Traditionally, bioethicists have frowned on pursuing studies in children that could otherwise be done in adults, because children are unable to provide valid consent. Given that the primary objective of the study is safety, and that a sample size of 3 (or, combining the two studies, 6) and a follow-up of less than a year is minimally meaningful in terms of projecting safety, many bioethicists would question the prudence of continuing the study in pediatric populations.
The third volunteer in the Moorfield study was not an adult. A report in Science magazine (2 May 2008) indicates that the Philadelphia team will test the agent next in an eight-year-old.
(photo credit: kiddocone 1998)