Deliberate Microbial Infection Research Reveals Limitations to Current Safety Protections of Healthy Human Subjects

Area of Science:

• Medical Ethics
• Infectious Disease Research
• Human Subject Research

Background:

• Microbial challenge experiments involve intentionally exposing healthy volunteers to pathogens.
• Such studies have a long history, dating back to World War II, and continue today.
• These experiments are conducted under evolving human subject research regulations.

Purpose of the Study:

• To identify the number of volunteers in historical and contemporary microbial challenge studies.
• To examine the associated risks and benefits of human microbial challenge experiments.
• To propose improvements in participant safety and ethical oversight.

Main Methods:

• Review of historical records and contemporary data on human microbial challenge studies.
• Analysis of participant numbers from late World War II to the present.
• Evaluation of ethical considerations, including risk assessment and duty of care.

Main Results:

• Approximately 40,000 volunteers were exposed to pathogens in studies from WWII to the early 2000s.
• An estimated 4,000 additional volunteers were experimentally infected between 2010 and the present.
• Identified concerns include the absence of maximum risk limits and potential inclusion of questionable benefits.

Conclusions:

• Human microbial challenge experiments require enhanced participant safety measures.
• The ethical review process for such studies needs strengthening, particularly regarding risk-benefit analysis.
• Further dialogue is needed on the ethical implications and participant risks in human experimentation.