Monitoring the safety of drugs and COVID-19 vaccines by the French Pharmacovigilance Centers during the pandemic: A win-win bet with Health Authorities!

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) pandemic virus was a "health crisis" and a significant burden also for the French pharmacovigilance system. It took its toll in 2 phases, the first being in early 2020 when very little was known, and during which the missions of the 31 Regional Pharmacovigilance Centers (RPVCs) from university hospitals were to detect adverse reactions of drugs used in the context of the disease. Whether as a possible aggravating role on COVID-19, or displaying a different safety profile during its course, or to assess safety of curative treatment, this phase preceded that of the arrival of dedicated vaccines. Then the RPVCs' missions were to detect, as early as possible, any new serious adverse effect leading to a potential signal that would modify the benefit/risk ratio of a vaccine and require the implementation of health safety measures. During these two distinct periods, signal detection remained the core business of the RPVCs. Each RPVC had to organize itself to handle an unprecedented surge of declarations and requests for advice, from health care professionals and patients alike. "Leading" RPVCs, who were in charge of monitoring vaccines, had to deal with an extraordinary workload (still going on to this date), to generate in real-time and on a weekly basis, a summary of all the adverse drug reaction (ADR) reports as well as an extended analysis of the different safety signals. The organization put in place at the beginning of the health crisis, adapted to the context of the vaccines, allowed to meet the challenge of real-time pharmacovigilance monitoring, and to identify many safety signals. Efficient "short-circuits exchanges" with the French Regional Pharmacovigilance Centers Network (RPVCN) were paramount to the National Agency for the Safety of Medicines and Health Products (ANSM) to develop an optimal collaborative partnership. The French RPVCN has shown at this occasion both agility and flexibility, swiftly adapting to vaccine- and media-related unrest, and demonstrated its effectiveness in the early detection of safety signals. This crisis also confirmed the superiority of manual/human signal detection over automated ones, as the most effective and powerful tool to date to rapidly detect and validate a new ADR and enable to elaborate rapid risk reduction measures. To maintain the performance of French RPVCN in signal detection and to monitor all drugs as they should, and as expected by our fellow citizens, a new funding model should be considered.