Hepatitis B virus (HBV) infection is a serious public health threat in the
United States with approximately 79,000 new acute cases occurring each year.
Transmission occurs through contact with blood and body fluids. Seventy percent
of acute infections occur during adolescence and young adulthood. About 10% of
newly infected adolescents and adults develop lifelong infections which result
in complications such as chronic hepatitis, fibrosis, cirrhosis, and liver
cancer. HBV infections can be prevented with vaccinations.
In 1994, the Centers for Disease Control and
Prevention (CDC) added vaccination of adolescents to the national hepatitis B
prevention strategy. Since July 1, 1994, North Carolina’s immunization law
requires the hepatitis B vaccination series for all children. In 1995, the North
Carolina Immunization Branch launched a statewide initiative to offer hepatitis
B vaccinations to susceptible sixth-graders in school-site clinics. This
strategy was designed to reach unvaccinated adolescents before the age of
greatest risk of exposure to HBV. Since adolescents attend fewer than one health
care visit each year, the school-site initiative offers an effective plan to
vaccinate this high-risk population. School initiatives are convenient for
parents and increase the likelihood adolescents will complete the recommended
hepatitis B three-dose vaccination series.
North Carolina’s local health departments (LHD)
conduct the Sixth-Grade School-Site Hepatitis B Immunization Initiative in
collaborative relationships with schools with the goal of vaccinating 70 percent
of North Carolina’s sixth-graders against hepatitis B. In the SY 2003-2004
initiative, students who received parental consent for vaccination were eligible
to participate in the initiative. In the 99 participating counties, 42,466 of
109,774 total sixth-grade students received the first dose of vaccine during the
initiative. This number represents 39 percent of the total number of students
and 93 percent of the eligible students who had parental consent to participate
in the initiative. Eighty six percent (36,439) of the 42,466 participating
students completed the three-dose series during the school-site initiative.
Over the past four years, there have been fewer
children participating in the initiative. Decreasing participation rates are
likely due to children being vaccinated by providers outside the school-based
clinics. Insufficient data prevents determination of overall county vaccination
rates. However, the initiative continues to be worthwhile with the
administration of 122,241 doses of hepatitis B vaccine and 17,592 routine Td
booster vaccinations to 42,266 students during the SY 2003-2004 school-site
Recent state and national data reflect the
effectiveness of hepatitis B vaccination. From 1982-1998, national data indicate
a decline in new hepatitis B cases. The greatest decline in disease incidence is
seen among persons 10-19 years of age (73 percent decline), followed by those
20-29 years of age (71 percent decline). In North Carolina, from 1991-2003,
similar decline is seen with 96 percent fewer cases reported in persons 10-19
years of age and 68 percent fewer cases reported in persons 20 years of age and
older. The decline in disease incidence in adolescents is thought to be related
to immunization programs for infants, children, and adolescents.
The North Carolina Sixth-Grade School-Site Hepatitis B Immunization Initiative
is fulfilling its role in the national hepatitis B prevention strategy by
providing a unique opportunity to immunize susceptible adolescents before they
reach the age of greatest risk of contracting disease. The initiative is slated
to continue through SY 2005-2006, when students entering sixth grade should have
been vaccinated, as mandated by state law, prior to school entry.
In recent years, increasing numbers of sixth graders
have received hepatitis B vaccinations outside the school-site clinics.
Inevitably, parents may give consent for previously vaccinated children to
participate in the initiative. In these final two years of the initiative, it is
important to note that collaboration among LHDs, schools and physicians is of
utmost importance to review immunization histories and to avoid administration
of unnecessary doses of vaccine.
Initiative data illustrate the success of
vaccinating more than 521,861 of North Carolina’s adolescents in the past 10
years. While data indicate vaccination programs have been very successful, the
reduction of hepatitis B related liver disease will not be fully realized until
these vaccinated children reach adulthood. The public health benefit of this
immunization program will bring immeasurable dividends for years to come.
To access a paper on this program, "Impact of
Immunization Initiatives on Acute Hepatitis B Incidence in North Carolina
(1991-2005)," click here.