Vandy’s premed acceptance rate is 66 percent. That is not encouraging for such a highly ranked private school. FWIW, ND and WashU, schools at Vandy’s level, claim an 80+ percent acceptance rate. .
https://as.vanderbilt.edu/hpao/documents/2014_Annual_Report.pdf
The counter argument is that the OP will probably not get to med school at either Pitt or Vandy, so Vandy might offer better non-med school opportunities than Pitt.