If the protocol changes during the clinical trial, what do the subjects need to do?

The subjects should be informed about any changes in the protocol and asked for their consent before proceeding with the new procedures. Possible consequences of not informing subjects about protocol changes include a violation of ethical principles and a lack of transparency in the study results. Additionally, if the changes are significant or involve invasive procedures, it may lead to subject withdrawal from the study or loss of trust in the research institution.