Final answer:
When a human subject involved in ongoing research becomes a prisoner, the researcher must notify the IRB and ensure the subject's safety. The subject's health is of concern, and research activities may continue with additional protections.
Step-by-step explanation:
When a human subject involved in ongoing research becomes a prisoner during the course of the study, the researcher must promptly notify the Institutional Review Board (IRB) and take appropriate steps to ensure the subject's safety. In this situation, the subject's health is a concern rather than ongoing data collection, but research activities may still continue, including the use of the study drug. However, the medical aspects need to be directly addressed and additional protections are required to minimize the risk of harm. The researcher plays an active role in protecting the subject's health and seeking guidance from the IRB for appropriate actions.