An experimental skin patch developed by U.S. biotechnology company Iomai Corp. protected travelers from diarrhea, the uncomfortable ailment that sickens millions each year.
According to results of a clinical trial published in The Lancet
, travelers who were given the vaccine patch were less prone to suffer from severe diarrhea, or had shorter episodes and milder symptoms than those who had a placebo. The study funded by Iomai Corp. examined 170 travelers to Mexico and Guatemala.
Of the 59 people given the vaccine, 3 suffered moderate or severe diarrhea compared to 23 of 111 who received a placebo. For the three patients who did get sick, in spite of taking the vaccine, the diarrhea only lasted half a day on average.
However, when those who took the placebo became sick, they stayed sick for an average of two days and the illness was severe enough to make them use the toilet twice as often as those on the vaccine, observed the study.
"These results suggest that the Iomai (Corporation) patch has the potential to fundamentally change the way we approach prevention of this disease, an ailment against which we now have very few weapons," said Dr. Herber L. DuPont, professor and director of the Center for Infectious Diseases at The University of Texas School of Public Health and principal investigator of the trial.
The vaccine patch, Iomai's most-advanced product, is in the second of three stages of clinical trials required for regulatory approval. The final study to test the vaccine is due next year. Successful completion of the final study may signal the company's entry to a potential $750 million market, according to Chief Scientific Officer Gregory Glenn.
The vaccine patches used toxins from the disease-causing E. coli bacterium that stimulate the immune system to produce antibodies against the germ. The vaccine patch was devised as the method of delivering the toxins through the skin because earlier tests showed the substances were too dangerous to be injected or delivered either through the mouth or the nose.
"The reason it works so well is that we target the skin, which consists of a very dense number of cells,'' Gregory Glenn said. "We stimulate those very responsive skin cells by adding the toxin that would normally cause the diarrhea.''
According to Iomai's chief scientific officer, the patch may help reduce diarrhea in children and lessen the risk of developing irritable bowel syndrome in adults.
Diarrhea caused by E. coli, is the most common pathogen in travelers' diarrhea that sickens 210 million children each year, killing more than 350,000.
The study was funded by Iomai and conducted with researchers from the John Hopkins Bloomberg School of Public Health and the University of Texas School of Public Health.