I think having a clinical background is a great advantage. It may not be a necessity depending on your roles. After college, I was working in a clinical research lab in a hospital as a Research Assistant (RA) for two years. I came in without any experience in clinical research. Since it was a very busy lab with lost of simultaneous research studies going on, we, RAs were responsible for most things mentioned in the lecture from creating flyers, contacting subjects, consent subjects (consent forms, HIPPA etc), scheduling (matching with doctors), run experiments and especially, know what to look for and who to ask questions/who can give you the correct answers.
That was the RA position, I think for a higher position such as study coordinators, PI, it’s more important to have a clinical background because there are so many little details, documentation, deadlines. My study coordinator came in at the same time I started working there and she started as an RA for 6 months to prepare to be a study coordinator.