Use of the direct haemolysis-in-gel test for rubella antibodies in the Icelandic prevention programme for congenital rubella.

Untreated earlobe capillary blood samples from 5958 girls were screened for rubella antibodies by placing them directly onto haemolysis-in-gel (HIG) test plates. The method is in our experience quick, reliable and also acceptable to young girls. The method is convenient for testing for natural immunity before vaccination and in most but not all cases satisfactory as a test for seroconversion after vaccination. A comparison was made between naturally infected girls and a group of vaccinated girls. Vaccinated girls had lower values and most of the low or doubtful positives were in this group. Serum samples from 51 low positive girls were tested by the haemagglutination inhibition (HI) test and the serum HIG test and their results compared with their respective direct HIG values.