VAC4EU coordinates the preparation and active monitoring of vaccines after market authorization through multiple ongoing projects. Read on to learn more about these and past projects. You can also visit the VAC4EU Zenodo community for reports and other outputs.

Ongoing Projects

Pfizer/BioNTech Comirnaty® Studies

The Pfizer-BioNTech Post-Authorization Safety Studies (PASS) began in 2021 and 2022 with the aim of studying the safety of the Pfizer/BioNTech Comirnaty® vaccine, and to identify incidence rates and potential predictors. Separate studies for focusing on the analysis of myocarditis and pericarditis outcomes for the Pfizer vaccine also began at the request of the PRAC.

Moderna Spikevax® Studies

The Moderna Post-Authorization Safety Study (PASS) began in 2021 and 2022 with the aim of studying the safety of the Moderna Spikevax® vaccine. Separate, focused analyses have also been requested by the PRAC, for pregnancy outcomes as well as myocarditis and pericarditis following the administration of Spikevax, characterizing the history, course, outcomes, and risk factors.  

Registration and Protocols

EUPAS44273. Toft Sørensen H et al. Post-Authorization Active Surveillance Safety Study Using Secondary Data to Monitor Real-World Safety of Spikevax in Europe. 27 September 2021.
EUPAS105009. Ong D et al. Clinical course, outcomes and risk factors of myocarditis and pericarditis following administration of Moderna vaccines targeting SARS-CoV-2.
EUPAS44450. Toft Sørensen H et al. Monitoring safety of Spikevax in pregnancy: an observational study using routinely collected health data in five European countries (COVID-19). 27 September 2021.

Janssen Jcovden® PASS

The Janssen COVID-19 vaccine (Ad26.COV2.S) safety study is a retrospective observational Post-Authorisation Safety Study (PASS) using European Healthcare Data through VAC4EU. So far, we have conducted two feasibility analyses: capturing of COVID-19 vaccine use in the different data sources (13.3 million individuals), characteristics of recipients of COVID-19 vaccines and the occurrence of selected adverse events of special interest (AESIs) after receipt of the Ad26.COV2-S vaccine without consideration of disease-specific risk windows. The data from the data sources proved to be fit for the purpose of conducting the planned final analysis of this study. For the final analysis, we will assess the risk of developing AESIs within disease-specific risk windows following the administration of this vaccine.


EUPAS45362. Ahmadizar F et al. An Observational Post-Authorization Safety Study to Assess the Safety of Ad26.COV2.S Using European Healthcare Data through VAC4EU(COVID-19).

AstraZeneca Vaxzevria® PASS

This project was required by PRAC and aims to identify, characterise, and quantify the risk of safety concerns and AESIs from the AstraZeneca Vaxzevria® vaccine across large and diverse populations. The study includes data from 5 European sites across 4 different countries within the VAC4EU network.

Global Vaccine Safety Project

This three-year project led by the Global Vaccine Data Network (GVDN) began in May of 2022 and aims to assess the safety of COVID-19 vaccines across large and diverse study populations, taking advantage of the 17 countries represented in the GVDN consortium. VAC4EU acts as the coordinating center for the European sites. The goal of the project is to study the association between COVID vaccines and myocarditis/pericarditis, vaccine-induced immune thrombotic thrombocytopenia, Guillain-Barré syndrome, and any potential genetic basis for these reactions. This type of study is an exciting opportunity to innovate with best practices for case validation and participant consent for specimen collection.

Finished Projects

COVID Vaccines Effectiveness (CoVE): Effectiveness of Heterologous and Booster COVID-19 Vaccination in 5 European Countries, Using a Cohort Approach in Children and Adults with a Full Primary Vaccination Regimen

The aim of this project was to study waning immunity after primary COVID-19 vaccine regimens as well as booster vaccinations. The study complemented common test-negative case-control studies, using real world data pulled from other VAC4EU studies, highlighting the advantages of readiness. These data sources represent five countries across Southern, Central, and Eastern Europe, and an estimated 67 million patients.

EMA COVID-19 Vaccine Monitor (CVM): Rapid Safety Assessment of SARS-CoV-2 Vaccines in EU Member States Using Electronic Health Care Datasources

This two-year project was requested by the EMA to extend and build on work from the Early Covid Vaccine Monitor Study (see below) and concluded in April 2023. The purpose of the project was to prepare for and perform a rapid assessment of the association of adverse events of special interest following COVID-19 vaccination. The project collected data from both general and special populations (pregnant and lactating women, children and adolescents, immuno-compromised people, people with a history of allergies, and people with a prior instance of SARS-CoV-2) via self-report within 48 hours of vaccination, using multiple different reporting systems.

EMA Early COVID-19 Vaccine Monitor (ECVM): Cohort Event Monitoring of Safety of COVID-19 Vaccines (Early-) Covid-Vaccine-Monitor

This project was a complement to an EU passive surveillance system for the four COVID-19 vaccines available on the market at the time. The project monitored these vaccines using two complementary methodologies: (1) prospective cohort event monitoring, where vaccinated persons were included and monitored through the internet and incidence rates were calculated, and (2) a retrospective cohort study, where the incidence rates of ACCESS adverse events of special interest were monitored. The study monitored 29 different AESIs both before and after COVID-19 vaccination, including data from nearly 26 million people across eight countries. The focus was primarily on monitoring of incidence rather than signal detection of evaluation.

VACcine Covid-19 monitoring readinESS (ACCESS)

ACCESS was an EMA-funded project with the goal of preparing a European infrastructure to monitor COVID-19 vaccines. The project started May 2020 and ended February 2021. The main outputs of the project were a publicly available list of 27 events of interest along with definitions and codes, a calculation of the background rates of adverse events (See the “Dashboard Background Rates of Adverse Events of Special Interest for COVID-19 Vaccines” tool for more information), guides for localization and adaptation, and a final report with a feasibility assessment. The project also produced template protocols for the following types of real world evidence studies: signal detection based on cohort event monitoring, rapid assessment of new safety signals based on EHR data, safety signal evaluation studies based on EHR data, safety signal evaluation studies with EHR or hospital data, effectiveness studies with EHR or hospital data, and a coverage study with EHR and registry data. Links to these templates can be found on the side bar.

Registration and Protocol

EUPAS37273. Sturkenboom M et al. Background rates of Adverse of Special Interest for monitoring of COVID-19 vaccines. 21 September 2020.

To learn more, or if your organization is interested in requesting a study through VAC4EU, see our Get In Touch page.