Vulnerable Populations in “Ethically Impossible” STD Research in Guatemala from 1946 to 1948

In 2011, the Presidential Commission for the Study of Bioethical Issues (Bioethics Commission) issued “Ethically Impossible” STD Research in Guatemala from 1946 to 1948. The report is the result of its ethical analysis aimed at uncovering the activities of U.S. Public Health Service personnel during studies conducted in Guatemala involving the intentional exposure of vulnerable populations to sexually transmitted diseases without their consent. Subjects of the experiments included prisoners, soldiers, patients in a state-run psychiatric hospital, and commercial sex workers.

These populations are especially vulnerable to harm in human subjects research because of their inability or limited ability fully and independently to protect their own interests. Federal regulations and multinational guidelines and codes recognize the need to provide additional safeguards to ensure that vulnerable persons  are adequately protected in research.1 The Bioethics Commission assessed the experiments conducted in the 1940s against standards of that time as well as contemporary standards and found that in both contexts the experiments involved gross ethical violations.

For guided reading and discussion questions about vulnerable populations in the U.S. Public Health Service STD research studies in Guatemala, see pages 15-19 in A Study Guide to “Ethically Impossible” STD Research in Guatemala from 1946 to 1948, available at


Download module here.

Download the Background module on vulnerable populations here.


Listen to "Episode 8: Ethically Impossible", an episode of Ethically Sound, a podcast of the Presidential Commission for the Study of Bioethical Issues.




1 For a list of regulations, codes, and guidelines that detail protections for vulnerable populations see the Vulnerable Populations Background module. The module is available at


Ethically Sound Episodes

The Bioethics Commission has launched a new podcast series entitled Ethically Sound.  

Each podcast is playable direct online from the link(s) below or from SoundCloud, iTunes or the Ethically Sound Playlist on Youtube.  Follow the hashtag #EthicallySound for launch announcements.

Safeguarding Children

Ethics and Ebola

Anticipate and Communicate

Privacy & Progress

Gray Matters

New Directions

Moral Science

Ethically Impossible

Bioethics for Every Generation

Charting a Path Forward

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