Most adolescents have not been vaccinated against hepatitis A virus, leaving them vulnerable to serious disease as they move into adulthood, a cross-sectional study showed.
In 2009, only 42% of U.S. teens ages 13 to 17 had received at least one dose of the vaccine and only 29.5% had received two doses, according to Christina Dorell, MD, MPH, of the CDC's National Center for Immunization and Respiratory Diseases in Atlanta, and colleagues.
Rates were highest in states that had been covered by recommendations for routine hepatitis A vaccination the longest, the researchers reported in the February issue of Pediatrics.
Guidance from the Advisory Committee on Immunization Practices (ACIP) regarding hepatitis A vaccination has evolved over time, starting with a 1996 recommendation for routine two-dose vaccination for children 2 and older who were living in communities with the highest rates of infection.
In 1999, ACIP modified the guidance to recommend routine vaccination for children living in 11 states that had infection rates at least twice the national average and consideration of vaccination in six states that had rates higher than -- but not double -- the average.
Finally, in 2006, ACIP recommended routine vaccination for all U.S. children starting at age 1, bringing the remaining 33 states and the District of Columbia into the fold.
Gradual implementation of the recommendations has been associated with a dramatic drop in rates of hepatitis A infection in the U.S. The virus likely will persist, however, because of introductions through contaminated food, international travel, and international adoption, placing unvaccinated individuals at risk.
To assess vaccine coverage in U.S. adolescents, Dorell and colleagues turned to the 2009 National Immunization Survey-Teen, which collected information through landline telephone surveys of parents and guardians and mailed surveys of vaccination providers.
Most of the 20,066 teens, ages 13 to 17, included in the current analysis had not received any doses of vaccine by 2009.
One-dose coverage was 74.3% among the states covered by a routine vaccination recommendation since 1999; 54% among those covered by a recommendation for consideration of the vaccine since 1999; and 27.8% for the remaining states not covered by a recommendation until 2006.
The most consistent predictor of having been vaccinated was receipt of a recommendation from a healthcare professional. That was associated with a 30% to 160% relative increase and 21% to 34% absolute increase in coverage rates among the three groups of states.
"Recommendations from healthcare providers increase parental acceptance of vaccination, and parents change their minds about delaying and refusing vaccines because of information or assurances from healthcare providers," according to Dorrell and colleagues.
Only one-quarter of the teens in the study received such a recommendation, however.
"Provider concerns about vaccine reimbursement and insurance coverage and some physicians' perception that hepatitis A is not a significant health problem have been identified as barriers to recommending [the vaccine]," the authors wrote.
"As a result, it may be useful to continue educating vaccination providers about the severity of hepatitis A infection among adolescents and adults and the safety and high efficacy of [the vaccine], which can be given to anyone needing or wishing protection."
Aside from provider input, other factors that were tied to vaccination rates were presence of a state requirement, racial and ethnic background, type of living area (urban, suburban, or rural), household income, and geographic region.
The researchers acknowledged some limitations of the study, including the possibility that it may not be representative of households without landline telephones. Also, they relied on parental report to determine whether a healthcare provider gave a recommendation about the vaccine. There was the possibility of nonresponse bias and the potential for incomplete information from the provider regarding vaccination.
source: Medical News
No comments:
Post a Comment