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

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

Although emulsified adjuvants are frequently used in vet-erinary vaccines, instead of aluminum hydroxide, because they induce long-term immunity [32] , improved adjuvants such as those based on nanoparticles or polymers are required. IMS1313 and IMSgel are aqueous adjuvants composed of nanoparticles and an immunostimulatory compound and synthetic polymer, respectively (https://www.seppic.com). According to the manufacturer, both adjuvants significantly enhance the strength and duration of the immune response and are suitable for a wide range of infectious agents. Indeed, the ability of both adjuvants to induce specific mucosal immunity against various pathogens in target animals has been assessed [33] [34] [35] . In this study, pigs that received the vaccines containing IMS1313 and IMSgel exhibited a strong serum PEDV-specific antibody response. In summary, a novel inactivated PEDV vaccine formulated with a W/O/W emulsion adjuvant was immunogenic and effective in growing pigs. Our findings support use of growing pigs as an alternative experimental model for assessment of the protective efficacy of inactivated PEDV vaccines in pregnant sows and neonatal piglets. Therefore, our results may be used to reduce the risk of failure in future clinical trials of PEDV vaccines. Maternally derived lactogenic immunity (IgG and IgA) plays an important role in protection of neonatal piglets against PEDV infection [20] . Thus, future studies should assess the effect of vaccinating sows with our novel inactivated PEDV vaccine on neonatal piglets.