Vaccination coverage and access among children and adult migrants and refugees in the Middle East and North African region: a systematic review and meta-analysis

Background: The Middle East and North African (MENA) region is a major global hotspot for migration with more than 40 million migrants, who may be an under-vaccinated group because of barriers to vaccination within countries of origin, transit, and destination. We systematically synthesised the evidence on coverage, acceptance, drivers of uptake, and policies pertaining to vaccination for children and adult migrants in the region, in order to explore tailored interventions for these groups.

Methods: We searched six databases (including Medline, Embase) for peer-reviewed literature, and other websites (including WHO, IOM, ministries of health) for grey literature on coverage, acceptance, drivers of uptake and policies for any vaccination in migrants in the MENA region from between 2000 and 27 August 2024 in any language. We included studies reporting primary data on coverage, acceptance, and drivers of uptake, and any relevant articles on policies. We defined migrants as individuals who move away from their place of habitual residence, within or across international borders, temporarily or permanently. Studies without disaggregated migrant data were excluded. Primary outcomes were coverage (% individuals receiving ≥1 doses of any vaccine) and acceptance (% individuals accepting any vaccine). We separately synthesised data on children (<18 years) and adults (≥18). Estimates were pooled using a random-effects meta-analysis where possible or narratively synthesised, and drivers of uptake were synthesised using the WHO Behavioural and Social Drivers model. PROSPERO protocol: CRD42023401694.

Findings: We identified 6088 database and 282 grey literature records and included 55 studies and 1,906,975 migrants across 15 countries (including mostly refugees in the Middle East and expatriates in Gulf Cooperation Council countries). COVID-19 vaccination was reportedly provided free of charge to migrants in all countries whereas childhood vaccinations were reportedly provided to migrant children in seven countries. However, for adolescents and adults, there were wide variations across countries, and we found no policies relating to catch-up vaccination. Coverage for childhood vaccination amongst migrants was reportedly low, with only 36.0% of 589 migrant children fully vaccinated according to national schedules (95% CI 35.0%-43.0%, I ² = 67%; data from migrants in Lebanon, Morocco, Sudan). Likewise, data on specific routine vaccines in children was generally low: measles containing vaccines (MCV): MCV dose 1 63.9%-66.9%; MCV dose 2 25.4%-85.6%; oral polio vaccine (OPV): OPV dose 3 65.1%-76.4%; diphtheria, tetanus and pertussis (DTP) containing vaccines: DTP dose 1 81.8%-86.7%; DTP dose 3 59.7%-76.6%). Drop-out rates across all routine vaccines for subsequent vaccine doses ranged from 12.4 to 38.5%, suggesting that migrants face a range of barriers to vaccine uptake beyond the first dose, that need to be better considered when designing interventions. For adults, we found eleven studies on coverage (including 9 on COVID-19) showing that COVID-19 vaccination coverage ranged 33.5-84.8% in migrants and 25.0-59.0% in host populations. Drivers of uptake of childhood vaccination in migrants included limited availability of vaccines and vaccination personnel, communication and administrative barriers, financial difficulties, lack of caregiver knowledge about services, and concerns expressed by caregivers around safety and benefits. For adults, drivers were mainly related to the COVID-19 vaccine and included concerns around safety, quality, side effects, and mistrust in vaccines and the systems that deliver them.

Interpretation: Migrants have unique risk factors for under-immunisation in the MENA region and have low vaccination coverage despite some level of entitlement to services. Data on vaccination coverage, drivers of uptake and policies for migrants in the MENA region is limited to small-scale studies among accessible groups, mostly focusing on COVID-19 compared to routine childhood and adult vaccination. There is an urgent need to strengthen data collection to better understand coverage across different migrant groups, ages, and MENA countries, especially on adult and catch-up vaccinations for routine immunisations, and develop innovative co-designed strategies to address specific drivers of vaccine uptake among this group.

Funding: La Caixa, LCF/PR/SP21/52930003.