In the last quarter of the year 2000, the meningococcal C conjugated vaccine was incorporated into the routine vaccination schedule in Catalonia (at 2, 4 and 6 months). In addition a vaccination campaign was carried out in children <6 years of age, with a coverage of 96.2%. The effectiveness of the vaccination in this age group during 2001 and the first 28 weeks of 2002 was 100% (94.27-100%). A vaccination campaign has been carried out in 6-19-year olds during 2001 and 2002, with a coverage rate of 23.5% in the year 2001. In this age group a reduction in disease incidence was seen in the 2000-2001 season, but not in the following one.