Manufacturing of Viral Vectors for Gene Therapy
BlogNovember 15, 2020

Viral vectors are an essential part of gene therapy treatments. They are essential for delivering corrected genetic information to faulty genes within affected cells, and are at the heart of the gene therapy process. At Andelyn Biosciences, we specialize in viral vector manufacturing for gene therapy, so learn more about viral vectors below or contact us now for more information.

What Are Viral Vectors?

Viral vectors are tools that are used to deliver genetic material to cells, and are commonly used for several purposes like gene therapy, vaccinations, and more. Basically, viral vectors are inert viruses that can carry corrected genetic material and deliver it to cells in the body.

Genetic material like DNA or mRNA cannot simply be introduced into the body. The primary reason for this is that both DNA and cell membranes have a negative electric charge, so they repel each other.

Viral vectors, then, are “vehicles” that can transport the genetic “cargo” of gene therapy into the vaccine. They are able to quickly enter the body, enter cells, release their genetic cargo, and then get the appropriate response from the cell. There are 4 basic types of viral vectors used in clinical trials:

  • Adenoviral – These vectors carry their genetic material in the form of DNA, and have the advantage of being able to deliver a lot of genome copies for each host cell.
  • Adeno-associated vectors (AAV) – These vectors also carry their cargo in DNA form, and can transduce both dividing and non-dividing cells. They have a smaller genetic capacity and do not integrate into the host genome.
  • Y-retroviral – Y-retroviral vectors carry their genetic material in the form of RNA. They use enzymes to create DNA copies of the RNA through reverse transcription.
  • Lentiviral – This is a subtype of retrovirus, pairing RNA with reverse transcriptase enzymes. Unlike normal retroviruses, though, lentiviruses can be used to integrate genetic information into non-dividing cells.

The Viral Vector Production Process

The production process for viral vectors is extremely complex and requires multiple phases, so we’ll just discuss a simplified overview of how it works now.

To begin, the materials needed to build the viral vector must be produced, including plasmids that incorporate helper-virus functions, as well as the therapeutic gene “cargo” and some other materials depending on the type of virus and production process. Then, the infectious viral vector will be produced and harvested in a complex process by combining these basic materials.

Once the viral vector is complete, cells will be transfected with it to infect them and generate more of the viral vector, which is harvested and stored and then is further processed for final use.

Viral Vector Platforms

There are a number of different viral vector platforms for producing viral vectors. The two we use the most commonly at Andelyn Biosciences are adherent platforms and suspension platforms. The proper viral vector platform depends on the type of viral vector, required yield, and a number of other factors.

Adherent: Adherent viral vector platforms use cell stacks and hyper stacks. These vertically-stacked platforms are scalable, ergonomic, and are a closed system which helps ensure the best results.

Suspension: Suspension platforms, which make use of a bioreactor, are also used at Andelyn Biosciences for AAVs. This is a highly-scalable method of production that minimizes potential biological contaminants.

Contact Andelyn Biosciences For Industry-Leading Viral Vector Manufacturing Services

As experts in gene therapy manufacturing, Andelyn Biosciences is here to help you manufacture high-quality AAVs and other viral vectors for gene therapy. For more information and to get started, contact us online or call us at (844) AAV-CDMO.