Rubella in Seattle-King County Washington.

Assessment of the results of rubella hemagglutination-inhibition tests from women of child-bearing age in Seattle-King County suggests no community susceptibility problem except among women age 19 in 1976. Within this cohort 23 per cent were susceptible, probably because these women were too young to experience a full exposure to natural rubella prior to introduction of rubella vaccine and too old to be immunized against rubella in the elementary schools in 1970. Follow-up of women under age 25 who were seronegative for rubella antibody indicated that one-third subsequently received rubella vaccine.