Introduction

PSR Consulting Ltd was running part of the European Research Programme for Improved Vaccine Safety (EUSAFEVAC) during the years 2001-2003. The overall objective was to provide a scientific basis for improved vaccine safety surveillance by initiating systematic review of some adverse events; exploring problems in current surveillance systems; establishing standard case definitions for important adverse events; developing standard procedures of data collection for vaccination registers; and testing the developed tools in a comparative study of passive reporting systems and a model for active surveillance.