What are viral vectors?

iosBio’s vaccines and therapeutics use viral vector technology

This is where a harmless virus (in the case of OraPro, a non-replicating adenovirus) is genetically engineered to carry some of the genetic material from the pathogen, e.g. Covid-19, against which immunity is created. When administered, the viral vector vaccine causes the body’s own cells to manufacture proteins from the target pathogen, provoking an immune response and stimulating the production of antibodies and T-cells. This means that when the body is exposed to the real pathogen, it already has the tools it needs to combat the infection.

iosBio’s technology is unique in that it uses our proprietary thermal stability excipients to deliver a viral vector vaccine that is thermally stable at room temperature. This not only transforms the distribution process by removing the cold chain, it also enables fast and easy oral delivery, removing the healthcare professional and the needle from the administration process.

This platform is OraPro.

Why use viral vectors?

Viral vector vaccines don't contain antigens, but instead use the body's own cells to produce them.

They do this by using a modified virus (the vector) to deliver the genetic code for an antigen (e.g. the Covid-19 spike proteins) into human cells. By infecting cells and instructing them to produce safe non-replicating antigens, which then trigger an immune response, the vaccine mimics what happens during a natural infection without risk of an actual infection.

This immune response includes both B cells and T cells. B cells fight bacteria and viruses by producing antibodies specific to each pathogen. Antibodies lock onto the surface of an invading bacteria or virus and mark it for destruction by immune cells. T cells examine the proteins expressed on the surfaces of cells and destroy cells that have been infected by a foreign pathogen.

Generally speaking, viral vectors have a better safety profile than many live-attenuated virus vaccines and are more immunogenic than inactivated/killed virus vaccines.

One significant problem with existing viral vector technology is ‘anti-vector immunity’, whereby the body recognizes the harmless viral vector and mounts an immune response against it, limiting the efficacy of the vaccine. This means that it’s not always possible to deliver booster doses or an adapted vaccine tweaked for mutations using the same viral vector.

iosBio’s oral viral vector technology overcomes this problem by delivering the vector to the mucosal cells under the tongue or in the gastrointestinal tract, thereby avoiding the anti-vector immunity created by injectable vectors.

The Technology

The vaccine is freeze-dried and encased in an enteric capsule. This allows it to travel through the stomach, a highly acidic environment with a temperature of 37C, with no loss of efficacy. Viral vectors are highly thermally unstable and normally have to be frozen at -80C. Without OraPro technology, this effectively means that oral delivery through the stomach at 37C would not be possible.

Once the capsule passes into the small intestine, an alkaline environment, the capsule dissolves. The viral vector vaccine within delivers the pathogen DNA to the mucosal cells. The antigen is then expressed within cells and presented to mucosal associated lymphoid tissue, eliciting a mucosal and systemic immune response.

This not only transforms the distribution process by removing the cold chain, it also enables fast and easy oral delivery, removing the healthcare professional and the needle from the administration process.

The OraPro platform is ‘plug and play’ – the technology can be applied to create immunity against a range of different pathogens and to the delivery of many therapeutics. Only the DNA insert coding for the infectious disease antigen is changed, and a new vaccine can therefore be created using the same viral vector



Mucosal and
systemic immunity


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The team of doctors and scientists at iosBio believe that the next great leap forward in immunization will be oral delivery

Enabling the fastest and most cost-effective deployment of vaccines the world has ever seen. This is not just a huge leap forward from a humanitarian perspective, oral vaccine technology also represents a significant commercial opportunity.

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