Breaking the cold chain for oral recombinant vaccines

New vaccines are made from proteins that have to be injected using a needle. The process of making these proteins is very expensive and different for each vaccine. They cannot be put into tablets because they would be digested in the gut, and they need to be refrigerated and transported around developing countries via a distribution network called the cold chain. This project aims to create a way of making vaccines which is cheaper, requires only one manufacturing process regardless of the type of vaccine, and allows the vaccine to be swallowed as a capsule. These capsules will be designed to be stable without refrigeration for the few critical weeks needed for distribution between cities and remote villages, thus breaking the final link of the cold chain and allowing people to vaccinate themselves. We use a safe strain of Salmonella in the capsule, which produces the required vaccine inside the human body. The technology may revolutionise the way all protein vaccines are delivered and the first proof will be in the form of a vaccine against typhoid and bacterial diarrhoea, which cause hundreds of thousands of deaths annually.