A temporary suspension of the initial dose of hepatitis B vaccine appears to have contributed to fewer newborns being vaccinated for hepatitis B in 2000 than in 1998, according to a study published in the May 19 issue of the Journal of the American Medical Association (JAMA)
In 1991, the Advisory Committee on Immunization Practices (ACIP) recommended that all children receive 3 doses of hepatitis B vaccine by 19 months of age, part of a comprehensive strategy to eliminate hepatitis B virus (HBV) transmission in the United States, according to background information in the article. The first dose should be administered within 12 hours of birth to infants whose mothers are hepatitis B surface antigen (HBsAg)-positive or of unknown HBsAg status; vaccination at birth of children of HBsAg-negative mothers is preferred but should not be delayed beyond the age of 2 months.
In July 1999, the recommendation to begin hepatitis B vaccination at birth was temporarily suspended because of concerns about exposure to mercury contained in the vaccine preservative thimerosal. The suspension was lifted in September 1999 when preservative-free hepatitis B vaccine became available.
Elizabeth T. Luman, M.S., of the National Immunization Program, Centers for Disease Control and Prevention, Atlanta, and colleagues evaluated both the immediate and residual impact of the suspension of the birth dose of hepatitis B vaccine on vaccination coverage. The study included an analysis of vaccination status of 41,589 U.S. children born before, during, and after the recommendation to suspend the birth dose.
"In the year before the suspension, [47 percent] of children received a hepatitis B vaccine dose on the first day. First-day coverage decreased to 11 percent among children born during the suspension. For children born in the 6 months after and in months 7 to 12 after the suspension, first-day coverage was 23 percent and 33 percent, respectively (compared with baseline at months 7-12 before the suspension)," the authors write. "This reduction represents 750,000 fewer newborns vaccinated during 2000 compared with 1998." They add that these reductions also represent an excess 182,000 children undervaccinated for hepatitis B at 19 months of age compared with 1998 coverage levels. Coverage with other recommended vaccinations did not decline over this time.
"Effective communication messages are a critical component of rapid changes in vaccination recommendations. Careful assessment of the communication strategies used during and after the suspension of the birth dose of hepatitis B vaccine may provide insights for developing general strategies for disseminating rapid changes in vaccine recommendations, whether due to safety concerns, shortages, or changes in disease incidence," the authors conclude.