RUBELLA IMMUNITY AND MORBIDITY - IMPACT OF DIFFERENT VACCINATION PROGRAMS IN FINLAND 1979-1992

As the previous vaccination of 11- to 13-year-old girls proved ineffec tive, nationwide vaccination of preschool children with 2 doses of com bined vaccine against measles, mumps, and rubella was started in Finla nd in 1982. To study the impact of vaccination, age-stratified rubella immunity and the occurrence of serologically verified rubella cases w ere determined using the computerized data of our diagnostic virus lab oratory. The analysis covered the period 1979-1992, included all ages, and was based on the test results from 94,000 sera. By 1992, the sero positivity rate was 92-100% in 2- to 15-year-old children, remained hi gh in females of all ages, but showed a gap in 16- to 19-year-old male s. The number of verified rubella cases decreased to about 1/100, but outbreaks still occurred until 1991, when most cases were among adoles cent males. The better protection of women was due to the vaccination of prepubertal girls since 1975. No congenital rubella infections were diagnosed after 1986. The 2-dose immunization of preschool children, complemented by selective vaccination of certain other groups, has res ulted in excellent immunity in children and young adults, and practica lly eliminated rubella from the country.