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Anthrax vaccine trial meets bioethicists

An anthrax vaccine would protect civilians from the long-term effects of a bioterrorist attack. But there’s no telling how children would react to the shots.

To assess the ethics of a trial, in which kids would get an anthrax vaccine unlikely to ever be necessary, a federal committee met today in Washington DC.

“The chance that we would have a widespread outbreak of anthrax are relatively low, but if anthrax were weaponized, it would be catastrophic,” explains Larry Gostin, of the O’Neill Institute Center on Public Health Law and Human Rights in Washington DC. “From a public-health perspective, it’s right to think about the best way to prevent these hazards.”

The Presidential Commission for the Study of Bioethical Issues is expected to finalize their decision by early next year. Their task follows a vote in favour of a paediatric anthrax vaccine trial by the US National Biodefense Science Board in October, who in turn had been asked for an opinion by the US Department of Health and Human Services (HHS).

Momentum for a trial began after the worrisome results of a doomsday “exercise” designed to test how the country would react to an immense release of anthrax spores in San Francisco. The project, called Dark Zephyr, found that 7.6 million people — including 1.7 million individuals under age 18 — would need to be vaccinated.

Regardless of a clinical trial, teens and children would immunized if disaster struck because the shots have proven safe in some 1.2 million vaccinated adults in the military, says Major General John Parker, the chair of the National Biodefense Science Board. Among other things, a trial would let clinicians know how much vaccine to give, he says.

Children complicate clinical trials, ethically speaking, because participants ought to fully grasp the risks and purposes of a trial before enrolling, and kids often do not. Other concerns voiced at the meeting included the fact that a paediatric anthrax vaccine trial is unlikely yield direct benefits to participants because there’s little chance of an anthrax attack, and an even smaller chance of an attack near the locale where the trial ensued.

Amy Gutmann, the chair of the bioethical issues commission, says that a strong case for the study would be made  “if the community that’s most supportive of moving this forward would volunteer their own children for the study”. Parker responded to the comment: “There are people in our population [the armed forces] that would like their family immunized.”

Some experts weren’t swayed by the putative pay-off of a trial. Nicola Klein, co-director at the Kaiser Permanente Vaccine Study Center, says that she’s not convinced that anthrax is now a credible threat. And Robert “Skip” Nelson, a paediatric ethicist at the US Food and Drug Administration, questions the need for a pre-emptive trial as opposed to one after a catastrophe hits. After all, people would take 60 days of antibiotics to ward off the immediate effects of an anthrax attack, whereas the vaccine would provide protection for future exposures. “If the argument is that a pre-event study is better,” he says, “I need to know the science behind why that is.”

HHS Secretary Kathleen Sebelius illustrated the gravity of the dilemma by voicing her appreciation for the bioethics commission and the experts at the meeting. “Your work is critically important to the 300 million people or so who are not in the room today,” she says. “And I thank you on their behalf because your work affects their lives whether they know it or not.”


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