Measles and rubella seroimmunity in newly arrived adult immigrants in Sweden

Background: International migrants could be considered as a risk group for being susceptible to vaccine preventable diseasessuch as measlesand rubella. However, data on immunity in different migrant groups are scarce. Apart from asylum seekersand refugees, other immigrant groups might also be at risk. We have examined measlesand rubellaspecific IgG antibodies among newly arrived adult immigrants in Skane region in southern Sweden. In contrast to children, adult immigrants are not offered catch-up vaccinations after arrival. Methods: Stored serum samples from 989 asylum seekersand 984 pregnant women from the antenatal screeningprogram, who had recently settled in Sweden, were analyzed for specific measlesand rubellaIgG-antibodies. Sex, age, reason for screening and geographic origin were variables entered into a multivariate regression model. Results: There were considerable differences in seroimmunity to measleswith regard to geographic origin (44–97%). Measlesseroimmunity gaps were most prominent in immigrants from some European regions such as the Baltic countries, the former Yugoslavia and the Newly Independent States and Russia. Seroprotection for rubellavaried less between geographic regions (90–99%). Conclusion: Susceptibility to measlesamong adult immigrants arriving in Sweden varies considerably depending on their geographic origin. Vaccinations against measlesand rubellashould be offered to groups of immigrants who might be incompletely immunized.