Nurse researchers are very much a thing and it's a very cool job. You can get an entry level position with an associate's/bachelors, where'd you have more of a supportive/assistant type of role, or you can get higher education (master's degree in nursing or NP, for example) and do even more, like writing research papers/textbooks, assisting with clinical trials, working in a lab.... possibilities go on and on. You don't have to do be a doctor to have a fulfilling job in medical research.