Neonatal immunization with hepatitis B (HB) vaccine is highly effective; however, more needs to be learned about the duration of protection and indications for boosters.
Dr Huang and colleagues from Taiwan undertook a study to measure antibody to HB core antigen (anti-HBc), HB surface antigen (HBsAg), and pre- and postbooster titers of HBsAg antibody (anti-HBs).
The researchers included 2 cohorts of 15 year-year-old children and observed them 15 years after primary neonatal immunization with plasma-derived HB vaccines.
Group A consisted of 78 children who were born to HB e antigen-positive HBsAg carrier mothers and had developed protective levels of anti-HBs antibodies (10 mIU/mL) following HB immunization.
Group B consisted of 113 apparently healthy children whose anti-HBs titers after vaccination were unknown.
The researchers were unable to identify anti-HBs (antibody titer <10 mIU/mL) in 29.9% of Group A and 62.4% of Group B.
The research team detected anti-HBc in 33.3 % of Group A and 4.4 % of Group B.
|Single booster augments the serological response to the vaccine in most but not all subjects|
The researchers found that after a single booster dose of HB vaccine, 2.7% in group A and 3.3% in group B remained anti-HBs-negative.
A blunted serological response was noted in approximately 20% in both groups.
The research group noted that there was 1 HBsAg carrier in group A (1.3%) and 4 in group B (3.5%).
The researchers found that 15 years after neonatal immunization with plasma-derived HB vaccine, a large proportion of children exhibited waning immunity.
This poses the risk of breakthrough infection.
The team found that a single booster augmented the serological response to the vaccine in most but not all subjects.
Dr Huang concluded, "Our findings suggest that 1 or more booster immunizations are needed in seronegative subjects by at least 15 years following neonatal immunization with plasma-derived HB vaccine".