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Duration of protection after infant hepatitis B vaccination series
Amy B Middleman1, Carol J Baker2, Claudia A Kozinetz2
1Department of Pediatrics, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma; amym@ouhsc.edu.
Insights
Hepatitis B (HB) vaccine protection in adolescents is durable. Most adolescents immunized as infants maintained protective antibody levels and responded well to a booster dose, indicating long-term immunity in low-endemicity areas.
Area of Science:
- Immunology
- Vaccinology
- Public Health
Background:
- Limited data exist on the long-term protection duration of the infant hepatitis B (HB) vaccine series in low HB endemicity settings.
- Understanding this duration is crucial for public health strategies and vaccine schedules.
Purpose of the Study:
- To assess the proportion of adolescents with protective antibody titers after infant HB vaccination.
- To evaluate the response to a challenge vaccine dose in adolescents previously immunized as infants.
Main Methods:
- Enrolled US-born adolescents (16-19 years) who received infant HB vaccine series.
- Assessed antibody to hepatitis B surface antigen (anti-HBs) levels before and after a challenge vaccine dose (10 µg or 20 µg Engerix-B).
- Compared seroprotection rates based on infant vaccination timing, challenge dose, and demographics.
Main Results:
- 24% of participants had protective anti-HBs levels at baseline.
- 92% achieved protective levels after receiving a challenge dose.
- Vaccination group and challenge dosage did not significantly impact post-challenge seroprotection, but factors like group 2, higher test dosage, and nonwhite race were associated with higher post-challenge geometric mean titers.
Conclusions:
- The primary infant hepatitis B vaccine series provides protection extending through adolescence in low endemicity settings.
- Over 90% of participants responded seroprotectively to a challenge vaccine dose, confirming sustained immunity.
- Findings support the continued efficacy of infant HB vaccination schedules.
Background:
Little is known about duration of protection after the infant primary series of hepatitis B (HB) vaccine in settings of low HB endemicity. This study sought to determine the proportion of adolescents immunized as infants who had protective titers of antibody to hepatitis B surface antigen (anti-HBs) before and after a challenge dose of vaccine.
Methods:
US-born 16- through 19-year-olds who received a recombinant HB vaccine 3-dose series initiated within 7 days of birth (group 1) or at ≥4 weeks of age (group 2) and completed by 12 months of age were enrolled. Participants had serologic testing before and 2 weeks after randomization to receive a challenge dose of 10 µg or 20 µg of Engerix-B. Baseline and postchallenge levels of anti-HBs were compared by group, challenge dosage, and demographic and behavioral characteristics.
Results:
At baseline, 24% had protective anti-HBs levels of ≥10 IU/mL; 92% achieved protective levels after challenge dose. Although group 1 had a lower proportion of seroprotection at baseline, group and challenge dosage were not associated with postchallenge proportion of seroprotection. Being in group 2, higher test dosage, higher baseline geometric mean titer, and nonwhite race were associated with significantly higher geometric mean titer after challenge dose.
Conclusions:
More than 90% of study participants immunized against HB as infants exhibited a seroprotective response to a challenge dose of vaccine. Duration of protection from the primary infant HB vaccine series extended through the adolescent years in the setting of low HB endemicity.