Anti-diarrhea vaccine receives U.S. approval

WASHINGTON – A vaccine that protects against a virus that is the leading cause of early childhood diarrhea – one that kills hundreds of thousands of infants in developing countries – received U.S. approval Friday.

Many poorer countries have been desperate for the rotavirus vaccine. But it’s unclear how quickly parents and doctors in the United States will embrace it: Seven years ago, the first attempt at a rotavirus vaccine ended in failure after it was linked to deaths and injuries.

The new vaccine, RotaTeq, made by Merck & Co., appears safe and effective, the Food and Drug Administration said. In trials involving tens of thousands of infants, it prevented at least 98 percent of severe cases of gastroenteritis, or intestinal inflammation.

The earlier vaccine, Wyeth’s RotaShield, was pulled from the U.S. market in 1999 after it was linked to a small increase in intussusception, a rare, life-threatening blockage or twisting of the intestine. That could mean an initially cool reception for RotaTeq.

“I’m curious to see how quickly physicians will get back on the bandwagon,” said Scott Henry, an analyst at Oppenheimer & Co.

Trials of RotaTeq, however, indicated it did not increase the risk of intussusception. But Merck officials have said they would conduct a follow-up study to track any long-term effects of their vaccine, which has been in development since 1993.

In the United States, rotavirus sickens about 2.7 million children younger than 5, sends up to 70,000 to the hospital and causes 20 to 70 deaths each year.