Objective: To determine the duration of protection from
hepatitis B vaccine given in infancy and earlychildhood. Design: Cross sectional serological study of hepatitisB virus
infection in children of various ages 14 years after thestart of a
trial of vaccinationregimens. Setting: Two villages in theGambia. Participants: Children and adolescents given hepatitis B
vaccine in infancy or early childhood: 232 were aged 1-5 years,
225 aged 5-9 years, 220 aged 10-14 years, and 175 aged 15-19years.
Main outcome measures: Vaccine efficacy against infection and againstchronic infection in the different agegroups. Results: Vaccine efficacy against chronic carriageof
hepatitis B virus was 94% (95% confidence interval 89% to 97%),which
did not vary significantly between the age groups. Efficacyagainst
infection was 80% (76% to 84%). This was significantlylower in the
oldest age group (65%, 56 to 73). Of the uninfectedparticipants in
this age group, 36% had no detectable hepatitisB virus surface
antibody. Time since vaccination and a low peakantibody response
were the most powerful risk factors for breakthroughinfection
(P<0.001 in each case). Low peak antibody response wasalso a risk
factor for chronic carriage (odds ratio 95, 19 to466). Conclusions: Children vaccinated in infancy are at increased
risk of hepatitis B virus infection in the late teens. The riskof
chronic carriage after sexual exposure needs further assessmentto
determine if booster vaccines arenecessary.
What is already known on this topic
An expert panel has declared that booster immunisations are not needed for
lifelong immunity to hepatitis B
The evidence for maintenance of immunity in teenagers after vaccination
in infancy is slender
The risk of hepatitis B virus infection is increased by sexual exposure
What this study adds
Teenagers vaccinated in infancy have low concentrations of antibody to
hepatitis B surface antigen
Even though breakthrough infections are common at this age, protection
against chronic infections with hepatitis B virus may be maintained
ALL INFORMATION, DATA, AND
MATERIAL CONTAINED, PRESENTED, OR PROVIDED HERE IS FOR GENERAL INFORMATION
PURPOSES ONLY AND IS NOT TO BE CONSTRUED AS REFLECTING THE KNOWLEDGE OR OPINIONS
OF THE PUBLISHER, AND IS NOT TO BE CONSTRUED OR INTENDED AS PROVIDING MEDICAL OR
LEGAL ADVICE. THE DECISION WHETHER OR NOT TO VACCINATE IS AN IMPORTANT AND
COMPLEX ISSUE AND SHOULD BE MADE BY YOU, AND YOU ALONE, IN CONSULTATION WITH
YOUR HEALTH CARE PROVIDER.
"A foolish faith in authority is the worst enemy of truth."
-- Albert Einstein, letter to a friend, 1901
"I know of no safe depository of the ultimate powers of the society but the people themselves, and if we think them not enlightened enough to exercise control with a wholesome discretion, the remedy is not to take it from them, but to inform their discretion by education."
-- Thomas Jefferson, letter to William C. Jarvis, September 28, 1820
"What's the point of vaccination if it doesn't protect you from the unvaccinated?"
-- Sandy Gottstein
"Who gets to decide what the greater good is and how many will be sacrificed to it?"