As part of the SAFESIG-GP project, researchers from SAFEVIC, Victoria’s immunisation safety service, investigated a potential association between mastitis and COVID-19 vaccination requested by the Therapeutic Goods Administration (TGA).

Drawing on multiple sources of evidence, including GP data collected via POLAR, vaccination data, TGA adverse event reports and pharmacovigilance evidence, the research identified an increased incidence of mastitis within 1-28 days of COVID-19 vaccination, particularly following mRNA vaccines.

The findings supported the TGA's identification of an association between mastitis and the mRNA COVID-19 vaccines Comirnaty and Spikevax. As a result, mastitis was added to the Product Information for both vaccines.

The outcome highlights the value of de-identified primary care data in answering important public health questions and strengthening medicines safety monitoring in Australia.

SEMPHN thanks the participating general practices whose contribution of de-identified data made this research possible. Their involvement has helped create Australian evidence that contributes to a change in national medicines safety information.