Which group is not explicitly recognized as vulnerable under the Common Rule?

The group not explicitly recognized as vulnerable under the Common Rule is workers. The Common Rule outlines various populations considered vulnerable to coercion or undue influence, specifically highlighting children, elderly persons, and individuals with mental disabilities due to their specific circumstances which may impair their ability to make fully autonomous decisions in research settings.

While workers can face potential vulnerability in research contexts, particularly regarding their employment status and the influence it may exert on their participation, they are not classified as a vulnerable group in the same way that the other options are. The focus of the Common Rule is more on the inherent characteristics that might impede voluntary consent or pose additional risks in research rather than occupational status alone. Thus, the lack of explicit recognition for workers aligns with the intent to protect those with greater identifiable risks in research participation.