Covid-Vaccine-Monitor: a Cohort Event Monitoring Safety Study of COVID-19 Vaccines in Twelve European Countries: An International Journal of Medical Toxicology and Drug Experience

ABSTRACT

Introduction: Since the WHO declared the COVID-19 global pandemic in March 2020, vaccines to prevent severe SARS-CoV-2 infection have been developed at unprecedented speed. Several vaccines have been conditionally authorized by regulators in December 2020 already. The large-scale vaccination campaigns have undeniably raised the importance of post-authorization evaluations not only through spontaneous reporting but also by cohort event monitoring to obtain more in-depth vaccine safety information, rapidly after launch. Objective: To monitor COVID-19 vaccine safety and estimate the frequency of solicited and non-solicited, non-serious and serious reactions. Methods: We designed a prospective cohort event monitoring (CEM) study as part of the Covid-Vaccine-Monitor (CVM) project. The CEM collects baseline data, adverse reactions (ADRs) of authorized COVID-19 vaccines in the general and special populations (pregnant and lactating women, children, and adolescents, immunocompromised, allergic, and prior COVID-19 infection people) in twelve countries (Germany, Croatia, Netherlands, Belgium, Italy, France, Spain, Portugal, Slovakia, Romania, Switzerland, and UK). The current results comprise data from February 2021-February 2022. Depending on the dose and cohort, two data collection platforms are used the Lareb-managed Intensive Monitoring (LIM) and the UMC Utrecht Research Online (RO). Germany and Croatia used their national tools. Participants meet local age criteria, have a first vaccination cycle or a booster dose within 48 hours, and are followed up for 6 months. Data are pooled, stratified by special cohorts, and analyzed. Results: We included more than 30,000 general population participants data from Belgium, Croatia, France, Italy, Netherlands, and UK, and more than 520,000 from Germany with the first vaccinations. Across different vaccines, 0.2-0.3% reported at least one serious ADR after receiving the first doses. More than 7,400 special cohorts vaccinees participated. 0.2% and 0.4% reported at least one serious ADR and adverse event of special interest (AESI), respectively, after the first vaccinations. The most-reported ADRs among vaccines were injection site pain, locally, and fatigue, headache, malaise, and myalgia, systemically. Serious ADRs and AESIs were uncommon. More than 11,100 vaccinees from general and special cohorts receiving a booster dose were also included. Among different cohorts, children/adolescents reported the lowest number of ADRs, while lactating women reported the highest. Conclusion: We collected and analyzed COVID-19 vaccines safety evidence in more than 550,000 general and special population persons after the first cycle and booster doses, combining data from twelve countries. Data confirm common ADR rates that are already listed in the summary of product characteristics, and that serious reactions are uncommon. Additional follow-up is ongoing.