Optimizing Safety Surveillance for COVID-19 Vaccines at the National Pharmacovigilance Centre Lareb: One Year of COVID-19 Vaccine Experience

Introduction: Due to the COVID-19 vaccination campaign, national pharmacovigilance (PV) centres had to deal with high volumes of Individual Case Safety Reports (ICSRs) that needed to be processed and assessed in a short time span. This necessitated the development of a dedicated system to enable near real-time vaccine safety monitoring at the Dutch PV Centre Lareb.

Objectives: To describe infrastructure, processes and Adverse Events Following Immunisation (AEFIs) reported for vaccine safety monitoring of COVID-19 vaccines during a large-scale vaccination campaign in the Netherlands.

Methods: A COVID-19 tailored vaccine web-based reporting form collected information on the vaccine administered, AEFIs and other (medical) information. A fully automated process for ICSRs enabled the handling of the majority of common and known reported AEFIs. All other ICSRs were triaged daily and processed separately. There were daily signal detection meetings and weekly reports for batch analysis.

Results: In 2021, Lareb received 184,411 ICSRs, a reporting rate of 0.67% for vaccines given in the Netherlands. 887,954 AEFIs were reported, mostly well-known, nonserious AEFIs; 2.4% were serious and 0.3% were fatal. 33.1% of all ICSRs were processed fully automatically. Based on the daily triage, 4.2% were flagged as 'high priority'; 62.7% as 'low-priority'. Twenty-seven signals and news stories about the COVID-19 vaccines were disseminated.

Conclusions: Due to automatic processing of well-known AEFIs, daily triage and signal detection meetings, 99.9% of the ICSRs were processed within the compliance timeframe to Eudravigilance, and signal detection was performed during a large-scale vaccination campaign. These experiences may serve as a blueprint for future mass vaccination programs.