Mumps prophylaxis in the light of a new test for antibody.

A radial haemolysis test was used to investigate immunity to mumps. Antibody was found in 92 (42%) out of 220 children aged up to 5 years, 124 (78%) out of 159 children aged 6--10 years, 192 (86%) out of 222 children aged 11 years, 138 (92%) out of 150 children aged 15 years, and 280 (95%) out of 296 women attending an antenatal clinic. A group of 307 cadets aged 16--18 years were also tested and interviewed: 133 (95%) out of 140 who said that they had had mumps and 108 (87%) out of 124 who said that they had not had mumps were found to have antibody. The results suggest that tests for immunity to mumps by radial haemolysis would permit more rational use of mumps-specific immunoglobulin and attenuated mumps vaccine.