Prevention of congenital rubella in Iceland by antibody screening and immunization of seronegative females.

A programme to eradicate congenital rubella from Iceland was started in 1979, based on (1) screening of all females aged 12-45 years for rubella antibodies and (2) vaccination of all seronegative persons with the RA/27/3 rubella vaccine, given free of charge. Thus, individual protection was offered to all who needed it. The collection of serum samples was planned to last for 2 years while, simultaneously, the already established rubella screening and immunization programmes for 12-year-old schoolgirls and pregnant women continued.During assessment in 1983, 95.2% of females in the first 7 age groups (by now aged 14-20 years) participating in the school programme had been tested and 80.4% of them were found to be naturally immune. Of the seronegatives, 93.7% were subsequently vaccinated, thus giving an overall immunity rate of 98.8%. Among the women in the peak of the childbearing period (by now aged 21-35 years), 84.4% had been tested and 92.7% were found to be naturally immune; vaccination of 61.4% of seronegative individuals then gave an overall immunity rate of 97.2% for this age group.If it is assumed that the natural immunity rate of females still untested is like that of the above groups, then the percentage of non-immune persons is at present 2.1% in the younger group and 3.4% in the older.