The present invention relates to the field of animal health. Particularly, the present invention relates to a recombinant classical swine fever virus E2 protein comprising at least one mutation at the epitope specifically recognized by the 6B8 monoclonal antibody. Further, the present invention provides an immunogenic composition comprising the recombinant E2 protein of the present invention and the use of the immunogenic composition for preventing and/or treating diseases associated with CSFV in an animal. Moreover, the present invention provides a method and a kit for differentiating animals infected with CSFV from animals vaccinated with the immunogenic composition of the present invention. Furthermore, the present invention provides a method of producing the E2 protein.