What Shapes Childhood Immunisation Uptake in Southeast Asia? A Systematic Review of Barriers, Facilitators, and Interventions — The Association Specialists
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  3. What Shapes Childhood Immunisation Uptake in Southeast Asia? A Systematic Review of Barriers, Facilitators, and Interventions

What Shapes Childhood Immunisation Uptake in Southeast Asia? A Systematic Review of Barriers, Facilitators, and Interventions (24177)

John Carlo Lorenzo 1 2 , Natasha Alexis Marie Jacinto 3 , Tanya Mara Gagalac 4 , Neha Faruqui 1 , Md Irteja Islam 1 , Eduardo Banzon 5 , Holly Seale 6 , Erin Mathieu 1
  1. School of Public Health, The University of Sydney, Sydney, NSW, Australia
  2. Sydney Infectious Diseases Institute, The University of Sydney, Sydney, NSW, Australia
  3. Disease Prevention and Control, Department of Health, Republic of the Philippines, Manila, Metro Manila, Philippines
  4. Philippine Society of Public Health Physicians, Manila, Metro Manils, Philippines
  5. Human and Social Development, Asian Development Bank, Mandaluyong, Metro Manila, Philippines
  6. The University of Sydney, Camperdown, NEW SOUTH WALES, Australia

Background: Childhood immunisation inequalities in Southeast Asia persist despite decades of programme implementation. Evidence on factors influencing immunisation uptake remains methodologically diverse and rarely synthesised. This systematic review consolidates evidence on barriers, facilitators, and interventions influencing priority childhood vaccine uptake in Southeast Asia using the Socio-Ecological Model (SEM).

Methods: We searched MEDLINE, Embase, Ovid Global Health, Scopus, CINAHL, Web of Science, and grey literature in October 2025. Eligible studies examined barriers, facilitators, or interventions affecting uptake of childhood immunisation among children under-five in Southeast Asia. Titles/abstracts and full texts were independently screened, and data extraction and quality appraisal were conducted in duplicate. Findings were synthesised thematically and mapped across SEM levels. The protocol is registered with PROSPERO.

Results: From 14,694 records identified, 99 studies were included: 83 discussing barriers and facilitators, and 16 evaluating interventions. Across 10 Southeast Asian countries, we identified 89 distinct barriers and 70 distinct facilitators to childhood immunisation uptake. Utilising SEM, the greatest number of barriers occurred at the Structural level (n=28), followed by Individual (n=22), Health System (n=21), Interpersonal (n=10), and Community (n=8). Key structural barriers included economic, education and geographic constraints, conflict and crisis-related service disruptions, and population migration. Facilitators were more frequently reported at the Health System level (n=20), followed by Structural (n=18), Individual (n=16), Community (n=9), and Interpersonal (n=7). Key Health System facilitators included immunisation service delivery, health communication, and quality-of-care interactions. Intervention studies primarily targeted strengthening immunisation service delivery, improving access for marginalised populations, and vaccine-promotion and reminder mechanisms.

Conclusion: Overall, barriers to immunisation are most pronounced at upstream structural and systemic levels, while reported facilitators and interventions are concentrated downstream, particularly within health systems and individual behaviours. This misalignment highlights the need for strategies that more directly address structural determinants alongside service delivery improvements to achieve lasting and equitable impact.