evidence: 99 million people included in largest global vaccine safety study 19 February 2024 The Global Vaccine Data Network, hosted at the University of Auckland, utilises vast data sets to detect potential vaccine safety signals The Global Vaccine Data Network (GVDN) assessed 13 neurological, blood, and heart related medical conditions to see if there was a greater risk of them occurring after receiving a Covid-19 vaccine in the latest of eight studies in the Global COVID Vaccine Safety (GCoVS) Project.