Foreign-born individuals and Norwegian-born individuals with foreign-born parents had lower vaccination coverage against COVID-19 than Norwegian-born individuals with Norwegian-born parents, both before and after adjusting for demographic and socioeconomic factors. However, vaccination coverage varies greatly among those with different country backgrounds. Individuals with country backgrounds from Latvia, Bulgaria, Poland, Romania and Lithuania have the lowest vaccination rates, whereas those with country backgrounds from Vietnam, Thailand and Sri Lanka have the highest rates, similar to those of people with a Norwegian background. In the fully adjusted model, the odds ratios for these countries were equal to or only slightly lower than that of Norway.
Surveys conducted shortly before and after COVID-19 vaccines were approved for use in Norway showed large between-group variation in willingness to be vaccinated, with the greatest vaccine hesitancy in those with an Eastern European background (8). The findings from these surveys are consistent with our findings from the registry data. The extent to which differences in vaccination coverage reflect differing attitudes towards vaccines is unclear. A number of factors contribute to vaccination behaviour, and whether or not an individual receives a vaccine depends on far more than them having a positive attitude towards it (16). Practical factors also come into play, such as physical accessibility (distance and opening hours of vaccination centres) and understanding (language and health competence) (17).
An individual's views about a vaccine are shaped both by their close interpersonal relationships (family, friends and colleagues) and by the social and historical contexts in which they live (18). It is therefore to be expected that people who differ greatly in their upbringing and life experiences will also differ greatly in their opinions on and adherence to vaccination programmes. A person's country background may reflect where they grew up and the influences to which they have been exposed over their lifetime, and will thus be a key variable in determining their vaccination status. Being resident in Norway, and having contact with and integrating into Norwegian society, has the potential to modify views that individuals bring with them from their country of birth. People from countries such as Sweden and Denmark that are highly similar in most respects to Norway, and those with country backgrounds often associated with long lengths of residence in Norway, such as Pakistan and Iran, showed strong support for the vaccination programme. By contrast, people with an Eastern European background, who have typically been resident in Norway for shorter periods of time, showed little support for vaccination; out of all those with the shortest lengths of residence, they also had the highest odds of being unvaccinated. However, these differences should be interpreted with caution, as the sensitivity analyses for length of residence did not take into account the fact that the relative proportions of immigrants from different countries may vary over time.
Socioeconomic factors such as income and education also affected vaccination coverage for some country backgrounds. Vaccines are free and readily available in Norway, and it is therefore unlikely that financial constraints per se pose an obstacle to being vaccinated. However, the level and quality of education received by an individual can affect their ability to access and acquire information about the pandemic in general and about vaccines in particular. The relationships between socioeconomic factors, country background and vaccine uptake are complex, and there may well be factors such as integration and length of residence that affect both socioeconomic factors and willingness to be vaccinated. In the long term, measures aimed at increasing levels of education and health competence among immigrant populations should be considered.
Registry data have the obvious advantage of covering the entire adult population of Norway. Nevertheless, our study also has several weaknesses that must be considered when interpreting the results. We do not know how many people received the vaccine abroad without registering it in Norway. This may be particularly relevant for those from countries with good access to vaccines, and where geographical proximity and cheap ticket prices permit frequent travel between Norway and the country of origin. Although some municipalities have introduced systems for registering vaccines received abroad, in many places this will incur a fee, and there are few incentives for the individual to do so. It is difficult to estimate the extent of this issue at present, but since the individuals in our study are permanent residents, we assume that the numbers affected are unlikely to be large enough to change the main findings.
There are also weaknesses related to the income and education registers, including the fact that the data are from 2018. It is also possible that data may have been entered incorrectly, and that the categories used may not always capture individuals' real economic situations or differences in the quality of education received by different groups. The study provides no information about people who are temporarily employed in Norway, who stay for short periods, or who are resident in Norway without a permit. However, it is extremely unlikely that these weaknesses would alter the main findings of the study.