[Safety surveillance in the National Vaccination Programme; fewer adverse events with the DTP-IPV-Hib vaccine after the transition to an acellular pertussis component in 2005].

OBJECTIVE

To determine the adverse reactions to the combined vaccine against diptheria, acellular pertussis, tetanus, poliomyelitis and Haemophilus Infuenzae type B (DTP-IPV-Hib) before and after the introduction of an acellular pertussis component.

DESIGN

Descriptive.

METHOD: Safety surveillance of the Dutch National Vaccination Programme is performed by the National Institute for Public Health and Environment (RIVM). It is based on an enhanced passive reporting system and complemented by targeted survey-based studies. The data obtained were analysed.

RESULTS

The passive surveillance system showed a large increase in reports in 2004, probably linked to increased media attention on the efficacy and safety of the whole-cell DTP-IPV-Hib vaccine. The Health Council recommended transitioning to the use of a DTP-IPV-Hib vaccine with an acellular pertussis component, which was implemented in January 2005. The number of reports dropped sharply in 2005 to a level below that of 2002-2003. Results of a survey study on adverse events following DTP-IPV-Hib vaccination that began in late 2003 and continued in 2005 confirmed the wide coverage ofthe enhanced passive surveillance system and revealed low rates of underreporting of rare adverse events, such as collapse and convulsions.

CONCLUSION

This study confirms the data from the passive surveillance system, which show that the newly introduced acellular DTP-IPV-Hib vaccine is associated with fewer adverse events than the whole-cell vaccine that was used previously.