Surveillance of adverse events following immunisation: Australia, 2000-2002.

The Adverse Drug Reactions Advisory Committee (ADRAC) database collates notifications of adverse events following immunisation (AEFI) from across Australia. The data were analysed for vaccines received between 1 January 2000 and 30 September 2002. Dose-based AEFI reporting rates were calculated using denominator data from the Australian Childhood Immunisation Register and annual national influenza vaccination coverage surveys. The majority of the 2,409 AEFI records analysed described non-serious events, principally injection site reactions; 10.5 per cent (n = 253) described AEFIs with outcomes defined as 'serious'. Ten deaths were recorded but only one, following yellow fever vaccine, was causally related to immunisation. The average annual population-based reporting rate was 4.5 per 100,000 population. Vaccine dose-based AEFI reporting rates were 2.2 per 100,000 doses of influenza vaccine for adults aged 40 years and over and 14.6 per 100,000 doses of all scheduled vaccines for children aged less than 7 years. The most frequently reported type of adverse event was injection site reaction following receipt of an acellular pertussis-containing vaccine, particularly among children in the age groups scheduled to receive their fourth or fifth doses of the vaccine (overall reporting rate 67 per 100,000 doses). The data highlight the safety of vaccines in Australia, and illustrate both the utility of available immunisation coverage data to estimate dose-based AEFI reporting rates and the value of the ADRAC database as a surveillance tool for monitoring AEFIs nationally.