The invention relates to a marker vaccine for prophylactic treatment of classical swine fever comprising modified live attenuated classical swine fever virus. The viral amino acid sequence of the TAV-epitope of the E2 protein comprises a different sequence from that of a wild-type classical swine fever virus. The invention relates to pharmaceutical compositions of the marker vaccine. The invention also relates to a method of manufacturing marker vaccines for prevention of classical swine fever using selective antibody pressure.
