THE IMPACT OF HAEMOPHILUS-INFLUENZAE TYPE-B VACCINATION IN SWEDEN

The number of patients with meningitis and bacteremia due to Haemophil us influenzae was studied in Sweden over the period 1987-1994. Conjuga ted H. influenzae type b vaccines were introduced in Sweden in 1992, a nd all children born after December 31, 1992, were offered vaccination free of charge, A rapid decline of H. influenzae meningitis and bacte raemia was observed in the autumn of 1993, when the expected peak inci dence failed to appear, In the prevaccination period 1987-1991, the av erage annual incidence (cases/100,000) was 34.4 in children aged 0-4 S ears. In 1994, the annual incidence fell to 3.5, No significant declin e was observed in older children or adults, There was a 92% reduction in the number of meningitis cases and an 83% reduction in cases of bac teraemia, A similar decline was noted in 2 regions which followed diff erent strategies for the introduction of the vaccination programme.