More than half of the estimated infections of the disease; which can cause flu-like symptoms and jaundice; occurred in children, the study from the U.S. Centers for Disease Control and Prevention said.
A highly effective hepatitis-A vaccine became available in the United States for children age 2 or older in 1995, according to the report in this week's Journal of the American Medical Association.
A year later medical experts recommended targeting vaccinations toward children living in communities with higher incidence of the disease, such as Native American settlements.
Adults with high risk of the disease, such as men who have sex with men, users of illegal drugs and travelers to countries where the disease is endemic, were also targeted for vaccinations.
In 1999, recommendations for routine vaccination were expanded to include children living in 17 states that had consistently elevated hepatitis A rates.
Cases fell 76 percent to 2.6 per 100,000 people in 2003 compared to the early and mid-1990s, researchers found.
Declines were greatest in children ages 2 to 18, at 87 percent, the report said.
