Medical scientists usually need a doctorate degree in biological science. Some medical scientists have medical degrees. Medical scientists typically complete courses in biology, chemistry, physics, engineering, mathematics, and computer science.
Status: Medical Student (Accepted) AMCAS states that it usually takes ~4-6 weeks for verification to go through, but looking at the verification trend right now here: http://forums.studentdoctor.net/threads/2014-2015-verification-thread.1076112/ I would say you're looking at 3-4 weeks from the time of submission.
Answer: Assuming that you have ready access to a Proofing Agent, your side of the verification process can be completed in about 10 minutes. Once your materials arrive at CDC, they will be processed on a first come, first served basis that is expected to take 1 or 2 business days.