Global background rates study analyzes data from 197 million people for assessment of COVID-19 vaccine safety

The US CDC (Centers for Disease Control and Prevention) funded Global COVID Vaccine Safety Project has generated background incidence rates on a range of conditions designated as AESI (Adverse Events of Special Interest) for COVID-19 vaccine safety monitoring. Conditions studied included myocarditis, pulmonary embolism, and Guillain-Barré syndrome.

Eleven GVDN member sites implemented standardised methods and analysed data from national or regional healthcare databases covering 197 million people from Europe, Asia, North and South America, and Oceania. The study captured data across five pre-pandemic years (2015–2019) and the initial year of the pandemic (2020).

Medical conditions can occur following vaccination but are not necessarily related to the use of the vaccine. Background rates can be used to compare how often the same medical conditions occur before and after a vaccine is introduced. This type of analysis can identify potential vaccine safety signals and support early safety investigations.

GVDN Co-Director Dr. Steven Black states, “With a collaborative global effort not yet seen in the vaccine safety space, the GVDN is pioneering these large-scale studies to assure the safety of vaccines and support public confidence in the safety of vaccines and guide policymaking decisions.”

The findings were recently published in the journal Vaccine. Anastasia Phillips, lead author stated, “This study provides important data that can be used by many countries to investigate reports of medical events following vaccination and to support vaccine safety monitoring.”

GVDN Co-Director Dr. Helen Petousis-Harris says, “The studies that we carry out will be made publicly available to support greater transparency, vaccine safety, more informed risk assessments, and stronger communication efforts.” All data related to this background rates study can be viewed on a dashboard made available for public access at

About the Global Vaccine Data Network (GVDN)

Established in 2019 and with data sourced from millions of individuals across six continents, the GVDN collaborates with renowned research institutions, policy makers, and vaccine related organisations to establish a harmonised and evidence-based approach to vaccine safety and effectiveness. The GVDN is supported by a Global Coordination Centre based at Auckland UniServices Ltd, a not-for-profit, stand-alone company wholly owned by the University of Auckland, that provides comprehensive support to researchers. Aiming to gain a comprehensive understanding of vaccine safety and effectiveness profiles, the GVDN strives to create a safer immunisation landscape that empowers decision making for the global community. For further information visit


This news release summarises the key findings of the GVDN background rates study. To view the full publication in Vaccine, visit All data in the study spans the years 2015¬–2020, with the study occurring between 2022 and 2023. This project is supported by the Centers for Disease Control and Prevention (CDC) of the U.S. Department of Health and Human Services (HHS) as part of a financial assistance award totalling US$10,108,491 with 100% percentage funded by CDC/HHS. The contents are those of the author and do not necessarily represent the official views of, nor an endorsement, by CDC/HHS, or the U.S. Government. For more information, please visit

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