The project, involving vaccine and immunology experts from around the world, aims to develop cheap, effective oral vaccines that do away with issues associated with needle-delivery of vaccines and will be particularly useful in developing countries.
The research programme involves bacterial spores genetically engineered to express vaccine determinants on the coat, with the research efforts being co-ordinated by Royal Holloway, University of London.
Bacterial spores have thick walls and are resistant to harsh conditions, so are able to survive ingestion and the highly acidic conditions in the human digestive system. Modified spores will therefore be able to deliver the vaccine directly to the gut and induce immunity.
Bacillus subtilis is a harmless gut bacterium that is already available as an oral probiotic to aid digestive health, and has been studied as a promising alternative for development of oral vaccines.
As spores are very resistant they would not require cold storage like other vaccine products, and the oral delivery method would be more consumer friendly and remove safety and compliance issues associated with needle-use, particularly in developing countries.
The initial targets for the research group are malaria and tuberculosis, which combined kill over 2.5 million people worldwide every year according to World Health Organization estimates. It is hoped that once developed, the bacterial spore delivery approach will be able to be applied to a wide range of diseases.
"This consortium brings together creative science from around the world including the UK, Germany, Italy, Austria and Vietnam with the aim of applying modern genetic techniques to develop cheap, effective oral vaccines," said Cobra CEO, David Thatcher.
Cobra is using the collaboration to further enhance its position in oral vaccine research, and already has a proprietary technology for oral vaccine delivery, Ort-Vac.
Ort-Vac is a gene-based oral attenuated bacterial vaccine strain - antigen-encoding genes are cloned onto plasmids and then expressed in attenuated bacteria. The bacteria are then administered orally and delivered to the gut immune system where they stimulate a local and systemic immune response.
Pre-clinical proof-of-principle studies with plague showed a high level of immunity in mice, and the antigen expressed was also very stable compared to expression in a conventional bacteria strain.
The company believes recombinant protein vaccines are becoming increasingly important as a prophylaxis and a therapy, and lists potential indications for the Ort-Vac therapy which include cancer, HIV/AIDS, tuberculosis, avian flu and anthrax.
The company is in the process of seeking development partners for Ort-Vac vaccine applications in humans.
