Annual report: surveillance of adverse events following immunisation in Australia, 2004

This report summarises Australian passive surveillance data on adverse events following immunisation (AEFI) for 2004 and describes reporting trends over the five years, 2000 to 2004. AEFIs are notified to the Adverse Drug Reactions Advisory Committee by state and territory health departments, hospitals, doctors and other health providers, vaccine manufactures, and the public. There were 975 AEFI records for vaccines received in 2004. This is an annual AEFI reporting rate of 4.8 per 100,000 population, the lowest since 2000, and a 33 per cent decrease compared with 2003 (1,460 records; 7.1 AEFI records per 100,000 population). Dose-based AEFI reporting rates in 2004 were 1.8 per 100,000 doses of influenza vaccine for adults aged >= 18 years and 11.8 per 100,000 doses of scheduled vaccines for children aged <7 years. The majority of records described non-serious events while nine per cent (n=88) described AEFIs defined as 'serious'. There were no reports of death related to immunisation. The most frequently reported individual AEFI was injection site reaction in children following a fifth dose of an acellular pertussis-containing vaccine (67 reports per 100,000 doses). The marked reduction in the AEFI reporting rate in 2004 coincided with the removal of the fourth dose of acellular pertussis vaccine, due at 18 months of age, from the vaccination schedule in September 2003 and fewer people receiving meningococcal C vaccine through the national catch-up vaccination program for those aged 1-19 years in 2004, compared with 2003. The consistently low reporting rate of serious AEFIs demonstrates the high level of safety of vaccines in Australia.