Oral vaccine aims to end dreaded Delhi belly

Each year an estimated 10 million people suffer from upset stomachs in exotic locales. Visitors to Mexico call it Montezuma's revenge, while travelers to India know it as Delhi belly. For years it has been viewed as an almost unavoidable aspect of travel.

Now researchers at the University of Cambridge are talking up the potential of a vaccine to stop traveler's diarrhea. The vaccine targets enterotoxigenic Escherichia coli (ETEC)--one of the most common causes of upset stomachs--and typhoid. A piece of DNA is put into Salmonella bacteria to trick the immune system into thinking it is ETEC. The bacteria is dehydrated during production and placed in a gelatin capsule with powdered resin to stop it from being digested. As the bile is adsorbed by the resin, the bacteria rehydrates and induces an immune response. U.K. biotech Prokarium has licensed the oral-delivery technology from the university.

Enabling oral delivery will make it easier for people to take the vaccine, especially in developing countries. "The vaccine we have produced is a powder so it is very stable and does not need to be kept in cold storage or carries any of the problems associated with needles. … If you were going away for a holiday or on business to India or another country where these diseases are known you would just need to swallow a capsule," University of Cambridge professor and project lead Nigel Slater told the Telegraph.

Clinical trials of the vaccine are expected to start later this year. Researchers have talked up a vaccine for traveler's diarrhea for at least a decade. U.K.-based biotech Microscience presented Phase I data for its vaccine back in 2004. A year later Emergent BioSolutions ($EBS) bought Microscience, only to sell some of the assets to Prokarium in 2012. Prokarium is now combining the acquired capabilities with the University of Cambridge delivery technology to develop a dual oral vaccine against typhoid and ETEC. In March, Prokarium received a grant to further vaccine development.

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