Hepatitis A immunisation in persons not previously exposed to hepatitis A

Cochrane Database of Systematic Reviews, 2012

Publication History Publication Status: New Published Online: 11 JUL 2012 SEARCH ARTICLE TOOLS Abstract Abstract Background In many parts of the world, hepatitis A infection represents a significant cause of morbidity and socio-economic loss.
Whilst hepatitis A vaccines have the potential to prevent disease, the degree of protection afforded against clinical outcomes and within different populations remains uncertain.
Objectives To determine the clinical protective efficacy, sero-protective efficacy, and safety and harms of hepatitis A vaccination in persons not previously exposed to hepatitis A.
Selection criteria Randomised clinical trials comparing HAV vaccine with placebo, no intervention, or appropriate control vaccines in participants of all ages.
Data collection and analysis Data extraction and risk of bias assessment were undertaken by two authors and verified by a third author.
The secondary outcomes were lack of sero-protective anti-HAV immunoglobulin G (IgG), and number and types of adverse events.
Dichotomous outcomes were reported as risk ratio (RR) with 95% confidence interval (CI), using intention-to-treat analysis.
We conducted assessment of risk of bias to evaluate the risk of systematic errors (bias) and trial sequential analyses to estimate the risk of random errors (the play of chance).
Main results We included a total of 11 clinical studies, of which only three were considered to have low risk of bias; two were quasi-randomised studies in which we only addressed harms.
Nine randomised trials with 732,380 participants addressed the primary outcome of clinically confirmed hepatitis A.
Of these, four trials assessed the inactivated hepatitis A vaccine (41,690 participants) and five trials assessed the live attenuated hepatitis A vaccine (690,690 participants).