Journal of Infectious Diseases
1 November 2009  Volume 200, Number 9
http://www.journals.uchicago.edu/toc/jid/current

Major Articles and Brief Reports
Viruses
Antibody Levels and Protection after Hepatitis B Vaccine: Results of a 22-Year Follow–Up Study and Response to a Booster Dose

Brian J. McMahon, Catherine M. Dentinger, Dana Bruden, Carolyn Zanis, Helen Peters, Debbie Hurlburt, Lisa Bulkow, Anthony E. Fiore, Beth P. Bell, and Thomas W. Hennessy

Background.
The duration of protection in children and adults (including health care workers) resulting from the hepatitis B vaccine primary series is unknown.

Methods.
To determine the protection afforded by hepatitis B vaccine, Alaska Native persons who had received plasma‐derived hepatitis B vaccine when they were >6 months of age were tested for antibody to hepatitis B surface antigen (anti-HBs) 22 years later. Those with levels <10 mIU/mL received 1 dose of recombinant hepatitis B vaccine and were evaluated on the basis of anti‐HBs measurements at 10–14 days, 30–60 days, and 1 year.

Results.
Of 493 participants, 60% (298) had an anti‐HBs level 10 mIU/mL. A booster dose was administered to 164 persons, and 77% responded with an anti‐HBs level 10 mIU/mL at 10–14 days, reaching 81% by 60 days. Response to a booster dose was positively correlated with younger age, peak anti‐HBs response after primary vaccination, and the presence of detectable anti‐HBs before boosting. Considering persons with an anti‐HBs level 10 mIU/mL at 22 years and those who responded to the booster dose, protection was demonstrated in 87% of the participants. No new acute or chronic hepatitis B virus infections were identified.

Conclusions.
The protection afforded by primary immunization with plasma‐derived hepatitis B vaccine during childhood and adulthood lasts at least 22 years. Booster doses are not needed.