During the global pandemic, in addition to the Covid-19 development, the development of vaccines is another focus of people’s attention. Scientific institutions around the world are stepping up their development of vaccines in order to contain the still-spreading coronavirus. It is known that more than 180 countries and regions have made commitments to join the “New Coronavirus Vaccine Implementation Plan”, covering 90% of the world’s population. At present, four types of COVID-19 vaccines have been granted emergency use authorization in various countries and regions, one of which is the recombinant adenovirus vector vaccine.
Adenovirus vector
The Adenovirus is the double-helical structure of DNA, and it is commonly used for gene vectors in vaccines and gene therapy by relevant genetic recombination operations.
Production process and solution of recombinant adenovirus coronavirus vaccine
The production of a recombinant adenovirus vector vaccine follows several processes, starting from cell culture, virus inoculation, amplification and virus fluid collection, to isolation, purification and vaccine preparation. The production process is shown in the below picture.
In accordance with the above production process, TRUKING provides a complete solution covering four processes, namely upstream culture process, downstream separation and purification process, buffer preparation process and product preparation.
Upstream suspension culture technology
HEK 293 cell line is used for recombinant vaccine production. The main advantage of this cell line is that it grows in suspension in cell culture, which is a simple process that can be directly scaled up.
The process of cell amplification scales up stage by stage from 50L, 200L to 1000L. TRUKING’s BR-series bioreactors with reasonable mixing design have good control of dissolved oxygen and CO2, minimizing the impact of physical cutting on cell growth (including speed) and realizing optimum culture effect and virus replication titer.
One of the problems in adenovirus production optimization is the cell density effect. For recombinant adenovirus vector vaccine, the titer of the virus is closely related to the cell viability, and the antigen quantity of the vaccine is obviously related to cell density. TRUKING BR-series bioreactors have a higher yield during HEK293 cell culture as it optimizes infection conditions, culture conditions and harvest time, The cell density after optimization is up to 1 × 107 cell/ml, 1012 VP, IU: VP < 100, and virus yield of single HEK293 is 5000 IU/cell.
TRUKING BR-series bioreactors
Downstream high-efficiency separation and purification technology
The virus solution harvested through upstream culture needs to be purified to meet three requirements: a) the purity of vaccine is more than 90% without polymer; b) the content of DNA and protein can meet the requirements of pharmacopeia; c) the original solution can be preserved stably without aggregation and degradation. In principle, the best purification process could achieve a high comprehensive yield with few purification steps.
The downstream purification process of recombinant vaccine includes lysis, clarification, ultrafiltration & concentration, two-step chromatography, ultrafiltration and sterilization filtration.
TRUKING chromatography systems
TRUKING chromatography column
TRUKING ultra-filtration system
TRUKING provides a complete solution for isolation and purification, including deep filtration system, auto-chromatography system, auto-chromatography column, auto-loading station, homogenate system, ultra-filtration system and anti-bacteria filtration system.
TRUKING chromatography systems (AutoPrep) have the following characteristics: a) stable and user-friendly control software that is developed on the same platform as the ultrafiltration system; b) components are modularized and flow path is purposely designed so that liquids flow from lower position to higher position to facilitate elimination of bubbles, and the dead area in 10L piping systems is lower than 100ml; c) none-welded pipelines eliminate risks like rusty and leakage valve feedback and other safety designs are in place; d) column efficiency has been validated to be better than that of international mainstream suppliers.
TRUKING automatic chromatography column adopting isobaric and uniform flow design, the column efficiency has been verified in practice and the distribution effect has been greatly improved. The VB12 color strip test intuitively simulates the distribution of the sample in the TRUKING automatic chromatography column. The color strips in the picture are evenly distributed, without diffusion and tailing, indicating that the distribution effect of the distributor is excellent. The efficiency test experiment intuitively illustrates the high performance of the equipment. It uses 90um particle size chromatography media for the column efficiency test. The column efficiency data is more than 7000. Under the same test conditions, the column efficiency of TRUKING automatic chromatography column is more than 20% better than that of internationally famous brands.
Column test
Multistage medium/buffer preparation system
According to workshop configuration and production schedule, TRUKING can calculate the volume, type and time of culture medium required for upstream culture and amplification, and the volume, and type of buffer solution required for downstream purification.
TRUKING can design medium preparation systems as per material calculation of production process, production schedule and actual factory layout.
TRUKING Preparation system
Case study: medium preparation system of TRUKING recombinant adenovirus vector vaccine project
Case study: Buffer preparation system of TRUKING recombinant adenovirus vector vaccine project
Conclusion
As adenovirus is a platform technology that can achieve high expression with high quality, it supports fast R&D and preparation of vaccines and various gene therapy drugs. TRUKING’s total solution developed for recombinant adenovirus vector vaccine and adenovirus vector gene therapy provides strong guarantee for production of Covid-19 vaccines and gene therapy drugs.
