During the global pandemic, in addition to the Covid-19 development, the development of vaccine 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 recombinant adenovirus vector vaccine.

Adenovirus vector

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, media preparation process and buffer preparation process.

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 bioreactor with reasonable mixing design has 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 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 bioreactor has 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.

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 pharmacopoeia; 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 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 system (AutoPrep) has 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 system is lower than 100ml; c) none-welded pipelines eliminate risks of rusty and leakage risk, and valve feedback and other safety designs are in place; d) column efficiency has been validated to be better than that of international mainstream suppliers.

VB12 ribbon test

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 and layout medium preparation system as per material calculation of production process, production schedule and actual factory layout.

Conclusion

As adenovirus is a platform technology that can achieve high expression with controllable 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.As adenovirus is a platform technology that can achieve high expression with controllable 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.