Vaccination coverage varied between immigrant groups in Norway, between European countries and between immigrant groups and countries of birth. Immigrants with a long period of residence in Norway had a higher vaccination coverage than those with a short period of residence. There was a clear covariation between vaccination coverage in immigrant groups in Norway and the associated European countries of birth.
Considering the perceived good access to vaccines, attitudes to vaccination and the desire for vaccination are shaped by individual competence and experience, family and the local community, as well as trust in information, the health service and society (11). Attitudes can vary in different countries and in relation to vaccines (18). Vaccine uptake has been reported as being unsatisfactory among young people, ethnic minorities and other socioeconomically vulnerable groups in several European countries (7, p. 18–19). These groups in Norway were uncertain or reluctant to get vaccinated against COVID-19 before vaccination began in this country (2), as well as globally (9, 10, 19). Vaccination coverage also increases among immigrant groups in Norway by age and income, while it has been shown that most of the differences in COVID-19 vaccination coverage between different immigrant groups and people born in Norway cannot be explained by socioeconomic and demographic composition (5). The clear correlation between COVID-19 vaccination coverage in European countries and associated immigrant groups indicates systematic differences in attitudes to vaccination and the desire for vaccination among immigrant groups. This can explain some of the disparity in vaccination coverage among immigrants and people born in Norway beyond that which can be explained by socioeconomic and demographic factors.
The composition of the immigrant groups is younger than in the country of birth, and lower vaccination coverage among immigrants than in the country of birth therefore may be expected, as shown for 15 out of 22 immigrant groups in this study. Immigrants with a long period of residence have a higher vaccination coverage than those with a short period of residence, and there is again reason to assume that age composition plays a part. The covariation with the country of birth was not significantly dissimilar according to the period of residence, which may indicate that systematic differences in attitudes to vaccination and the desire for vaccination influenced by childhood or continued contact with the country of birth endure for some time in immigrant groups.
The COVID-19 vaccination coverage achieved in different countries is influenced by different strategies for vaccination, incentives and restrictions. There has been fairly extensive use of COVID passports (COVID-19 certificates) in Austria (7, p. 18, Belgium (7, p.) 18, Estonia (7, p. 18), France (20), Italy (7, p. 18), Lithuania (7, p. 18), Portugal (21) and Romania (7, p. 18). With the exception of Austria and Romania, the vaccination coverage in these countries in September was higher than in associated immigrant groups in Norway. For example, vaccination coverage among people in Norway who were born in France is closer to the estimate for those who expressed the intent to get vaccinated in France before vaccination began (9) than vaccination coverage in France in September. This may indicate that active use of COVID-19 certificates trumps an initial national tendency to accept COVID-19 vaccines, and may explain some of the differences between immigrant groups and countries of birth. The lower vaccination coverage in immigrant groups than in their countries of birth may also be due to a failure to register vaccines administered in the home country. This can be particularly relevant to the nine countries of birth which had universal access to vaccines before June. Finally, general barriers may explain part of the lower vaccination coverage among immigrants, such as a lack of adapted and simple information about vaccines and lack of knowledge of services, and difficulty getting to the vaccination site (22, 23).
Targeted measures to increase COVID-19 vaccination coverage in different groups require an understanding of specific barriers (22), but there is little knowledge about the reasons for low coverage among countries of birth in Norway (2) and different countries in Europe (7, p. 19). Some factors can be highlighted in accordance with known sources of influence (11, 18), such as certain countries having had historically low trust in the safety and efficacy of vaccines (24) and long-term distrust of national institutions (25). New experiences which can impact on willingness to get a COVID-19 vaccine are variation in vaccine recommendations from country to country, for example for pregnant women (7, p. 12) and in relation to combining different vaccines (7, p. 16). The type of vaccine offered is important (18), and several countries have reported greater scepticism towards certain COVID-19 vaccines (7, p. 19, 26). Misinformation about vaccines (7, p. 19, 21) and negative attitudes among healthcare personnel have been a challenge in some countries (24).
The strength of this study is that there was good access to vaccines in all of the countries included by August 2021 (Table 1), and we can therefore assume that attitudes and willingness provide a better explanation for differences in vaccination coverage than access to vaccines. The study was limited to the correlation between vaccination coverage in the country of birth and immigrant groups from 22 European countries, as access to vaccines, data reporting and vaccination programmes in other countries were considered to be inadequate or too dissimilar to be comparable. It is a strength that the information about vaccination coverage comes from reputable registers. Vaccination coverage figures in the different age groups were available, but were considered to be beyond the scope of this study. Such data may provide more detailed information about covariation, which would be relevant in a follow-up study. The European Centre for Disease Prevention and Control does not have data on vaccination coverage by sex and socioeconomic metrics, which is why it is not possible to explore covariation taking these variables into account. There is a limitation in Norwegian vaccination data in that vaccines administered abroad must be entered individually into the Norwegian Immunisation Registry SYSVAK, with a fee to be paid. We therefore assumed that there was some underreporting of vaccines administered abroad, resulting in somewhat conservative estimates of vaccination coverage in the immigrant groups. County health surveys of different immigrant groups indicate a low level of non-registration of vaccination (unpublished data at present). If people have visited their country of birth and recovered from COVID-19 there, they may consider that to be sufficient immunity, without this being registered in Norwegian data.
We do not consider the limitations in the study to be extensive, and stand by the finding of high covariation between vaccination coverage in the country of birth and immigrant groups. To further explore whether attitudes to vaccines are shaped by their childhoods and contact with their country of birth, thereby influencing vaccination coverage in an immigrant group, it would be interesting to examine whether the differences in immigrant groups in Norway from countries of birth with strong incentives to vaccinate the population may be found in other countries with similar incentives to those in Norway. It would also be interesting to investigate how the level of integration, beyond period of residence, impacts on immigrants' attitudes to vaccination over time.