Immune persistence after hepatitis B vaccination in infancy – Fact or fancy?

Abstract

The hepatitis B vaccine has been introduced for more than 3 decades. In Hong Kong, excellent vaccine coverage through an efficient public health care system, together with supplemental programmes and easy availability of the vaccine, meant that most young pregnant women, and university students at entrance, should have been protected. Yet significant correlations in the prevalence of HBV infection with age were found in these groups of subjects, increasing from low to high endemicity rates from late teenage to the early twenties. This can only be attributed to vaccine failure, and there is cumulating evidence that several factors are involved, including the failure to respond to a primary series of hepatitis B vaccination in infancy, the waning of antibody titer with age, and loss of anamnestic response in a significant portion of the vaccinees. The duration of protection conferred by hepatitis B vaccination in infancy should be re-examined and remedial measures undertaken if its long term protection is found to be insufficient. Otherwise, the efforts to control HBV infection, especially in high endemicity regions, with universal vaccination in infancy would be rendered futile.

The effects of booster vaccination of hepatitis B vaccine on children 5–15 years after primary immunization: A 5-year follow-up study

“…11,12 Additionally, immunologic memory will decrease with time after basic immunization. 13 Consequently, the need of revaccination in children has received wide attention.…”

Decreased neonatal hepatitis B virus (HBV) viremia by maternal tenofovir treatment predicts reduced chronic HBV infection in children born to highly viremic mothers

“…On the other hand, postnatal HBV infection is rare but may still occur in this post‐vaccination era. Complete immunoprophylaxis cannot guarantee intact protection and HBV nonresponders (anti‐HBs <10 mIU/mL) or lower titre responders (10‐100 mIU/mL) are susceptible to HBV infection . One infant in the tenofovir group was a low responder to vaccines with inadequate anti‐HBs level (11.1 mIU/mL) at 6 months and was susceptible to HBV breakthrough infection.…”

Long-term persistence of immunity after hepatitis B vaccination: Is this substantiated by the literature?

“…The report by Trevisan 1 and his comments on my earlier review 2 reflected precisely the current confusion about the longevity and protection of the hepatitis B vaccination program. First, Trevisan used data from Italy, where the prevalence of hepatitis B virus (HBV) infection is low relative to places such as Asia, so that the likelihood of exposure to HBV and horizontal transmission after infancy in vaccinated children would be comparatively lower.…”

“…Third, the data provided by Trevisan included only subjects with serological evidence of past HBV infection, but no data on anti-HBs titer or anamnestic response on the rest of the cohort was provided, so that the report still did not constitute proof that the HBV vaccination in infancy confers protection up to adulthood. Finally, the message of my review 2 was not an allegation of lack of efficacy of the hepatitis B vaccine, but rather that we should establish the duration of immunoprotection induced by the HBV vaccine, and to provide remedial actions such as booster doses if longevity of protection cannot be ensured.…”