Prisoners are subject to informed consent, and for actual experiments they are actually given additional levels of scrutiny because of their status. Again, this is shit for the medical establishment to sort out, not political commentators on the internet.
https://www.hhs.gov/ohrp/regulations-and-policy/guidance/faq/prisoner-research/index.html
https://www.prisonlegalnews.org/news/2007/may/15/prisoners-have-right-to-informed-consent-and-to-refuse-medical-treatment/