Background In high income countries, the incidence of severe COVID-19 has been disproportionally high among persons with a migration background. We examined determinants of being unvaccinated against COVID-19 in the Netherlands among four large populations of non-Dutch origin with below average vaccination coverage. Methods A nationwide study of determinants of being unvaccinated in the 2021 primary COVID-19 vaccination round in adults and 2022 autumn booster in those ≥60 years was performed within the Netherlands' populations of Dutch-Caribbean, Moroccan, Surinamese and Turkish origin. Using vaccination registry and individual and household level sociodemographic and socioeconomic data, we examined the association between each potential determinant and being unvaccinated using multivariable logistic regression. In addition, we computed population attributable fractions (PAFs). Results Among these populations of non-Dutch origin, the odds of being unvaccinated in both the primary vaccination round and the 2022 booster round were higher among younger persons, migrants with two foreign-born parents, inhabitants of highly or extremely urban areas and persons with low medical risk, lower income and lower education level. The higher odds of non-uptake for migrants with two foreign-born parents (reference: Netherlands-born child with one foreign-born parent) weakened but persisted after adjusting for socioeconomic variables in the populations of Dutch-Caribbean, Moroccan and Surinamese origin (Dutch-Caribbean: aORprimary=3.39 vs. 2.51, aORbooster=2.51 vs. 1.99, Moroccan: aORprimary=2.16 vs. 1.80, Surinamese: aORprimary=1.21 vs. 1.09, aORbooster=2.22 vs. 1.99), and inversed in the population of Turkish origin (aORprimary=1.10 vs. 0.93), while adjusting for additional variables had little effect on the estimate. Similarly to the aORs, the PAFs of young age, being a migrant with two foreign-born parents and having low income, low education level and low medical risk were highest. Conclusion Age, urbanisation level, medical risk, income, education level and migration background were associated with COVID-19 vaccination status among populations of non-Dutch origin. Socioeconomic status only partially mediated the effect of migration background. Although these findings provide some guidance to target vaccination programmes, qualitative and survey-based research is needed to further understand reasons behind lower vaccine uptake and design (community-based) interventions to improve health equity.
