Efficacy of inactivated variant porcine epidemic diarrhea virus vaccines in growing pigs

Lee, Seung Heon; Yang, Dong-Kun; Kim, Ha-Hyun; Cho, In-Soo

Experimental vaccines were prepared by mixing BEI-inactivated PEDV QIAP1401-p70 with a commercial adjuvant according to the manufacturers' recommendations. The adjuvants used were Montanide IMS 1313 N VG PR (IMS 1313, Seppic, Paris, France), Montanide GEL (IMS gel), Montanide ISA 201 VG (ISA 201), and Montanide ISA 206 VG (ISA 206). ISA201 and ISA206 are oil-based multiphasic-emulsion adjuvants, and IMS1313 (nanoparticle-based) and IMSgel (synthetic polymer-based) are aqueous adjuvants. Vaccine formulations using IMS1313 and IMSgel were prepared by adding the adjuvants to BEI-inactivated viral fluid to final adjuvant concentrations of 30% and 10% (v/v), followed by vortexing at room temperature for 15 minutes. Vaccine formulations using ISA201 and ISA206 were prepared by emulsifying inactivated viral fluid with an equal volume of adjuvant using a homogenizer with a stirrer-propeller blade at 500 rpm for 10 minutes at 32°C in a water bath. After cooling at 20°C for 1 hour, formation of water/oil/water (W/O/W) multiple emulsions was confirmed by microscopy. All adjuvanted vaccines contained 0.01% of thimerosal to prevent growth of microorganisms, and were aseptically transferred to sterile vaccine vials and stored at 4°C before use.