Table 1 Determinants of under-vaccination among migrant populations

Information inequities

• Limited access to health information leading to inadequate knowledge about vaccinations and vaccine-preventable diseases [11, 12]

• Language barriers and/or low literacy [10,11,12,13]

• Vaccine misinformation [3, 10, 14]

• Low health literacy [10, 15]

• Information not accessible or not provided in an acceptable format [11]

• Inadequacy of public health vaccination campaigns targeting migrant groups [16]

• Confusion related to vaccine eligibility [17]

Personal beliefs

• Low risk perception of vaccine-preventable disease [13]

• Vaccine-specific hesitancy (e.g. fears of adverse effects, vaccine safety concerns) [1, 11, 18]

• Ethnic, cultural, or religious values [1, 11, 12, 18]

Previous systems experiences

• Experiences of racism, discrimination, or social exclusion within health systems [1, 10, 11, 15, 19]

• Distrust of the health/medical system and/or government systems [10, 12, 15]

• Fear of accessing the healthcare system based on legal status (e.g., undocumented migrants) [14, 17]

Structural inadequacies

• Inadequate vaccine delivery coordination by public health authorities [11, 14]

• Gaps in national policies on migrant/refugee health services and vaccinations [1, 11, 19]

• Lack of vaccine coverage in the country of origin [14]

• Barriers or inequities to accessing healthcare in general that translate to vaccine access [1, 19]

Accessibility of vaccine services

• Lack of awareness and/or physical access to immunization services [11]

• Difficulties navigating the healthcare system [1, 19]

• Low digital literacy and lack of access to technology for booking and accessing information [11]

• Financial barriers accessing vaccination; including indirect costs such as taking time off work [1, 9, 11, 19]

Intersecting risk factors for under-vaccination

• Level of education [13]

• Income [1, 19]

• Family size, birth order of child [11]

• Age [7]

• Country/continent of origin [7, 20]

• Geographic location (e.g., rural/urban, neighbourhood) [7, 21]

• Faith and/or culture [1, 11, 12, 18]

• Legal status [14]