OPEN ACCESS Jacobs Journal of Vaccines and Vaccination Research Article Comparison of the Mucosal Adjuvant Endocine™ with Two Well-Known Adjuvants: Cholera Toxin and Alum Tina Falkeborn 1* , Naomi Asahara 2 , Masayuki Hayashi 2 , Masaaki Arai 2 , Jorma Hinkula 1 and Anna-Karin Maltais 3 1 Department of Clinical and Experimental Medicine, Linköping University, Sweden 2 Advanced Medical Research Laboratory, Mitsubishi Tanabe Pharma Corporation, 1000 Kamoshida-cho, Aoba-ku, Yokohama, Kanagawa 227-0033, Japan 3 Eurocine Vaccines AB, Karolinska Institutet Science Park, Solna, Sweden *Corresponding author: Dr. Tina Falkeborn, Department of Clinical and Experimental Medicine, Linköping University, Sweden, Tel: +46 (0)10 103 7203; Email: tina.falkeborn@liu.se Received: 03-11-2015 Accepted: 05-02-2015 Published: Copyright: © 2015 Tina Cite this article: Falkeborn T. Comparison of the Mucosal Adjuvant Endocine™ with Two Well-Known Adjuvants: Cholera Toxin and Alum. J J Vaccine Vaccination. 2015, 1(2): 006. Abstract To enable efficient mucosal vaccination with split or subunit antigens, an adjuvant is often needed. To date, no mucosal adjuvants are approved for human use, however, there are a variety of mucosal adjuvants in development, including the lipo- some-based adjuvant Endocine™. The aim of this study was to evaluate split influenza antigens together with Endocine™ and in order to assess the potency of Endocine™, the induction of humoral immune responses were compared to those follow- ing influenza vaccination with cholera toxin (CT) or aluminum salt (alum). We show that Endocine™ significantly enhances influenza-specific immune responses in intranasally immunized mice compared to non-adjuvanted vaccine. Furthermore, vaccines adjuvanted with Endocine™ evoked comparable serum IgG and virus neutralizing (VN) antibody titers as nasal vac- cines adjuvanted with CT. Compared to parenteral vaccination with alum, Endocine™ triggered significantly higher mucosal and serum IgA titers, and similar VN titers. Taken together, these results support further development of Endocine™ as a mucosal adjuvant and as part of a nasal influenza vaccine candidate. Keywords: Mucosal Adjuvant; Nasal Immunization; Vaccine; Endocine; Influenza; Neutralizing Antibodies Abbreviations AFC: Antibody Forming Cell Alum: Aluminum Salt CT: Cholera Toxin CTA: Cholera Toxin A Subunit CTB: Cholera Toxin B Subunit HA: Hemagglutinin HIB: Haemophilus influenzae Type B I.M.: Intramuscular LT: Escherichia coli Heat-Labile Toxin MDCK: Madin-Darby Canine Kidney NALT: Nasal Associated Lymphoid Tissue VN: Virus Neutralizing