228 Understanding vaccination efforts among migrant, mobile and displaced populations

Abstract OP 21: Refugees and Asylum Seekers 4, B308 (FCSH), September 4, 2025, 14:45 - 15:45 Aims Globally, protection against vaccine preventable disease is declining. Even where overall coverage is high, migrant, mobile and displaced populations experience lower vaccine rates. We explored barriers to vaccination, interventions to improve vaccine outcomes and trends in uptake and coverage. Methods We conducted a scoping review looking across the spectrum of migration and displacement, including people who were internally displaced, living in informal settlements, migrants, refugees, asylum seekers, pastoral, nomadic and Gypsy Roma and Traveller communities. We searched PubMed, Embase, and Web of Science, extracting articles with vaccination related outcomes published between January 2014 and January 2025. We excluded reviews, commentaries, seroprevalence studies, cost-effectiveness, efficacy, molecular vaccine development, Covid-19 and mpox vaccine studies. We examined the nature of migration and displacement, demographics, vaccine outcomes and synthesized themes by vaccine, target population and intervention type. Results 388 articles met criteria for full-text screening. Major themes were: unclear policies on access and inclusion, exposure and risk, data and monitoring problems, and common but context-specific barriers faced by these groups. Conflict was a major cause of displacement, but all migrant and mobile populations experienced avoidable barriers to vaccination, including not being identified, offered vaccination, enabled to receive it, inadequate follow up or poor-quality care. Even effective interventions were rarely comprehensive, sustained or mainstreamed. Childhood vaccines were prioritized over adolescent ones, including HPV. Adult vaccination focused on influenza, outbreak and disaster responses, including Hepatitis E and Oral Cholera vaccinations in refugee camps. Conclusions Migrant, mobile and displaced populations remain underserved and under immunized. Effective interventions exist but are not universally available. Data on these and other vulnerable populations are scarce due to neglect by researchers, funders, and publication bias. Future research should address these gaps, including studying how to ensure effective vaccination across the life course and develop sustainable, effective interventions.