After Helsinki: unresolved issues in international research.

Following a long process of revision, a new version of the Declaration of Helsinki was approved by the World Medical Association in 2000. Two provisions of the Declaration address ongoing international controversies regarding research sponsored by industrialized countries and conducted in developing countries. Despite the issuance of the final version of the Declaration, opponents remain locked in debate. Moreover, the Declaration remained silent on other prominent controversies concerning international research. An analysis of these current controversies reveals reasons why they are not likely to be readily resolved, despite apparent agreement by opponents on overarching ethical principles.