Question Number: 127
PDR Number: SQ22-000104
Date Submitted: 24/02/2022
Department or Body: Department of Health
Question 27
Yes, background rates of adverse events are only one of the considerations in determining whether a particular adverse event was caused by vaccination.
The Therapeutic Goods Administration (TGA) uses two main approaches to look for new safety information in COVID-19 vaccine adverse event reports with fatal outcomes.
Firstly, the TGA reviews each fatal adverse event report on an individual basis to assess the likelihood that the vaccine contributed to the reported cause of death, as determined by the treating health professional, hospital or coroner. The TGA uses an internationally accepted method for causality assessment of individual adverse events published by the World Health Organization (WHO). Considerations for individual causality assessment do not include the background rate of the event in the population, but do include whether:
– there is strong evidence for a cause other than vaccination in the individual patient
– there is a known causal association between vaccine and the type of event (such as published literature about the association, biological plausibility for the vaccine causing the event, or a specific test result demonstrating the vaccine caused the event in the individual patient)
– the event occurred within a plausible time period after vaccination
– there is a body of published evidence against a causal association between vaccination and the type of event.
Secondly, the TGA also includes these reports in analyses of adverse event report data to look for patterns of reporting that indicate possible safety concerns (or ‘safety signals’), and to investigate safety signals to determine whether there may be a causal link between the vaccine and the type of event.
These analyses may include comparing the occurrence of particular medical conditions within the vaccinated population (based on reporting of adverse events to the TGA) with the background rate. Background rates are derived from the medical literature, international medicine and vaccine regulators and other authoritative sources such as the National Centre for Immunisation Research and Surveillance (NCIRS).
Question 28
Reporting of an adverse event to the TGA does not mean that a doctor considers that it was caused by a vaccine. The TGA encourages reporting of all significant health events after vaccination, even if there is only a small chance that they were caused by the vaccine. Under state and territory regulations in New South Wales, Western Australia, Queensland, Northern Territory and the Australian Capital Territory it is mandatory for health professionals to report adverse events following immunisation.
The TGA reviews each fatal adverse event report to assess the likelihood that the vaccine contributed to the reported cause of death, as determined by the treating health professional, hospital or coroner. This review is designed to determine whether there is evidence that the medical condition that caused death could represent a new safety signal for the vaccine. In some cases, information in the report indicates that the vaccine is very unlikely to have caused the condition that led to death, including where the reporter may state that they do not believe there is a link to vaccination. In other cases, extensive follow-up over weeks or months may be required to gather sufficient information to determine whether the condition that caused death could be linked to vaccination.
Regardless of the outcome of individual case review, reports of fatal adverse events are retained in the TGA database so that they can be included in analyses to identify safety signals that may not be apparent through review of individual cases. This approach is consistent with the internationally accepted approach recommended by the WHO.
