Background: The COVID-19 pandemic has widened inequities, affecting migrant and refugee populations in vulnerable situations, who may face elevated risks of infection, constrained healthcare access and discrimination. Inclusive vaccination campaigns are recommended, but barriers persist. This study aimed to identify barriers and facilitators and estimate vaccination coverage among refugees and migrants in low- and middle-income countries, emphasising inclusive policies for effective rollout.

Methods: A mixed-method study was conducted in two phases in Ecuador, Nepal, Pakistan, the Philippines and Rwanda. Phase 1 (March-May 2022) included policy analysis, in-depth interviews and focus-group discussions with 52 key informants analysed with thematic and grounded theory approaches using hybrid coding. Phase 2 (June-August 2022) included a cross-sectional study among refugees and migrants in regular (MIRS) and irregular situations (MIIS) and used descriptive analysis and a COVID-19 Vaccine Equity Index (CVEI).

Results: A total of 1378 individuals responded to the survey (43.8% MIRS, 31.2% MIIS and 25% refugees). 87% reported receiving at least one dose of the COVID-19 vaccine. The CVEI at the global level (0.824) suggested differences in complete vaccination between migrants and other residents in most of the study countries (refugees reported more access to vaccines than MIRS and MIIS). However, the qualitative phase reported delays and inequities in the early stage of the vaccination process in all countries. Overall, 64.2% of respondents perceived that government' campaigns were successful. Both the qualitative and quantitative phases identified several barriers and facilitators. The main barriers included a lack of trust in authorities, extended waiting times and distance to vaccination centres, discrimination and xenophobia, lack of identity documentation, and adverse reaction concerns. On the other hand, the primary facilitators were the widespread distribution of vaccination centres, sources and provision of information, specific campaigns for refugees and migrants, free vaccination and the motivation to protect others' health.

Conclusions: Despite the high coverage of COVID-19 vaccines among refugees and migrants in the study countries, the process had significant barriers. Simple vaccination registration procedures, targeted campaigns, mobile vaccination teams for hard-to-reach and vulnerable groups, and building trust in the host country authorities are pivotal for future and inclusive vaccine deployments.