  We consider the $(2+1)$ flavor Polyakov Quark Meson Model and study the
effect of including fermion vacuum fluctuations on the thermodynamics and phase
diagram. The resulting model predictions are compared to the recent QCD lattice
simulations by the HotQCD and Wuppertal-Budapest collaborations. The variation
of the thermodynamic quantities across the phase transition region becomes
smoother. This results in better agreement with the lattice data. Depending on
the value of the mass of the sigma meson, including the vacuum term results in
either pushing the critical end point into higher values of the chemical
potential or excluding the possibility of a critical end point altogether.
