Mother's milk contains an acid-based protein that combats a major cause of life-threatening diarrhea in infants, a team led by a Johns Hopkins researcher reported yesterday.
Another team of scientists, also led by a Hopkins researcher, said it has found that a new nose-drop flu vaccine, unlike the standard flu shot, is effective in infants between the ages of 2 months and 6 months.
Both findings were issued yesterday at the combined annual meeting in Baltimore of three groups: the American Pediatric Society, the Society for Pediatric Research and the Ambulatory Pediatric Association.
Dr. Robert Yolken of the Hopkins Children's Center, who led the mother's milk study, said an acid-based protein called mucin blocks the reproduction of a virus that causes diarrhea.
Diarrhea kills about 500 babies in this country each year, and is a leading cause of infant mortality in Third World countries. It can sometimes be a serious threat to elderly patients, Dr. Yolken said, and is the scourge of travelers.
He said the next aim of his team is to figure out how to synthesize mucin and to give it to infants who can't nurse or to older children to prevent infection. Eventually a synthesized protein could be administered even more widely.
The team also hopes to learn how to stimulate nursing mothers to produce more of the protein.
So far, Dr. Yolken and two other researchers -- David Newburg of the Eunice Shriver Medical Center in Waltham, Mass., and Jerry Peterson of the Contra Costa Cancer Center in Walnut Creek, Calif. -- have found that mucin acts to block the spread of rotavirus, a major cause of viral gastroenteritis.
But Dr. Yolken said the protein probably attacks other viruses as well. "We think the virus binds to the mucin instead of the intestinal cells, so it [the mucin] acts as a kind of decoy," he said.
Mother's milk also contains antibodies, and these were previously assumed to be the main disease-fighting mechanism.
But these antibodies are targeted to specific disease-carrying microorganisms. "Mucin may offer a broader range of protection," Dr. Yolken said.
In a separate announcement, Dr. Mark C. Steinhoff of the Hopkins Center for Immunization Research said he and a group of researchers have found a new nose-drop flu vaccine safe and effective.
The researchers administered a weakened influenza A virus nose-drop vaccine to six healthy infants ages 2 months to 5 months while another group of 15 babies received a stronger dose.
Two-thirds of the infants receiving the weak dose, and 90 percent receiving the stronger dose developed influenza antibodies.
Children younger than 6 months run the highest risk of suffering complications from the flu. But infants given flu shots often develop fevers, or shots don't trigger an immune response. Dr. Steinhoff said the infants in his study showed no side effects. If further tests confirm these preliminary results, he said, the nose-drop vaccine could be on the market in a couple of years.