Background: Support for the COVID-19 vaccination programme has been high in Norway throughout the pandemic, but previous studies have observed variation based on country of birth. If the unvaccinated are young and healthy, the risk and consequences for the individual and for the health service will be less than if the unvaccinated have underlying risk of severe COVID-19. The purpose of the study was to examine the degree to which vaccination coverage varied by country of birth in persons with and without underlying risk.
Material and method: We used the Norwegian emergency preparedness register Beredt C19 to link vaccination coverage to demographic and health variables. Using Poisson regression, we estimated the relative likelihood of being vaccinated for foreign-born individuals compared to Norwegian-born individuals, for those with and without underlying risk of severe COVID-19, adjusted for sex, age, level of education, household income and county.
Results: The study population was 4 304 249, which included 768 312 people who were born outside Norway. The vaccination coverage varied in total from 47 to 94 % between countries of birth. The variation between countries of birth was less in the group with underlying risk, ranging from 63 to 96 %. The difference between persons with and without an underlying risk was most pronounced among those born in Poland (RR 0.71 and 0.55) and Lithuania (RR 0.69 and 0.61). In absolute numbers, this corresponded to a difference in relative risk of 0.16 and 0.08, respectively.
Interpretation: Higher vaccination coverage against COVID-19 among persons with an underlying risk means that the variation between countries of birth may have had less serious implications in terms of severe clinical course and healthcare needs than previously assumed.