Government may offer an experimental treatment for anthrax should another attack occur

Monday, January 7th 2002, 12:00 am
By: News On 6

WASHINGTON (AP) _ If anthrax strikes another American, the government may offer patients an experimental treatment: a protective protein culled from the blood of soldiers who received the anthrax vaccine.

This immune globulin is being added to the nation's bioterrorism treatment stockpile, a scientist with the Centers for Disease Control and Prevention said Monday.

IG treatment for anthrax would be experimental and require the consent of the Food and Drug Administration, cautioned CDC anthrax expert Dr. Bradley Perkins. But the therapy has worked with other diseases and discussions with FDA are far enough along that ``we could rush this through'' if anyone else comes down with anthrax and needs it, he said.

IG wouldn't replace antibiotics as treatment for anthrax. But antibiotics kill only the anthrax bacteria, not the cell-killing toxin those bacteria churn out in people's blood. The hope is that IG would neutralize the toxin, Perkins said.

New anthrax treatments took on urgency with this fall's attacks-by-mail, which caused 18 confirmed cases of infection. Five people have died, and the culprit has not been found.

Thousands exposed during the attacks have taken two months of antibiotics to prevent infection, and now are being offered either anthrax vaccine or 40 extra days of drugs in case any anthrax still lurks in their lungs. Some 1,168 people have opted for extra drugs and 130 for the vaccine, CDC officials said Monday.

Perkins' comments about IG came at a scientific meeting to evaluate a separate issue: a new CDC study of pre-exposure anthrax vaccination that aims to prove whether fewer doses given in a different way would be as effective and less uncomfortable than today's method.

The Pentagon hopes to inoculate millions of troops against an anthrax attack and already has vaccinated 500,000. Soldiers are supposed to get six shots over 18 months, plus an annual booster dose.

The vaccine has been used for decades and most experts consider it very safe. But it has caused controversy as some soldiers complained the shots could be linked to such long-term disorders as chronic fatigue. The CDC soon plans a survey of military personnel to learn how those fears can be lessened.

For the new inoculation study, the CDC plans this month to begin recruiting 1,500 civilians to test whether as few as three shots and an every-three-years booster would work. Some people will get varying doses of vaccine, while others will get dummy shots.

``Probably a three-dose regimen is going to be effective,'' Perkins said, who called the study ``a linchpin'' of congressionally mandated research into ways to make anthrax vaccination easier and safer.

The study also will test if the current under-the-skin shot causes fewer injection-site side effects, such as swelling and skin nodules, if given in the muscle like many other vaccines.

The study will be run at five medical centers: Emory University; University of Alabama, Birmingham; Baylor College of Medicine; the Mayo Clinic; and Walter Reed Army Medical Center.

How will researchers tell if the experimental inoculation method works? After all, it's unethical to expose people to anthrax to see if a vaccine really protects.

First, researchers will measure levels of various immune markers, including antibodies, in the recipients' blood, comparing them to levels found when people get the FDA-approved six-shot vaccine regimen.

Then they will compare the results to a monkey study. Monkeys given various vaccine doses will be exposed to potentially lethal anthrax doses. The amount of antibodies and other immunity markers the monkey survivors bear in their blood should provide a good clue to how protected people with similar blood levels will be if they encounter anthrax, CDC researcher Jairam Lingappa told a meeting of the National Academy of Sciences.

Congress ordered the academy to oversee the CDC's study and ensure it is as scientifically rigorous as possible.