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Vaccines
BayGenetics is developing an inexpensive method to make heat-stable, long-lived vaccines based on B. subtilis spores, which can be administered orally to animals by mixing the genetically engineered spores with drinking water or food.
The method is built around the concept of using bacterial spores as orally or parenterally administered vectors, where the antigens are produced after germination of the spores.
The method stimulates or induces a vertebrate animal or human to produce a humoral or T cell-specific immune response to one or more antigens by genetically engineering bacterial cells which are capable of forming spores. This DNA encodes one or more antigens which are expressed individually or as fusion proteins, and it may also encode other proteins stimulating the immune response as an adjuvant.
The engineered (recombinant) bacterial cells are then induced to form spores, and the spores are orally or parenterally administered to the human or animal to be immunized.
The antigen or antigens encoded by the heterologous DNA are expressed by the ingested bacterial spore and will come into contact with the immune system via the intestinal mucosa.
By "immunize" or "induce an immune response" is meant the production of antibodies or T cell-mediated immune responses by the human or animal so immunized to protect it from future infection by a pathogenic agent.
Advantages
- Inexpensive to produce, transport, store, and administer.
- Using bacterial spores offers a different, conceptually simple, and practical
solution to vaccine antigen delivery.
- Spores are heat resistant and therefore do not require the use of refrigeration for
either transport or storage allowing ambient temperature of vaccine storage in
any climate.
- Provides a means of presenting foreign antigens for vaccine purposes using a
live, heat-stable vector to be administered orally.
- There are clear and undisputed advantages of oral administration in terms of
ease, safety, cost, and acceptability.
- Vaccines made with this system will have a prolonged shelf life, significantly
longer than that of other vaccines.
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