Application of Single-use Bioreactors in Viral Vaccine Production Based on Microcarrier Culture

Vaccines have played a huge role in safeguarding national health and biological security.

Since the implementation of planned immunization in China, the incidence and mortality of infectious diseases have been effectively controlled. China has successfully eliminated smallpox, polio, and tetanus in pregnant women and newborns. The incidence and mortality of common infectious diseases in children, such as measles, mumps, rubella, pertussis, diphtheria, tetanus, epidemic encephalitis B, and epidemic cerebrospinal meningitis, have decreased by more than 95%. The infection rate of hepatitis B has dropped to less than 1%, achieving huge social and economic benefits.

Currently, there is a huge market demand for vaccines, including rabies vaccine, DPT vaccine, measles vaccine, etc. Improving the efficiency of vaccine production is the key to solving the problem of vaccine production capacity.

At present, a variety of viral vaccines are still produced using adherent cell culture methods. Vaccine companies typically use adherent cells and microcarriers to produce vaccines through parallel cultivation in multiple small stainless steel bioreactors. The stainless steel tank bioreactors require cleaning and sterilization, which significantly reduces production efficiency. At the same time, the parallel operation of multiple small bioreactors also significantly increases labor intensity and pollution risks. Single-use bioreactors have been widely used in the production of antibody drugs and have gradually entered the field of vaccine research and development and production in recent years. Therefore, the use of single-use bioreactors for large-scale vaccine production has become a trend in the industry.

BioLink has launched single-use bioreactors in 2021 and successfully assisted numerous vaccine clients in completing their scale-up production processes, accumulating extensive process expertise in viral vaccine projects utilizing microcarrier-based adherent cell culture.

CytoLinX® BR Single-use Bioreactors come standard with working volumes of 50 L, 200 L, 500 L, 1000 L, and 2000 L. Including a vessel, a controller and a temperature control unit (TCU), they are used for culturing mammalian cells, insect cells, and other low shear-rate needed cells.

CytoLinX® BR Single-use Bioreactors have the following characteristics:

• Developed based on the DCS architecture, its underlying logic is built with Siemens PCS 7, thereby covering the automation needs from research and development to production, and from a single unit to the entire upstream plant. Its automation logic complies with the ISA 88 control standard.

• The software design meets the requirements of GMP and 21 CFR Part 11. Meanwhile, in order to facilitate user operation, the CytoLinX® BR software interface is designed to be extremely simple, with all functions clearly visible at a glance, and can greatly meet the needs of customers.

• The automatic control system satisfies functions such as real-time data acquisition and recording, PID automatic control, online monitoring, and multi-parameter cascade control, and has stable performance in pH, DO, and temperature control.

• For more efficient mixing, BioLink has introduced a brand-new bottom dial design that can maintain a high linear KLa. It also provides solutions for consumables with micro spargers, medium spargers, macro spargers, and various combinations to meet the demanding cultivation needs of various cells.

Case Share

The experimental results of culturing Vero cells using Puredex® Cyto-1 microcarriers from BioLink in the CytoLinX® BR Single-use Bioreactors for the preparation of influenza virus are as follows:

Process flow: Seed cells are revived in the cell factory, transferred to a 50 L single-use reactor for seed expansion, and finally produced in a 200 L single-use bioreactor.

Adhesion of Vero cells:

The cell growth, metabolic data, and final yield of this experiment all met the expections, indicating that the CytoLinX® BR Single-use Bioreactors can achieve the same effect as traditional stainless steel reactors in the culture of adherent cells, while eliminating cumbersome steps such as cleaning and sterilization, which can significantly improve production efficiency.

Advantages of CytoLinX® BR Single-use Bioreactors in Adherent Cell Culture:

◆ Accurate control of parameters such as pH, DO, and temperature to ensure cell growth. The pH control accuracy can reach ±0.03, the dissolved oxygen control accuracy can reach ±3%, and the temperature control accuracy can reach ±0.1℃.

◆ High-transparency film with a viewing window for 50%-90% of the visible loading volume, convenient for observing the sedimentation and suspension of microcarriers.

◆ With our own mold and consumable production factory, we can flexibly customize special reaction bags for microcarrier culture, which facilitates medium exchange and microcarrier transfer during the culture process.