The Declaration of Helsinki is recognised worldwide as a cornerstone of research ethics. Working in the wake of the Nazi doctors’ trials at Nuremberg, drafters of the Declaration set out to codify the obligations of physician-researchers to research participants. Its significance cannot be overstated. Indeed, it is cited in most major guidelines on research involving humans and in the regulations of over a dozen countries.Although it has undergone five revisions,1 and most recently incorporated language aimed at addressing concerns over research (...) carried out in resource-poor countries,2–5 the Declaration could go much farther in addressing the profoundly altered landscape of research with humans. Research involving humans is now a global enterprise and often involves participants from resource-poor countries. Rather than being carried out at single institutions by veteran researchers, many studies are now conducted at many locations—including sites that are not academic medical centres—by new and relatively inexperienced investigators. A growing number of projects involve novel agents, based on innovative work in genomics and proteomics. Increasingly, research is sponsored by the for-profit sector. National governments and professional organisations around the globe provide laws, regulations and standards for the conduct of research involving humans. Considerable scholarship also critiques and guides this endeavour.In light of the current effort of the World Medical Association to revise the Declaration, we offer ideas on how to re-conceive the concept of “vulnerability” and its links with the principle of justice and, in turn, redirect the attention of researchers towards those who might be so designated.In the research context, “vulnerability” is associated with an inability partly or totally to protect one’s own interests. Typically, conceptions of vulnerability centre upon characteristics associated with particular groups that …. (shrink)