RESUMO
OBJECTIVE: To assess the effectiveness of mass vaccination in Cuba of children under 2 years of age against Haemophilus influenzae type b (Hib), the most common causative pathogen of bacterial meningitis. METHODS: The availability of effective Hib conjugate vaccines led to a nationwide vaccination program in 1999 targeting all children under 2 years of age, with a 97% coverage rate achieved. To assess the program's impact, data from 1998 and 1999 from the National Bacterial Meningitis Reporting System were used. RESULTS: Vaccination efficacy was estimated at 99%. The overall incidence of Hib meningitis declined 46.1%, from 1.3 to 0.6 cases per 100,000 population. The greatest overall reduction, of 56.1%, occurred among children under 5 years of age. Among children under 1 year of age, the reduction was 70.5%, and among the rest of the age groups of children under 5, incidence decreased between 25.9% and 49.6%. In the group targeted for vaccination, incidence decreased 61.1%. Among children in the target group who contracted Hib meningitis, only 8 cases (24.2%) had been vaccinated, most with a single dose applied 1 month before becoming ill. CONCLUSIONS: Hib vaccination of all children under 2 years of age in Cuba greatly reduced the incidence of Hib meningitis, as measured by the National Bacterial Meningitis Reporting System.