Oral vaccines made from silkworms
As winter approaches, many people are likely getting seasonal influenza vaccines. While seasonal influenza vaccines are typically administered via subcutaneous injection, vaccine administration using syringes is currently the major method.
On the other hand, in recent years, the usefulness of oral vaccines has been attracting attention from various perspectives.
- Individuals who have an aversion to injections can also be vaccinated. Additionally, this method can avoid the risk of medical accidents associated with syringes.
- Since the recipient takes the vaccine themselves, it reduces the burden on doctors and enables efficient large-scale vaccination during a pandemic.
- As a solid formulation, it does not require a cold supply chain and can be transported and stored even in regions with poor infrastructure.
However, developing oral vaccines is challenging, and currently, the only orally approved human vaccine in Japan is the attenuated live rotavirus vaccine. Oral vaccine development is difficult because the protein, which is the main ingredient of the vaccine, breaks down into amino acids when taken orally.
At KAICO, we have focused on VLPs (Virus Like Particles: empty particles composed only of viral shell proteins without genetic information) produced using the silkworm-baculovirus expression system. Certain VLPs, while being proteins, are resistant to digestive breakdown and can reach the intestines, inducing immunity. We are working daily to develop vaccines using VLPs manufactured in silkworms.
A transmission electron microscope image of norovirus VLP derived from silkworm
Moreover, as a stepping stone for human oral vaccine development, we have successfully demonstrated the effectiveness of an immunoenhancing feed for pigs using proteins produced in silkworms.
KAICO has proven its extremely significant advantages in this modality and is steadily moving forward towards the development of human oral vaccines.
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