Japanese encephalitis (JE) is a mosquito-borne disease transmitted primarily by Culex mosquitoes that places approximately three billion people at risk globally. Despite the availability of vaccines, uptake remains limited in many settings. This systematic review aimed to summarise existing primary research on people's knowledge, attitudes, and behaviours (KABs) regarding JE vaccination to inform vaccine program delivery, policy and practice.
The review searched seven bibliometric databases, examined grey literature and screened reference lists of included studies. Search outputs were independently screened by reviewers. Data extraction and descriptive synthesis methods were applied to the identified primary studies. The review focused on studies reporting KABs towards JE vaccination; further methodological specifics, such as exact databases searched, inclusion and exclusion criteria, or risk-of-bias assessment details, were not reported in the abstract.
Twenty-six studies met the inclusion criteria. Most studies were conducted in JE-endemic countries. The included research examined four main participant groups: travellers from non-endemic settings, caregivers of vaccine recipients in endemic settings, non-traveller adults living in endemic settings, and vaccine providers or advocates drawn from both endemic and non-endemic settings. The abstract does not present full details on study design mix (for example, cross-sectional surveys versus qualitative studies), sample sizes, or geographic distribution beyond endemic versus non-endemic classification.
Findings across the included studies indicated variation in knowledge and awareness by participant group. Adult vaccine recipients—where assessed—generally demonstrated low knowledge and awareness of the JE vaccine. In contrast, caregivers of vaccine recipients showed higher levels of awareness and knowledge. The review highlights a gap in adult recipient knowledge that may contribute to underutilisation of JE vaccination in some populations.
Attitudes toward JE vaccination were reported as generally positive across the studies summarised. Positive attitudes were observed among different population groups, including caregivers and vaccine advocates. The abstract does not provide quantitative measures of attitude or detail on specific attitudinal drivers, but the overall picture is of favourable disposition toward vaccination when awareness or access barriers are addressed.
The review identified multiple influences on vaccination behaviour. Prominent factors shaping KABs included the influence of health workers and community leaders, which affected acceptance and decision-making. Perceived risk of JE also played a role in motivating uptake. Practical barriers identified across studies included cost, time constraints, migration-related issues, and vaccine availability and accessibility. These factors together help explain limited uptake in some settings and point to both informational and structural contributors to suboptimal coverage.
The authors note that there were limited KABs studies on JE vaccination that used rigorous and consistent methodological approaches. The abstract highlights inconsistency and limited methodological rigour across the evidence base but does not specify which quality domains were most affected. This heterogeneity and limited methodological consistency constrain the strength of conclusions and the ability to generalise findings across settings.
The review emphasises the role of health professionals and vaccine advocates as key enablers of JE vaccination. Empowering these groups—through training, resources, and engagement—may increase vaccine uptake. Addressing identified barriers such as cost, time constraints, migration, and accessibility is also essential. The findings support strategies that combine improving knowledge and awareness with removing structural impediments to access. The lack of rigorous, consistent KABs studies further indicates a need for standardised approaches to future research to better inform program design.
This systematic review synthesised data from 26 studies on KABs towards JE vaccination, mostly drawn from JE-endemic countries and spanning travellers, caregivers, non-traveller adults and vaccine providers. Adult recipients often had low awareness of the JE vaccine while caregivers were more knowledgeable. Attitudes were generally positive, and behavioural influences included health workers, community leaders, perceived risk, cost, time, migration, and vaccine availability. The review calls attention to limited methodological rigour and heterogeneity in the KABs literature and recommends focusing on empowering health professionals and advocates alongside addressing practical barriers to improve JE vaccine uptake. Details beyond the abstract, including full methodological parameters and study-level data, were not reported in the source abstract.