has role immunizes against pathogen Classical swine fever virus vaccine in research role classical swine fever virus vaccine Classical swine fever virus E1 mutant vaccine Oliver He An N to A amino acid substitution was made in the N594 site of the E1 glycoprotein, resulting in attenuation of the virus in swine. This attenuated virus induced protection against challenge with wild type CSFV 3255 vaccine VIOLIN: https://violinet.org/vaxquery/vaccine_detail.php?c_vaccine_id=3255 Rebecca Racz