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Background: Existing methods for preparing influenza vaccines pose the greatest challenge against highly pandemic avian influenza H7N9 outbreak in the poultry and humans. Exploring a new strategy for manufacturing and delivering a safe and effective H7N9 vaccine is needed urgently. Results: An alternative approach is to develop an influenza H7N9 oral vaccine based on yeast display technology in a timely manner. Hemagglutinin (HA) of A/Anhui/1/2013 (AH-H7N9) is used as a model antigen and characterized its expression on the surface of Saccharomyces cerevisiae (S.cerevisiae) EBY 100. Mice administrated orally with S.cerevisiae EBY100/pYD5-HA produced significant titers of IgG antibody as well as significant amounts of cytokines IFN-γ and IL-4. Importantly, S.cerevisiae EBY100/pYD5-HA could provide effective immune protection against homologous A/ Anhui/1/2013 (AH-H7N9) virus challenge. Conclusions: Our findings suggest that platform based on yeast surface technology provides an alternative approach to prepare a promising influenza H7N9 oral vaccine candidate that can significantly shorten the preparedness period and result in effective protection against influenza A pandemic.

Background Helicobacter pylori (H. pylori) is a common human pathogenic bacterium that is associated with gastric diseases. The current leading clinical therapy is combination antibiotics, but this treatment has safety issues, especially the induction of drug resistance. Therefore, developing a safe and effective vaccine against H. pylori is one of the best alternatives. Objective To develop Saccharomyces cerevisiae (S. cerevisiae)‐based oral vaccines and then demonstrate the feasibility of this platform for preventing H. pylori infection in the absence of a mucosal adjuvant. Materials and Methods Saccharomyces cerevisiae (S. cerevisiae)‐based oral vaccines, including EBY100/pYD1‐UreB and EBY100/pYD1‐VacA, were generated and analyzed by Western blot, Immunofluorescence analysis, flow cytometric assay, and indirect enzyme‐link immunosorbent assay (ELISA). Further, antibody responses induced by oral administration of EBY100/pYD1‐UreB, EBY100/pYD1‐VacA, or EBY100/pYD1‐UreB + EBY100/pYD1‐VacA were measured in a mouse model. Lastly, the vaccinated mice were infected with H. pylori SS1, and colonization in the stomach were evaluated. Results Saccharomyces cerevisiae‐based H. pylori oral vaccines were successfully constructed. Mice orally administered with EBY100/pYD1‐UreB, EBY100/pYD1‐VacA, or EBY100/pYD1‐UreB + EBY100/pYD1‐VacA exhibited a significant humoral immune response as well as a mucosal immune response. Importantly, S. cerevisiae‐based oral vaccines could effectively reduce bacterial loads with statistical significance after H. pylori infection. Conclusions Our study shows that S. cerevisiae‐based platforms can serve as an alternative approach for the future development of promising bacterial oral vaccine candidates.

Background Existing methods for preparing influenza vaccines pose the greatest challenge against highly pandemic avian influenza H7N9 outbreak in the poultry and humans. Exploring a new strategy for manufacturing and delivering a safe and effective H7N9 vaccine is needed urgently. Results An alternative approach is to develop an influenza H7N9 oral vaccine based on yeast display technology in a timely manner. Hemagglutinin (HA) of A/Anhui/1/2013 (AH-H7N9) is used as a model antigen and characterized its expression on the surface of Saccharomyces cerevisiae (S.cerevisiae) EBY 100. Mice administrated orally with S.cerevisiae EBY100/pYD5-HA produced significant titers of IgG antibody as well as significant amounts of cytokines IFN-γ and IL-4. Importantly, S.cerevisiae EBY100/pYD5-HA could provide effective immune protection against homologous A/Anhui/1/2013 (AH-H7N9) virus challenge. Conclusions Our findings suggest that platform based on yeast surface technology provides an alternative approach to prepare a promising influenza H7N9 oral vaccine candidate that can significantly shorten the preparedness period and result in effective protection against influenza A pandemic. Keywords: S.cerevisiae EBY100/pYD5-HA, Yeast display technology, Influenza A pandemic.

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