Researchers from the UK-based medical technology company Cambridge Biostability -- in accordance with the University of Cambridge and funded by a $2.6 million grant from the Department of Trade and Industry -- are working to develop a slow-release type of vaccine that would eliminate the need for booster shots. The prototype, which uses controlled-release nanoparticles that release the vaccine over the span of a few weeks, could be available by 2011.

Bruce Roser, lead scientist at Cambridge Biostability, noted that the new type of vaccine would be kept at room temperature by suspending its nanoparticles in an inert liquid. The particles would be based on calcium phosphate -- the compound from which human bone is made -- and would be easily broken down by the body.

"A serious problem with [current vaccines] is the need for boosters to achieve effective immunization," said Roser. "This costs an enormous amount of money and is not always possible because people do not always come back for their next injections."

This new version of vaccine would have immense potential for use in developing countries, where funding and storage facilities are both limited. "If you have to [vaccinate] only once, the savings are enormous and the extra money could be used to purchase additional vaccines and save a great many lives," said Roser. "Initial studies are promising."