Sept. 5 (Bloomberg) -- Pediatricians have seen 20 percent fewer American toddlers for a common ear infection since Wyeth started selling its Prevnar vaccine for fighting bacteria in 2000, a study found.

The decline represents 246 fewer visits a year for each 1,000 children younger than two, said researchers from Vanderbilt University and the U.S. Centers for Disease Control and Prevention. Prevnar reduces the risk of otitis media, an infection of the inner ear.

The earaches are so common among American children that pediatricians probably haven't detected a decline in cases in their own practices, the researchers said. There are more than 800 visits to the doctor for otitis media for every 1,000 children under 2 years of age, even with the help of Prevnar, the researchers said.

``It's really encouraging that they found that drop in the study, but I still see a lot of ear infections,'' said Ari Brown, a pediatrician in Austin, Texas, who is the author of ``Baby 411: Clear Answers and Smart Advice for Your Baby's First Year,'' in a Sept. 1 telephone interview.

The journal Pediatrics published the study on Prevnar in its September issue. The research will help doctors persuade parents to get vaccines for their children, said Rebecca Jaffe, a family- practice doctor in Wilmington, Delaware. She wasn't involved in the study.

The vaccination is one of about a dozen recommended by the CDC for children and adolescents. Parents sometimes question the value of all of them, Jaffe said in a Sept. 1 interview.

``This study will be another piece of information to give them,'' she said.

Checking Up

Marie Griffin of Nashville, Tennessee-based Vanderbilt, one of the study's authors, said she and colleagues set out to test whether Prevnar was living up to expectations. Madison, New Jersey-based Wyeth wasn't connected to the study, which mined CDC records to track doctor visits for otitis media.

``When the CDC makes recommendations about new vaccines, it's important to see if the vaccine delivers what was promised,'' Griffin said in a Sept. 1 telephone interview.

Griffin and colleagues divided the records of doctor visits from 1994 through 2003. Comparing visits in 2002 and 2003 with those from 1994 to 1999, they found a ``striking'' reduction, the researchers said. The research confirms an earlier study based on records from the Medicaid government health plans for the poor.

``It's nice that they were able to confirm the earlier findings,'' said Kimberly Center, associate director for clinical affairs for Wyeth's vaccine division, in a Sept. 1 interview.

Prevnar sales rose 60 percent to $518 million in the second quarter. Wyeth, which struggled to meet demand for the product in its first years on the U.S. market, said Prevnar is now the world's best-selling vaccine.

To contact the reporter on this story: Kerry Young in Washington kdooley@bloomberg.net

Last Updated: September 5, 2006 00:21 EDT