Enhancing expression of the classical swine fever virus glycoprotein E2 in yeast and its application to a blocking ELISA.

•Production of yeast-expressed CSFV E2 (yE2) is enhanced by optimizing the first codon.•N-terminal 190 residues of E2 are essential for an efficient neutralizing antibody response.•The blocking ELISA using yE2 and the anti-E2 MAb, 1B6, performed well when detecting antibody in infected pig sera.