Most people would suggest otherwise, but I found taking Immunology was immensely helpful for the MCAT. I've taken several advanced coursework this past year (as post-bac): Molecular Genetics, Microbiology, Immunology, Parasitology, Anatomy & Physiology I and II, and (standard) Genetics. There always seems to be atleast one passage on Immunology for every MCAT and is probably the one most people struggle with, so taking the class would put you at a significant advantage. At this point though, it's kinda of meaningless because the MCAT is changing. Based on the trial section I took, the new MCAT is a whole different ball game than what we're use to. Definitely focus on taking required courses first before anything else (including sociology, psychology, and biochemistry). I wouldn't really recommend taking any other upper level class (aside from A&P) for medical school since most of what you learn would probably be forgotten by the time you get there. Immunology, Parasitology, Microbiology are all part of the second year curriculum in most medical schools.
