Oral Vaccine For Tropical Intestinal Conditions In The Works
June 10, 2013

Researchers Developing New Vaccine Pill For Delhi Belly

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redOrbit Staff & Wire Reports - Your Universe Online

Scientists from the University of Cambridge have developed a new pill that can prevent the condition known as Delhi belly and traveler´s tummy in those visiting India and other tropical nations.

The condition is caused by consuming contaminated food and water, and can lead to cramps, vomiting and diarrhea. However, according to the Press Trust of India (PTI), the new vaccine can help battle the bacteria which causes the ailment.

The new drug targets enterotoxigenic Escherichia coli, which is one of the primary causes of the disease, and it will also offer some protection against another travel-related condition: typhoid. The researchers are reportedly planning to start clinical trials later on this year.

“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,” Professor Nigel Slater, who is heading up the research, told Telegraph Science Correspondent Richard Gray on Sunday.

“It is currently targeting two main bacteria the E. coli that causes Delhi belly and Salmonella that causes typhoid,” Slater added. “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.”

According to Gray, the Cambridge researchers have discovered that they can introduce a small segment of DNA into Salmonella bacteria, making the immune system think it is enterotoxigenic E. coli. The bacteria can be grown in vessels, becoming a fluid mixture of solid and liquid that is then dried using hot gas and turned into a powder.

“This leaves the bacteria in suspended animation until it is dehydrated in the stomach after being swallowed by the patient,” he continued. “To help protect the bacteria from the destructive acid and bile in the digestive system, it is mixed with a powdered resin similar to polystyrene and placed inside a gelatin pill capsule.”

The resin helps absorb the bile, the researchers explained, allowing the bacteria to be rehydrated. Once that happens, it can travel through the lining of the small intestine, inducing an immune response. Slater said that the rehydrated bacteria regain their full function, but they need to be protected up until that point.

“As we are creating immunity at the site where an infection from enterotoxigenic E. coli would normally first occur — in the digestive system — it allows the immune system to be primed against it at the first line of defense,” the professor said. “This should make it more effective than traditional vaccines. We have had some promising results in trials in animals and we are now aiming to start clinical trials in humans later this year.”

They are reportedly working alongside pharmaceutical firm Prokarium to develop the vaccine, which does not need to be refrigerated. That would make it especially useful in developing countries where it is difficult to store traditional vaccines, and would also allow travelers to bring it with them rather than receive injections before their trips, Gray said.

Dehli belly sickens an estimated 10 million people each year, and nearly half of all international travelers are affected by it in some form, The Telegraph reports. Typhoid is responsible for approximately 200,000 deaths annually while as many as half a million individuals, primarily young children, die from enterotoxigenic E. coli, the newspaper added.