1 figure, 1 table omitted
Hepatitis A vaccine was first licensed in the United States in 1995.
In 1996, the Advisory Committee on Immunization Practices (ACIP) recommended
vaccination of children aged ≥24 months in populations with the highest
incidence of hepatitis A (e.g., American Indian/Alaska Native [AI/AN], Asian/Pacific
Islander, and selected Hispanic and religious communities).1 In
1999, these guidelines were expanded to recommend routine vaccination for
children residing in 11 states* where average annual hepatitis A incidence
during 1987-1997 was at least 20 per 100,000 population (twice the national
average) and to consider routine vaccination for children in six states†
where average annual incidence was 10-20 per 100,000 population.2 This
report is the first national analysis of hepatitis A vaccination coverage
among children. The results indicate that, in 2003, vaccination coverage levels
with at least 1 dose of hepatitis A vaccine for children aged 24-35 months
varied from 6.4% to 72.7% in areas where routine vaccination is recommended.
In addition, hepatitis A vaccination coverage rates for children aged 24-35
months are lower than overall rates for other vaccines recommended for children.3 Sustaining and improving vaccination coverage among
young children is needed to ensure continued declines in hepatitis A incidence
in the United States.
The National Immunization Survey (NIS) provides annual estimates of
vaccination coverage as of the time of household interview among children
aged 19-35 months for the 50 states and 28 selected urban areas. In 2003,
NIS began to collect data regarding hepatitis A vaccination coverage. Hepatitis
A vaccine is a 2-dose regimen (administered at least 6 months apart) licensed
for use in children aged ≥24 months. Hepatitis A vaccination coverage data
were limited to children aged 24-35 months and calculated by considering children
who had received at least 1 vaccine dose. To collect vaccination data for
all age-eligible children, NIS uses a quarterly, random-digit–dialing
sample of telephone numbers for each of the 78 survey areas and determines
vaccination status from health-care provider records.4,5 During
2003, information on vaccination history was collected from telephone interviews
for 19,979 children; provider verified vaccination records were available
for 13,731 (68.7%).
Among children aged 24-35 months residing in the 11 states where routine
hepatitis A vaccination is recommended, 50.9% (95% confidence interval [CI] = 47.6%-54.2%;
range among states: 6.4%-72.7%) received at least 1 dose of hepatitis A vaccine.
Among children aged 24-35 months residing in the six states where routine
hepatitis A vaccination should be considered, 25.0% (CI = 21.8%-28.2%;
range: 0.6%-32.3%) had received at least 1 dose of hepatitis A vaccine. Among
children aged 24-35 months residing in the 33 states without a specific recommendation,
1.4% (CI = 1.0%-1.8%; range: 0.0%-4.3%) had received at least 1
dose of hepatitis A vaccine. Two states (Alaska and Arizona) and four urban
areas had coverage estimates >60%. Hispanic and AI/AN children had higher
coverage rates than non-Hispanic white or black children in areas where routine
vaccination is recommended or should be considered.
A Fiore, MD, B Bell, MD, Div of Viral Hepatitis, National Center for
Infectious Diseases; L Barker, PhD, N Darling, MPH, National Immunization
Program; J Amon, PhD, EIS Officer, CDC.
The national hepatitis A vaccination coverage estimates described in
this report indicate that, in 2003, current hepatitis A childhood vaccination
recommendations were being implemented in many states. However, coverage varied
among areas and populations, likely because of targeted programs within these
states. For example, higher coverage in El Paso County, Texas (71%), compared
with the overall Texas coverage rate (32%), likely is attributable to vaccination
requirements in Texas border counties for all children attending child care
Vaccination coverage also varied by race/ethnicity. Higher coverage
among Hispanic and AI/AN children than among children of other racial/ethnic
populations might be related to greater disease recognition in these populations
and local and national vaccination recommendations that have identified these
populations as having higher hepatitis A rates.6,7
The findings in this report are subject to at least three limitations.
First, NIS is a telephone survey; although statistical weights adjust for
nonresponse and households without telephones, some bias might remain. Second,
although NIS relies on provider-verified vaccination histories, incomplete
records or reporting could result in underestimates of coverage. Finally,
although national estimates are reliable, estimates for states and urban areas
and for racial/ethnic populations should be interpreted with caution.8
The 1999 ACIP hepatitis A prevention recommendations encouraged state
and local immunization programs to analyze their surveillance data and implement
vaccination strategies that address the epidemiology of hepatitis A in their
areas. The variation by state in coverage among children aged 24-35 months
likely reflects the varying vaccination strategies adopted by state and local
public health officials in response to the ACIP recommendations. Higher coverage
among Hispanic and AI/AN children is one indication that vaccination efforts
targeting children at higher risk for illness have been successful.
These data do not provide information on why hepatitis A vaccination
coverage for children aged 24-35 months remains below that for other childhood
vaccinations in most areas where it is recommended. Low coverage rates for
young children might be the result of (1) a focus by health-care providers
and immunization programs on vaccinating older children, (2) the few areas
with hepatitis A vaccine mandates,9 or (3)
the lack of a licensed hepatitis A vaccine that can be administered to children
aged <24 months. Sustaining and improving vaccination coverage among young
children is needed to ensure continued declines in hepatitis A incidence in
the United States.
*Alaska, Arizona, California, Idaho, Nevada, New Mexico, Oklahoma, Oregon,
South Dakota, Utah, and Washington.
†Arkansas, Colorado, Missouri, Montana, Texas, and Wyoming.
Hepatitis A Vaccination Coverage Among Children Aged 24-35 Months—United States, 2003. JAMA. 2005;293(12):1443-1444. doi:10.1001/jama.293.12.1443