[PERSON]  
1 Department of Energy and Materials Engineering, Dongguk University-Seoul, Seoul 04620, Korea; [EMAIL_ADDRESS]  
S.-C. [PERSON]  
1 Department of Energy and Materials Engineering, Dongguk University-Seoul, Seoul 04620, Korea; [EMAIL_ADDRESS]  
S.-C. [PERSON]  
1 Department of Energy and Materials Engineering, Dongguk University-Seoul, Seoul 04620, Korea; [EMAIL_ADDRESS]  
S.-C. [PERSON]  
1 Department of Energy and Materials Engineering, Dongguk University-Seoul, Seoul 04620, Korea; [EMAIL_ADDRESS]  
S.-C. [PERSON]  
1 Department of Energy and Materials Engineering, Dongguk University-Seoul, Seoul 04620, Korea; [EMAIL_ADDRESS]  
S.-C. [PERSON]  
1 Department of Chemistry and Medical Chemistry, College of Science and Technology, Yonsei University, Wonju, Gangwondo 26493, Korea; [EMAIL_ADDRESS]  
[PERSON]  
1 Department of Energy and Materials Engineering, Dongguk University-Seoul, Seoul 04620, Korea; [EMAIL_ADDRESS]  
[PERSON]. [PERSON]  
1 Department of Energy and Materials Engineering, Dongguk University-Seoul, Seoul 04620, Korea; [EMAIL_ADDRESS]  
[PERSON]. [PERSON]  
1 Department of Energy and Materials Engineering, Dongguk University-Seoul, Seoul 04620, Korea; sban0103@naver. devastating bacterial disease in olive flounder (_Paralichthys olivacues_). To treat bacterial infections in fish, aquaculturists usually administer antibiotics to the fish by mixing antibiotics in the fish species. This method is cost-effective and has high efficiency in producing healthy fish, [4] so it has been widely applied. However, there exist several problems inherent to the use of antibiotic feed at fish farms. It is not easy to administer an ideal dose of antibiotics, the Food and Agriculture Organization (FAO) of the United Nations has warned that antimicrobial residues in fish species could have an impact on human health [1]. [PERSON] et al. [5] reported in 2015 serious issues with remnants of antimicrobial substances in Bangladesh. In their research, high concentration of antimicrobial substances, such as amoxicillin and oxytetracycline, remained in climbing perch (_Anabus testudineus_) and shrimp species (_Penaeus_). In addition, extra-label use of antibiotics [6] can produce environmental and ecological problems that are detrimental to human health. The European Commission warned that antimicrobial residues can affect fish and humans. They also reported that antibiotic residues, such as amoxicillin and clarithromycin, are present in waste water or water used in agriculture, possibly contributing to bacterial disease in humans who use food created from these water resources. Consequently, resistance in bacteria can represent a potential risk to human health, and this is also a problem that has been noted and identified as an issue in many waterbodies in Europe [7]. The use of vaccinations is a powerful approach to solve the problems resulting from extra-label use of antibiotics. Several commercial fish vaccines have been developed [8] that can be administered to fish through injection and immersion [9; 10]. However, applying the vaccination through injection or immersion is fairly limiting in aquaculture systems, since it is a time and labor-intensive job. The ideal way would be to have oral administration of the fish vaccination considering the ease of administration, less stress to the fish, unlimited applications according to fish size, and economical aquaculture management. There have been limited attempts to develop oral fish vaccines. [PERSON] et al. [11] developed an attenuated oral vaccine strain of tilapia group B streptococci. [PERSON] et al. [12] tried to produce an oral vaccine utilizing _Lactococcus garvieae_ with chitosan/alginate ingredients. In most oral vaccine studies, the most important point noted is the stable storage of antigens before release in the intestine, which was the target organ [13]. According to [PERSON] et al. [14], the presence of a hostile stomach environment is the first barrier for orally delivered fish vaccines.