After successful clinical trials, researchers are calling for widespread distribution of a vaccine to prevent rotavirus - a severe gastrointestinal illness that kills more than a half a million children around the world each year.
Investigators are urging the use of the rotavirus vaccine in poor and developing countries after two clinical trials that showed it is safe and highly effective in protecting newborns against the deadly virus.
The vaccine, manufactured Merck, already is approved for use in the United States, but researchers wanted to see how well it works in less developed countries.
Dr. Roger Glass is Director of the John E. Fogarty International Center for Advanced Study in the Health Sciences at the National Institutes of Health near Washington.
In an interview from Swaziland, Glass said the vaccine has resulted in a significant decrease in the number of rotavirus cases in the United States.
"The vaccines that we are talking about have been licensed and used in the United States since 2006 and have already made a tremendous impact to reduce hospitalizations and clinic visits for diarrhea in just 3.5 years," said Dr. Glass.
But Dr. Glass noted that rotavirus kills 500,000 children a year in the 72 poorest countries.
Two international trials were carried out to test the vaccine's safety and effectiveness - one involving more than 2,000 healthy infants in Bangladesh and Vietnam. Some of the babies received the oral drug at 6, 10 and 14 weeks of age; another group of infants was given a placebo.
Researchers conducting a follow-up study nearly two years later found the rotavirus vaccine had reduced the number of severe gastrointestinal disease cases by nearly 50 percent.
A second study was conducted in Africa, where rotavirus claims almost a quarter of a million lives each year. Researchers conducting the trial in Ghana, Kenya and Mali, gave three doses of the vaccine to infants without symptoms. Investigators found there were 39 percent fewer cases of severe rotavirus with the vaccine.
Researchers found the vaccine had little or no side effects, according to Dr. Glass, who said widespread use of the rotavirus vaccine would save lives.
"We really hope that we with these results and with these findings that that mortality, those half a million deaths from rotavirus could be reduced by more than 50 percent through the use of this vaccine," he said. "This would further reduce diarrheal deaths in the world by about a quarter. And diarrhea, remember, is the second most common cause of death in children under five."
Three years ago, the World Health Organization recommended routine use of the rotavirus vaccine in countries where it has been found to be safe and effective. Dr. Glass says he hopes the results of these two studies lead to the use of the vaccine in other countries where it is needed most.
The two studies on the effectiveness of the rotavirus vaccine in Asia and Africa are published in the journal The Lancet.