SAFE [NZ background rates for AESI 2008–2019]

To understand if increased adverse events of special interest (AESI) incidences are attributable to COVID-19 vaccination/s, baseline reference data from before vaccine deployment is required. Baseline data serve as preparation for signal verification and risk assessment should they be required during the programme as well as risk communication. As with other countries, New Zealand did not have the baseline data required to form the basis of robust vaccine safety monitoring. The SAFE project* identified New Zealand background rates over 2008–2019 for adverse events of special interest (AESI) for COVID-19 vaccination.

To establish these rates, New Zealand used the ACCESS protocol developed by VAC4EU. Alignment of New Zealand methodology with global practices enables direct data comparisons and knowledge sharing internationally, with the overall aim of developing robust surveillance systems for vaccine safety. 

The conditions included were based on those developed by the CEPI-funded vaccines via its Safety Platform for Emergency vACcines (SPEAC) project. In response to the pandemic SPEAC established and prioritised a set of AESIs for COVID-19 vaccines. The Brighton Collaboration case definitions provide key criteria to define the level of diagnostic certainty that the presentation is a case. Background rates for other conditions of interest that emerged during the research period were also identified.

The outputs from the SAFE project can be viewed and downloaded from the Data Dashboard.


*This project was funded by the New Zealand Ministry of Health.