Studies on preparation of inactivated vaccines from cell cultures of mink enteritis virus (MEV) and their immunity.

In this paper, superhigh reproductive rate strains of MEV with titre more than HA8192x or TCID50 log10(9.7) have been achieved both by cultivation in cell lines with different susceptibility to MEV and by isolating and identifying in field by the author. The systematic tests proved that S18 and L12 strains of MEV are the best strains for vaccine preparation. In this study, the best means for the tissue cultivation of MEV and the most advanced technological process for the production and detection of serum-free cell-cultured MEV fluids with super-high HA titre in batches in large quantities have been established for the first time. Optimum conditions for MEV inactivation were determined, and safe and effective inactivated vaccines with mineral oil or Al(OH)3 gel adjuvant were successfully prepared with serum-free cell-cultured MEV fluids. Both vaccines with different adjuvants can be manufactured in batches in large quantities and have been widely used all over China since 1986. The change laws of the immune response kinetics of the MEV vaccines have been determined by the tests, and the indexes and laboratory animal models for monitoring humoral immune efficiency and immune protective rate of parvovirus vaccines have been established for the first time. The manufacturing and monitoring operation rules of the MEV vaccines with different adjuvants have been laid down by the author.