Vulnerable Populations and How We Protect Them in Research

45 CFR 46 is the set of HHS regulations governing the practice of human-subject research. It is made up of five subparts, and in 2018, Subpart A (also referred to as the Common Rule) was revised. One particular area of guidance that was modified is the HHS definition of vulnerable populations. Historically, vulnerable populations have represented those groups of people that are particularly at-risk of being taken advantage of and/or experiencing harm as a result of participation in human-subject research, and as such, HHS requires that IRBs be particularly sensitive to research protocols that utilize members of those vulnerable populations. The principal populations of concern include pregnant women, human fetuses, neonates, prisoners, minors (typically considered those under 18 years of age), individuals with impaired decision-making capacity, legally incompetent persons, and economically and/or educationally disadvantaged.

 Logically speaking, all of these make sense as at-risk groups. 

  • Pregnant women, fetuses and neonates should be protected because research – especially the biomedical kind – exposes both mother and child to complications that aren’t necessarily always foreseeable. 
  • Prisoners, legally incompetent persons, and individuals with impaired decision-making capacity must be protected because they are arguably more at-risk to being exploited/coerced into participating in research. 
    • Incarcerated individuals have dramatically diminished rights/abilities to self-govern
    • Individuals with impaired decision-making abilities – and those that are considered legally incompetent – may not be able to adequately assess the risk of participating in research, and thus be unable to make an informed decision about consenting to participate. 
  • Minors are often protected for similar reasons as those with impaired decision-making abilities. While they may not suffer from cognitive impairments or disabilities, the developing brain of a minor is not always capable of evaluating risk and providing adequate consent. 
  • And finally, those that are economically and/or educationally disadvantaged individuals are considered to be vulnerable populations because they may be more easily coerced into participation based on things like incentives for participating.

That last category is one of the newly added groups as a result of 2018 Common Rule revisions, and with this change comes a new set of considerations for researchers and IRBs alike: when so many human-subject research projects likely include participants that are either economically or educationally disadvantaged, how can risk be mitigated – especially when it comes to recruitment practices? These are the things that we like to raise awareness about through our VIRB consultations and educational materials. Vulnerable populations need advocates.

If you would like to learn more about this, what you can do to help spread the word about safe and responsible research ethics, or if you just want to have a conversation about the critical work of IRBs, please reach out at or hit us up on social media @viableinsights.

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