Immune responses to hepatitis B immunization 10-18 years after primary vaccination: a population-based cohort study

Area of Science:

• Immunology
• Vaccinology
• Pediatrics

Background:

• Neonatal hepatitis B virus (HBV) immunization is crucial for preventing chronic infection.
• Long-term persistence of vaccine-induced immunity and the need for booster doses in adolescents remain areas of investigation.

Purpose of the Study:

• To evaluate the long-term immune response and seroprotection rates following neonatal HBV vaccination in children aged 10-18 years.
• To assess the anamnestic immune response to a booster dose of HBV vaccine in different age groups.

Main Methods:

• A cohort of 541 healthy individuals, immunized neonatally with three doses of HBV vaccine, were studied 10-18 years post-vaccination.
• Anti-hepatitis B surface antibody (HBsAb) levels were measured, and booster doses were administered to those with suboptimal titres.
• HBsAb concentrations were re-evaluated after booster doses, with data analyzed across three age strata: 10-11, 12-14, and 15-18 years.

Main Results:

• Seroprotection rates decreased with age, from 48% in the 10-11 year olds to 26.5% in the 15-18 year olds (P = 0.008).
• The youngest group exhibited a high anamnestic response rate (96%), while 25% of the oldest individuals failed to respond to a booster dose (P = 0.005).
• Logistic regression identified age and prebooster HBsAb levels as predictors of response to the first booster dose.

Conclusions:

• Neonatal HBV immunization provides durable protection in most individuals, but immune memory wanes significantly by adolescence.
• A notable proportion of older adolescents (up to 25%) may not mount an adequate anamnestic response to a booster, indicating potential vulnerability.
• Further long-term follow-up is essential to ascertain the risk of natural HBV infection and guide recommendations for adolescent booster vaccination schedules.