**5.3 VAXIJEN 2.0™**

VaxiJen is the first server for the prediction of protective antigens, antigens tumor, and vaccine subunits. It is also a grade-free bioinformatics tool first for silico immunogen identification. VaxiJen uses the Z-scale Wold to explain the Physicochemical properties of the primary amino acids building protein. The Amino acids are tested, converting the derived string to a uniform vector with auto cross-covariance (ACC). The next step is to select the relevant variable with a genetic algorithm (G.A.) or gradual regression and classify protein as a protective or non-antigen antigen by discriminant analysis least-squares based (PLS). Initially, Algorithm files are trained to identify the protective immunogens of bacteria. A model for immunogens viruses and tumors was then included, and VaxiJen was developed to provide access free to the model. The latest version of VaxiJen (VaxiJen 2.0) also includes a model for identifying parasitic and fungal immunogens [15]. Vaxijen used to validate the results of the epitope sequences found from the IEDB whether they are immunogenic or not.
