From infancy and beyond… ensuring a lifetime of hepatitis B virus (HBV) vaccine-induced immunity

Abstract

Despite the long-term efficacy and immune persistence observed following HBV vaccination of infants, the need for a booster dose following infant immunization continues to be deliberated. Evidence from HBV booster dose response studies and long-term immunization program reviews are the basis for the recommendation that a vaccine booster is not necessary. However, further studies continue to emerge and highlight the need for standardization among observational studies in order to appropriately compare outcomes. There is an assumption that neonatal and infant (within 12 months of age) vaccine immune responses are equivalent; however, evidence exists for distinct vaccine responses within the first year of life. HBV vaccine programs have evolved over time, particularly regarding the type and dosage of vaccine used. Several universal neonatal immunization programs initially incorporated a 2.5 μg dosage (Recombivax-HB, Merck). This dosage has been shown in multiple long-term studies and meta-analyses to be associated with a lower primary response, decreased antibody persistence over time, and a reduced booster response 10 to 20 years following immunization. Ongoing surveillance of this and other HBV neonatally-vaccinated populations, particularly in low endemic regions, is necessary to understand the impact on long-term protection in order to ensure lifelong protection against hepatitis B infection.

Immunization against Hepatitis B Surface Antigen (HBsAg) in a Cohort of Nursing Students Two Decades after Vaccination: Surprising Feedback

“…The different immunological response that was observed among young healthcare professionals who were vaccinated during infancy and during adolescence could be, at least in part, attributable not only to the maturity of the immune response system at the time of the first vaccination cycle completion, but also to the lower dosage contained in the neonatal anti-HBV vaccines compared to some vaccines administered during adolescence [23].…”

Asymptomatic hepatitis B carriers who were vaccinated at birth

“…The most important issue concerning HBV vaccination is its long‐term efficacy in preventing HBV infection. Whether booster doses of vaccine are necessary to maintain long‐term immunity remain under debate because there are no eligible randomized clinical trials to determine whether a booster dose is required or not . We reported previously that the prevalence of HBsAg among adults born from 1987 to 1993 increases with age, although they had received a first dose within 24 hours of birth .…”

Hepatitis B vaccine development and implementation

“…62 Although it is still a concern whether the long-term protection in vaccinees who received reduced quantity of HBsAg (2.5 μg dosage, Recombivax-HB, Merck) or in individuals with high-risk of HBV exposure, such as healthcare workers, the immunity to HBV is appropriately maintained. 63,64 A booster dose in vaccinees who previously received primary hepatitis B vaccination during infancy appears not required, because the vaccinees with anti-HBs <10 mIU/mL or undetectable have brisk anamnestic immune response to HBsAg and authentic breakthrough infection of wild-type HBV with severe outcomes (acute hepatitis B or chronic carrier) in successfully vaccinated individuals is extremely rare. 65 Nevertheless, ongoing surveillance of vaccinees is required to clarify whether primary hepatitis B vaccination can confer longer or even lifelong protection.…”