Medical experiments involving intentionally infecting people with bacteria, viruses, and parasites are surprisingly common. And they are becoming more common worldwide, particularly in developing countries.
The ultimate aim of these “human challenge studies” is usually to test potential new vaccines.
However, because of the risks involved, this kind of research raises difficult ethical questions. For example, who should be infected? And which pathogens would be too dangerous to use?
- Human Challenge Trial workshop: Focus on the quality requirements for challenge agents
- Expert voices and equal partnerships: establishing Controlled Human Infection Models (CHIMs) in Vietnam - Wellcome Open Research, Kestelyn et al 
- REQUEST FOR PROPOSAL: Regulatory guidelines for the manufacture of human challenge agents (updated deadline: 27 Sept 2019)