In some cases it might not be possible to anticipate the inclusion of potential subjects with vulnerabilities until enrollment. Since the safeguards required by the particular vulnerability may not have been addressed in the protocol, involvement of such subjects requires careful consideration, a reassessment of the protocol, and possibly a review of the protocol by the IRB to determine if any revision is necessary before proceeding to enroll the vulnerable subjects. Certain vulnerable populations such as prisoners, minors, and pregnant women have specific regulatory requirements that preclude their inclusion until these requirements are met. Of course it is always preferable to anticipate the enrollment of vulnerable subjects and address the additional safeguards required during the protocol design phase.
If a current subject becomes vulnerable during the course of the study, and the vulnerability was not anticipated and therefore is not addressed in the protocol, it may be necessary to remove the subject from the study. The IRB should be contacted to review whether the subject may remain in the study (with or without modifications to the protocol) and if the protocol needs revision to address this issue as the study proceeds.