One-dose hepatitis A vaccination coverage among U.S. infants ages 24 months to 35 months increased from 26.3 percent in 2006 to 47.4 percent in 2007, says a federal government study released Thursday.
The increase followed a 2006 recommendation by the Advisory Committee on Immunization Practices that all children ages 12 months to 23 months be immunized against hepatitis A. Previously, vaccination was recommended only for children who lived in areas where hepatitis A rates were consistently higher than the national average.
The 2006 recommendation also lowered the age for hepatitis vaccine from 24 months or older to 12 to 23 months.
Following the new recommendations, the largest increases in vaccination rates occurred in areas of the United States where hepatitis A vaccination wasn't previously recommended, said the CDC researchers.
The study appears in the current Morbidity and Mortality Weekly Report, which is published by the CDC.
The analysis of one-dose vaccine coverage suggests efforts to implement the new recommendations are well under way, the researchers said. They added that future analysis of two or more vaccine doses will offer a better idea of how well children are being protected from hepatitis A.