Related Experiment Video

Updated: Feb 13, 2026

Detection of Polyfunctional T Cells in Children Vaccinated with Japanese Encephalitis Vaccine via the Flow Cytometry Technique
09:37

Detection of Polyfunctional T Cells in Children Vaccinated with Japanese Encephalitis Vaccine via the Flow Cytometry Technique

Published on: September 23, 2022

2.3K

Early and long term anamnestic response to HBV booster dose among fully vaccinated Egyptian children during infancy

Iman I Salama1, Samia M Sami2, Zeinab N Said3

  • 1Community Medicine Research Department, National Research Centre, Egypt.

Vaccine
|March 14, 2018
PubMed

Insights

Most children vaccinated against Hepatitis B virus (HBV) show a strong early response to a booster dose, even with low or undetectable antibodies. This indicates long-term immune memory, suggesting booster doses may not be necessary for healthy children.

Area of Science:

  • Immunology
  • Vaccinology
  • Public Health

Background:

  • Hepatitis B virus (HBV) vaccination is crucial for preventing infection.
  • Assessing the durability of immune memory after infant vaccination is essential for public health strategies.
  • Many children may lose seroprotective levels of anti-HBs antibodies over time.

Purpose of the Study:

  • To evaluate the early and long-term anamnestic response to a booster dose of HBV vaccine in children who were not seroprotected.
  • To identify risk factors associated with the absence of an anamnestic response to HBV vaccination.
  • To determine the long-term efficacy of the HBV vaccination program in children with waning or undetectable antibody levels.

Main Methods:

  • A national community-based study involving 3600 children aged 9 months to 16 years, fully vaccinated in infancy.
  • Identified 1535 children with non-seroprotective anti-HBs levels (<10 IU/L) and no active infection.
  • Administered a 10 μg booster dose of Euvax HBV vaccine to 1121 children and assessed anti-HBs levels at early (2-4 weeks) and long-term (1 year) intervals.

Main Results:

  • 90.3% of children demonstrated an early anamnestic response after the booster dose.
  • Children with undetectable pre-booster anti-HBs levels (<1 IU/L) had a significantly lower early response rate (85%) compared to those with detectable levels (90%).
  • Absence of early response was predicted by undetectable anti-HBs, rural residence, and older age (15-16 years). After one year, 15% lost their response, predicted by poor early response and undetectable pre-booster anti-HBs.

Conclusions:

  • Immunological memory for HBV vaccine persists even when anti-HBs antibody levels decline or become undetectable.
  • The HBV vaccination program provides effective long-term protection, highlighting the robustness of immune memory.
  • Booster doses may not be necessary for healthy children, as their immune system retains memory of the vaccine.
Abstract

Keywords:
Anamnestic responseHBV vaccineHBs antibodiesHBsAg

More Related Videos

Examining Recall Memory in Infancy and Early Childhood Using the Elicited Imitation Paradigm06:35

Examining Recall Memory in Infancy and Early Childhood Using the Elicited Imitation Paradigm

Published on: April 28, 2016

35.5K
Evaluation of Host-Pathogen Responses and Vaccine Efficacy in Mice08:52

Evaluation of Host-Pathogen Responses and Vaccine Efficacy in Mice

Published on: February 22, 2019

11.3K

Related Concept Videos

Drug Dosing: Infants and Children01:29

Drug Dosing: Infants and Children

Pediatric patient dosages diverge from adults due to disparities in body surface area, total body water, and extracellular fluid per kilogram of body weight. The dosing regimen considers the variations in pharmacokinetics and pharmacology across distinct age groups, encompassing preterm newborns, infants, young children, older children, and adolescents. Calculation of pediatric patient doses is predicated on determining body surface area, which exhibits a superior correlation with the child's...
328
Vaccinations01:51

Vaccinations

Overview
51.9K
Dose-Response Relationship: Overview01:03

Dose-Response Relationship: Overview

Agonists can bind with and activate receptors, resulting in the formation of drug-receptor complexes. Once formed, these complexes catalyze many biochemical processes at the cellular level and subsequently induce a pharmacologic response. The degree of response is directly proportional to the fraction of activated receptors, which in turn, depends on the concentration of the drug at the receptor site as well as the sensitivity of the receptor. An increase in the administered dose contributes to...
5.2K
Dose-Response Relationship: Potency and Efficacy01:22

Dose-Response Relationship: Potency and Efficacy

The potency of a drug is the measure of its ability to produce a biological response and can be compared by looking at the half-maximum effective concentration or EC50 values of different drugs. A lower EC50 value indicates higher potency of the drug. In the dose–response curve of two antihypertensive drugs, candesartan and irbesartan, a significant difference is observed in their EC50 values. A lower EC50 value for candesartan indicates that it is more potent than irbesartan, as it...
6.6K
Dose-Response Relationship: Selectivity and Specificity01:25

Dose-Response Relationship: Selectivity and Specificity

Drugs exert their therapeutic effects by interacting with receptors, enzymes, or ion channels that are present throughout the human body. The strength and duration of the interaction between a drug and its target receptor are characterized by the selectivity and specificity of the drug. Selectivity refers to a drug's strong preference for its intended target over other targets. For instance, isoprenaline, a non-selective β-adrenergic agonist, interacts with both β1- and...
9.9K
Dose Response Curve: Conventional Versus Nonmonotonic01:21

Dose Response Curve: Conventional Versus Nonmonotonic

The correlation between a drug's dosage and its impact on a biological system is a cornerstone of pharmacology and toxicology. Conventional dose–response curves, which include graded and quantal relationships, are key to this understanding. Graded dose–response curves depict the spectrum of a biological reaction to different doses within an individual, indicating that as the drug dosage increases, so does the intensity of the response. On the other hand, quantal dose–response...
1