ATLANTA - The Advisory Committee on Immunization Practices (ACIP) unanimously passed a resolution expanding the age eligibility for hepatitis B vaccine in the Vaccines for Children (VFC) program, the national program that provides free vaccines to children.
Because of a gap in coverage among children ages 7 to 10 years and some adolescents, the committee agreed to expand VFC coverage to include these age groups. The resolution becomes effective March 1, 1998.
The American Academy of Pediatrics (AAP) and the American Academy of Family Practitioners (AAFP) already have existing recommendations for HepB immunization for these age groups, according to AAP liaison representative Neal A. Halsey, MD, Johns Hopkins University, Baltimore.
Halsey stressed the importance of this VFC expansion because "providers are frustrated by not being able to administer the vaccine under the VFC program for some children not eligible and others over the age of 12."
"I think if we've ever had a barrier for improving immunization coverage in this age group, it has been within the hepatitis B program because it has certainly been very confusing and has limited us in terms of trying to provide immunizations to family members and adolescents," said Fernando A. Guerra, MD, ACIP member and director of health for the San Antonio Metro Health District.
Currently, children are eligible for VFC vaccine if they were born on or after Jan. 1, 1991, or if they were born on or after Jan. 1, 1982, and 11 years of age or older. This coverage, however, leaves eligibility gaps for HepB vaccine among children 7 to 10 years and adolescents 16 to 18 years.
Under the current VFC eligibility requirements, adolescents must be classified as high-risk to be eligible for vaccination. However, data shows this is not a common practice among all providers, said Francisco Averhoff, MD, MPH, medical epidemiologist with the Immunizations Services Division of the National Immunization Program (NIP).
These gaps between the VFC eligibility requirements and the ACIP vaccination plan have confused providers about eligibility for VFC vaccine; especially because the eligible and non-eligible ages change, he said.
Currently ineligible 7- to 10-year-olds would eventually pass through the existing 11- to 12-year-old recommendation and have the opportunity to be vaccinated under the current VFC eligibility criteria. However, 16- to 18-year-olds would not have the opportunity for vaccination without a change in VFC eligibility; the exception being those determined to be high risk.
There is currently no national data on HepB vaccination coverage among older children and adolescents. However, using consecutive National Immunization Survey data compiled between 1992 and 1996, it is possible to estimate coverage of younger children. Coverage for children 7-10 years is quite low, Averhoff said, with a percentage of 8%.
Assuming that VFC eligibility expansion results in equal or uniform expansion of vaccine availability and utilization throughout the public and private sector, vaccine coverage would increase every year, he said.
Based on assumptions used to model potential vaccination coverage and the vaccine costs associated with expanding VFC HepB requirements, the third dose is projected at 8% for the first year, 16% for the second, 34% for the third and 50% for the fourth year.
"The VFC eligibility gaps will close in four years due to the aging of the currently eligible cohorts. Therefore, only the four years [1998-2001] are considered in this analysis," said Averhoff.
Additionally, the proportion of vaccine supplied by VFC funds was estimated at 42% of the total; 317 grant funds supply 15% and state and local funds supply 9%. The private sector supplies 34%.
The estimated non-private sector vaccine cost ranged from $8.17 to $9.91 for 7- to 10-year-olds and $9.45 for 16 to 18 year olds - which are the actual current contract costs, he added.
Only 7-year-olds would be affected by the expansion for four years. In contrast, 10- and 18-year-olds would be affected by this expansion for only one year. After that point, the 10-year-olds would be covered under existing VFC eligibility while unvaccinated 18-year-olds would be outside VFC eligibility.
For 10- and 18-year-olds, projected vaccination coverage attributable to this expansion is only 8%; the coverage attained in the first year, 1998. For the cohort of 7-year-olds who would benefit from four years of this expansion, the cumulative coverage is projected to reach 74%, based on the model.
Using the same model, the annual estimated public sector vaccine cost attributable to expanding the VFC eligibility for 1998 ranged from $20 million to $50 million, according to Averhoff.
"Based on the model, the cost increased marginally in the second year and then decreased annually. For the final year, 2001, there would only be vaccine costs for the cohort of current 7-year-olds," he explained.
The effective date for the previous VFC resolution was Jan. 1, but the ACIP voted to change the VFC HepB immunization effective date to March 1, 1998, to give providers enough time to prepare. Barbara DeBuono, MD, New York State Department of Health Commissioner, said more time is needed for implementation of the plan, especially for those running large state health departments and Medicaid programs.
"We have a responsibility as state health departments to make sure our Medicaid providers ... really understand that this is a change in the recommendation," DeBuono said.
These changes will also require the ACIP to modify its own recommendations on hepatitis B immunization, said Harold Margolis, MD, chief of the Hepatitis Branch, Division of Vaccine Research and Development, National Center for Infectious Diseases.
"This VFC resolution goes beyond anything in the ACIP statement," Margolis said.
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