| Autor: |
Sung JC; Research Department, DreamTec Cytokines Limited, Hong Kong, China.; Oristry BioTech (HK) Limited, Hong Kong, China.; Meserna Therapeutic (HK) Limited, Hong Kong, China.; L&L Immunotherapy Company Limited, Hong Kong, China., Liu Y; Research Department, DreamTec Cytokines Limited, Hong Kong, China.; Meserna Therapeutic (HK) Limited, Hong Kong, China., Wu KC; Research Department, DreamTec Cytokines Limited, Hong Kong, China., Choi MC; Research Department, DreamTec Cytokines Limited, Hong Kong, China., Ma CH; Research Department, DreamTec Cytokines Limited, Hong Kong, China., Lin J; Research Department, DreamTec Cytokines Limited, Hong Kong, China.; L&L Immunotherapy Company Limited, Hong Kong, China., He EIC; Research Department, DreamTec Cytokines Limited, Hong Kong, China., Leung DY; Zentrogene Bioscience Laboratory Limited, Hong Kong, China.; Health Plus Laboratory Limited, Hong Kong, China., Sze ET; School of Science and Technology, Hong Kong Metropolitan University, Hong Kong, China., Hamied YK; Cipla Limited, Mumbai 400013, India., Lam DM; L&L Immunotherapy Company Limited, Hong Kong, China.; Torsten Wiesel International Research Institute, Sichuan University, Chengdu 610017, China., Kwong KW; Research Department, DreamTec Cytokines Limited, Hong Kong, China.; Oristry BioTech (HK) Limited, Hong Kong, China.; Meserna Therapeutic (HK) Limited, Hong Kong, China.; Cipla Limited, Mumbai 400013, India. |
| Abstrakt: |
Various types of vaccines, such as mRNA, adenovirus, and inactivated virus by injection, have been developed to prevent SARS-CoV-2 infection. Although some of them have already been approved under the COVID-19 pandemic, various drawbacks, including severe side effects and the requirement for sub-zero temperature storage, may hinder their applications. Bacillus subtilis ( B. subtilis ) is generally recognized as a safe and endotoxin-free Gram-positive bacterium that has been extensively employed as a host for the expression of recombinant proteins. Its dormant spores are extraordinarily resistant to the harsh environment in the gastrointestinal tract. This feature makes it an ideal carrier for oral administration in resisting this acidic environment and for release in the intestine. In this study, an engineered B. subtilis spore expressing the SARS-CoV-2 spike protein receptor binding domain (sRBD) on the spore surface was developed. In a pilot test, no adverse health event was observed in either mice or healthy human volunteers after three oral courses of B. subtilis spores. Significant increases in neutralizing antibody against sRBD, in both mice and human volunteers, after oral administration were also found. These findings may enable the further clinical developments of B. subtilis spores as an oral vaccine candidate against COVID-19 in the future. |
