Controversy Surrounds Anthrax Vaccine

Medically Reviewed by Charlotte E. Grayson Mathis, MD on November 08, 2001
From the WebMD Archives

Nov. 8, 2001 -- A controversial vaccine with a history ofmanufacturing problems is the first line of defense in the war againstweaponized anthrax. Is the anthrax vaccine safe? Is it effective? The answerdepends on whom you ask.

Critics say the vaccine has been proven neither safe noreffective and may even be the cause of the mysterious group of ailments knownas Gulf War syndrome that afflicts some soldiers. Government officials counterthat there is no scientific evidence to back up that claim. They note that morethan 500,000 U.S. troops have received anthrax vaccinations during the pastthree years, with less than 0.5% reporting even minor adverse reactions.

Supporters of the military's suspended program to vaccinate its2.4 million active duty personnel and reservists say 18 separate studies showthat the anthrax vaccine is safe. But an outspoken opponent of the programcites several others suggesting that short-term side effects are far morecommon than have been reported. Maine doctor Meryl Nass, MD, has studiedanthrax for the past 13 years, and testified before Congress two years ago onthe vaccine's safety.

"There are no data at all on long-term reactions," Nasstells WebMD. "The only long-term information we have is anecdotal. But themany, many anecdotal reports I have heard over the years suggest to me thatlong-term problems are common in those who receive this vaccine."

John F. Modlin, MD, who leads the government's AdvisoryCommittee on Immunization Practices, agrees that there are still unansweredquestions about the anthrax vaccine. Last December, the committee issued areport that, among other things, called for more studies into its safety.

At the time, the group did not recommend the routinevaccination of emergency workers and other so-called first responders who mightbe occupationally exposed in a bioterrorist attack. The committee wrote that,"at present, the target population for a bioterrorist attack of (anthrax)cannot be predetermined, and the risk of exposure cannot becalculated."

Modlin tells WebMD that the assessment of risk a year ago wasvery different from what it is today. He says the committee will revisit itsrecommendations on who should receive the vaccine. A CDC spokesperson says thatmeeting should take place soon.

"It may be that there is a wider group of people judged tobe at occupational risk who we will recommend get the vaccine," Modlinsays. "I don't want to speculate right now on who that would be. That iswhat we have to work out."

Manufacturing Woes

This week, the military announced that it will be givinganthrax vaccinations only to troops considered most at risk of a bioterrorismattack because its supply of vaccine is limited. And though health officialsrecently said criminal investigators, decontamination crews, and others workingclosely with anthrax investigations should be vaccinated, it is unclear whetherthat is happening.

No one is quite sure how much anthrax vaccine is available orwill be available in the near future. That is because the FDA forced the soleU.S. manufacturer of anthrax vaccine to stop distribution two years ago afteran inspection found 30 violations at the manufacturing plant. Those violationsincluded vaccine safety and sterility problems.

BioPort Corp. of Lansing, Mich., has actually been making andstockpiling the vaccine again for over a year, but the reserves can not be usedor distributed until it passes another FDA inspection. That could be as earlyas Thanksgiving, but there are no guarantees, officials say.

If BioPort does pass inspection, some 5.4 million doses ofanthrax vaccine will be available for immediate distribution, Health and HumanServices secretary Tommy G. Thompson said late last week. But Rep. ChristopherShays, R-Conn., who has held hearings on the anthrax vaccine, says it isunclear if the stockpiled doses are safe.

Military Discord

The anthrax vaccine used in the United States was developedduring the 1950s and '60s and was licensed by the FDA in 1970. It is given as aseries of six injections over 18 months and poses no risk of developing thedisease because it is a killed vaccine.

Critics say there is no guarantee that the vaccine is effectiveagainst all strains of anthrax and that terrorists could conceivablymanufacture vaccine-resistant strains to use as weapons. The only human studyever done in the U.S. evaluated the vaccine during an outbreak of anthrax amongNew Hampshire mill workers 40 years ago. It was found to be 93% effective inworkers who got the vaccine, and studies in monkeys have shown similar rates ofprotection.

The main controversy surrounding the vaccine involves itssafety, not effectiveness. Hundreds of military personnel have faceddisciplinary actions since 1998 for refusing to take it, and about 50 have beencourt-martialed. The Government Accounting Office recently reported that asignificant number of reserve and National Guard pilots have left the militaryrather than take the anthrax shots.

Nass says she has been contacted by many people in the militarywho blame the vaccine for chronic health problems. Most have been women, andmost complaints have been symptoms such as chronic fatigue and pain, which arethe same symptoms of several chronic diseases common in women such asfibromyalgia and lupus. There is no direct evidence that these symptoms arelinked to the vaccine, however.

"The best information we have suggests that this vaccine issafe," Modlin says. "But a vaccine is only one means of protectingone's self from disease, and in this case there are other equally or moreimportant things we can do. A vaccine is never going to be the answer to theproblem. It is only one measure we can take to address it."