spores are found in soil, are very tough and can live for many decades and maybe centuries and are known to occur on all continents except Antarctica.

Anthrax occurs most commonly in wild and domestic grass-eating mammals who ingest or breathe in the spores while eating grass.

Anthrax can be caught by humans when they are exposed to dead infected pigs, eat tissue from infected animals, or are exposed to a high density of anthrax spores from an animal's fur, hide, or wool.

Although anthrax cannot spread directly from human to human, anthrax spores can be transported by human clothing, shoes etc. and if a person dies of anthrax their body can be a very dangerous source of anthrax spores.

On the skin anthrax infection shows up as a boil-like skin lesion that eventually forms an ulcer with a black centre.

Gastrointestinal anthrax is most often caused by eating anthrax-infected meat and causes the vomiting of blood, severe diarrhea, acute inflammation of the intestinal tract, and loss of appetite; it can infect the intestines and the mouth and throat.

Once the bacteria invades the bowel system, it spreads through the bloodstream throughout the body, making even more toxins on the way; gastrointestinal infections are often fatal.

Respiratory infection appears as cold or flu-like symptoms for several days, followed by severe and often fatal respiratory collapse; this can rarely be treated, even if caught in early stages of infection.

Anthrax spores can be grown outside the body and used as a biological weapon.

The company says ABthrax offers a significant step forward in the treatment of inhalational anthrax, and could play an important role in strengthening America's arsenal against bioterrorism.

ABthrax received fast track designation in 2003 from the Food and Drug Administration.