Evaluation of the Protection Provided by Hepatitis B Vaccination in India

Effectiveness of interventions to improve vaccine efficacy: a systematic review and meta-analysis

BACKGROUND

Vaccination is a crucial public health intervention that has significantly reduced the incidence of infectious diseases. Vaccine-related interventions refer to strategies implemented to enhance vaccination uptake, coverage, and effectiveness, like modes of delivery, types or dosages. Despite extensive research on vaccine efficacy, a comprehensive analysis of the variability in vaccine effectiveness across different interventions, settings, and populations is limited. This study aims to systematically review and meta-analyze the impact of various Vaccine-Related Interventions (VRIs).

METHODS

This review included 139 randomized controlled trials, cohort, and case-control studies evaluating VRIs from January 2015 to December 2023. The risk of bias was assessed using the ROB-2 and ROBINS-E tools. Statistical analyses were conducted to evaluate overall effect sizes, infection rates, and heterogeneity and subgroup analysis.

RESULTS

Of the 139 studies reviewed, 97 were included in the meta-analysis, comprising approximately 1.4 million participants. Populations across various settings were analyzed, with median vaccinated population sizes for the 1st dose (4598, IQR = 15,749), 2nd dose (6214, IQR = 13,817), and 3rd dose (3508, IQR = 5546). The overall total vaccinated population had a median of 4370 and an IQR of 16,475. The interventions showed a significant positive effect on vaccine efficacy, with an estimated effect size of 0.6432 (95% CI 0.4049 to 0.8815). Heterogeneity was negligible, with Tau2 = 0, I2 = 0.00%, and H2 = 1.00. The Galbraith plot suggested minimal variability. The study utilized ROB-2 and ROBINS-E tools to evaluate bias, with Egger's test (t = - 0.9941, p = 0.3227) confirming no significant publication bias. The funnel plot indicated minimal bias in the included studies.

CONCLUSION

The study supports the effectiveness of vaccine-related interventions in enhancing vaccine efficacy. The negligible heterogeneity and consistent effect sizes across diverse populations and settings provide a robust basis for implementing public health strategies aimed at improving vaccination outcomes.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42024543608.

Hepatitis B vaccination in Indian children: Seroprotection and age-related change in antibody titres

BACKGROUND

Childhood immunization against hepatitis B is one of the most effective strategies for reducing the global burden of chronic hepatitis B infection and its sequelae. There are limited data from India on both the anti-Hep B antibody titres in children after vaccination and the age-related decline in the titres. This study was planned to estimate the proportion of children in the age group of 1-10 years who develop protective levels of anti-hepatitis B antibodies after childhood vaccination and to examine the change in antibody titres with age in these children.

METHODS

A hospital-based cross-sectional study was carried out in children admitted to the hospital for various ailments. Basic demographic data, vaccination history and HBsAg status of the mother were recorded. All the enrolled children were evaluated for HBsAg and anti hepatitis B surface antibody (anti-HBS) titres. Institutional ethical clearance was obtained, and informed consent from the parents of the children was taken before drawing samples.

RESULTS

We found that 68.86% Confidence Interval ((CI): 59.8-76.8%) of the children showed protective antibody titres after vaccination, while 31.14% (CI: 23.1-40.2%) of the children had titres less than 10 IU/L. Although 100% of children in the age group from birth to three years had titres more than 10 IU/L, this percentage showed a decline across the age groups, and 60% of children aged 9-10 years had titres less than 10 IU/L.

CONCLUSION

Childhood vaccination against hepatitis B is effective in 68% children, and the antibody levels showed a steady decline with increasing age.