The adjuvant is a substance used in combination with an antigen to assist in antigen presentation and enhance the immune response. Traditionally, only aluminium adjuvants have been widely used in vaccine development. Since the 21st century, novel adjuvants have gradually become widely used in the vaccine industry to create vaccine products that can stimulate more and broader immune responses to deal with major diseases with a heavy burden. According to Frost Sullivan, as of July 6, 2021, only five novel adjuvants -- AS01, AS03, AS04, CpG1018 and MF59 -- had been in the public domain for more than 20 years. With this platform, Recbio is one of the few companies that can develop new adjuvants that match all of the FDA approved adjuvants. Thanks to this capability, the company is not dependent on any specific adjuvant supplier. The platform also enables the company to discover and deploy novel adjuvants in the next generation of vaccine candidates.
Based on interdisciplinary research, The Protein engineering platform of Recbio uses a structure-based approach to immunogen design to provide antigen optimization solutions for innovative vaccine development. The platform enables rapid discovery and identification of potential antigens to determine the structural basis of antigenicity, understand the mechanisms of immune protection and guide rational immunogen design, which is a key step for the company to develop vaccines. In addition, the company's protein engineering platform uses a variety of expression systems, including E. coli, Hanson's yeast, baculovirus and CHO cell expression systems. Through this diverse expression approach, the company is able to select and apply the most appropriate expression system for vaccine development. The platform enables the company to rapidly advance the development of vaccine candidates for COVID-19 and HPV.
To elucidate the immune protection mechanism of emerging and re-emerging infectious diseases, immunoevaluation is a key step in the discovery and development of innovative vaccines. Through this platform, companies can select the best combination of antigens and adjuvants to improve immunogenicity. Immunoevaluation involves many subjects such as immunology, biology, molecular biology and clinical chemistry. The core scientific team of the company started to build the immune evaluation platform as early as 2004, and Recbio is one of the first teams to have this platform in China. Through this platform, the company became one of the first companies in China to be able to conduct fake virus neutralization, ELISPOT and ICS tests, which have been used in our vaccine candidate development, demonstrating the company's strong R&D capabilities.
Based on new adjuvant, mRNA design, modification and synthesis, delivery and other underlying technologies with global independent intellectual property rights, the company will efficiently design and develop a new generation of mRNA vaccines with strong accessibility "From the bottom, from the source", and plan to gradually expand to other major infectious disease vaccines and tumor therapeutic vaccines.
R520A is an mRNA COVID-19 vaccine specifically targeting the Omicron variant developed by Wuhan Recogen Biotechnology Co., Ltd. (武漢瑞科吉生物技術有限公司), a subsidiary of the Company. R520A adopts a self-developed lyophilization technology that can effectively sustain the physiochemical properties and bioactivity of mRNA-LNP and achieve long-term storage at 2℃–8℃. In the pre-clinical studies, the level of neutralizing antibody titers against Omicron variant increased to a high level of 4,758 and it can also induce neutralization response against Delta variant, indicating its promising immunogenicity profile. The relevant research results have been posted on the preprint server, bioRxiv.