How do you balance the individual risk of testing an anthrax vaccine for children against the societal good of having the vaccine on hand in case of an anthrax terrorist attack?
This morning, the Presidential Commission for the Study of Bioethical Issues explored how researchers tackled this ethical dilemma in 2002. Months after 9/11, worried about the threat of a smallpox terrorist attack, members of the Internal Review Board at Harbor-University of California at Los Angeles (Harbor-UCLA) Medical Center looked at whether to test a diluted form of the vaccine Dryvax to protect children. Production of Dryvax had ended and supplies had dwindled. Harbor-UCLA staff wanted to see if diluting the vaccine (which would extend the available supply) was a safe and effective way of addressing the threat of a smallpox attack for children. An earlier study determined that using a diluted vaccine was safe in adults.
Neal Halsey, M.D., Professor of International Health and the Johns Hopkins Bloomberg School of Public Health, reviewed the history of the pediatric study of the Dryvax vaccine for the Commission. The Pediatric Rule, he noted, is that you must study vaccines and drugs in children when there is anticipated use. “But,” he said, “In these situations, how do you estimate this use?”
David Resnik, J.D., Ph.D., Bioethicist and IRB Chair for the National Institute for Environmental Health Sciences, discussed the concept of minimal risk and the National Institutes of Health’s definition: as a probability and magnitude of harm not greater than that encountered in daily life. But he added that applying this definition was difficult in practice; even the act of drawing blood was not universally recognized as meeting minimal risk standards.
Commission member John Arras, of the University of Virginia, discussed how the Commission has received conflicting information on whether testing an anthrax vaccine for children represented a minimal risk.
Halsey replied that “There’s a zone that exists between somewhat greater than minimal risk and the risk posed by the smallpox vaccine. There is no adequate gradation that comes into play. Until the vaccines have been studied and studied widely, you don’t know the risk.”
Ruth Berkelman, M.D., Rollins Professor and Director of the Emory University Center for Public Health Preparedness and Research, explained to the Commission that both societal and individual risk must be considered.
“Protecting the public health is an essential government responsibility,” she said. “Public health is used to dealing with scant data. But there is a huge difference between minimal data and no data. In the absence of data, the government’s response can be confused.”
In the case of Dryvax, which had potentially severe complications, the debate on whether to begin studying the safety of a diluted vaccine in clinical trials with children lasted until early 2003 when the Secretary of Health and Human Services and Food and Drug Administration Commissioner agreed to end the initiative.
“Bioterrorism preparedness plans have evolved such that, under current plans, the potential to use diluted Dryvax in children will no longer exist,” the two officials said in a joint statement.
All participants in this morning’s conversation acknowledged that the smallpox vaccine presented serious health risks. But the risks posed by the anthrax vaccine to children proved harder to define, and in the end, the Dryvax story did not offer a bright line of where to balance the risk.