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 diseases such as measles and rubella. However, data on immunity in different migrant groups are scarce. Apart from asylum seekers and refugees, other immigrant groups might also be at risk. We have examined measles and rubella specific IgG antibodies among newly arrived adult immigrants in Skåne 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 seekers and 984 pregnant women from the antenatal screening program, who had recently settled in Sweden, were analyzed for specific measles and rubella IgG-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 measles with regard to geographic origin (44-97%). Measles seroimmunity 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 rubella varied less between geographic regions (90-99%).

Conclusion: Susceptibility to measles among adult immigrants arriving in Sweden varies considerably depending on their geographic origin. Vaccinations against measles and rubella should be offered to groups of immigrants who might be incompletely immunized.