Safety Monitoring of COVID-19 Vaccines:Perspective from the European Medicines Agency

Prior to deployment of coronavirus disease 2019 (COVID-19) vaccines in the European Union in 2021, a high vaccine uptake leading to an unprecedented volume of safety data from spontaneous reports and real-world evidence, was anticipated. The European Medicines Agency (EMA) implemented specific activities to ensure enhanced monitoring of emerging vaccine safety information, including intensive monitoring of reports of adverse events of special interest and the use of observed-to-expected analyses. The EMA also commissioned several independent observational studies using a large network of electronic healthcare databases and primary data collection via mobile and web-based applications. This preparedness was key for two high-profile safety signals: thrombosis with thrombocytopenia syndrome (TTS), a new clinical entity associated with adenovirus-vectored vaccines, and myocarditis/pericarditis with messenger RNA vaccines. With no existing case definition nor background rates, the signal of TTS posed particular challenges. Nevertheless, it was rapidly identified, evaluated, contextualized and the risk minimized thanks to close surveillance and an efficient use of available evidence, clinical expertise and flexible regulatory tools. The two signals illustrated the complementarity between spontaneous and real-world data, the former enabling rapid risk identification and communication, the latter enabling further characterization. The COVID-19 pandemic has tremendously enhanced the development of tools and methods to harness the unprecedented volume of safety data generated for the vaccines. Areas for further improvement include the need for better and harmonized data collection across Member States (e.g., stratified vaccine exposure) to support signal evaluation in all population groups, risk contextualization, and safety communication.</p

Lessons Learned on Observed-to-Expected Analysis Using Spontaneous Reports During Mass Vaccination

During the COVID-19 vaccination campaign, observed-to-expected analysis was used by the European Medicines Agency to contextualise data from spontaneous reports to generate real-time evidence on emerging safety concerns that may impact the benefit-risk profile of COVID-19 vaccines. Observed-to-expected analysis compares the number of cases spontaneously reported for an event of interest after vaccination (‘observed’) to the ‘expected’ number of cases anticipated to occur in the same number of individuals had they not been vaccinated. Observed-to-expected analysis is a robust methodology that relies on several assumptions that have been described in regulatory guidelines and scientific literature. The use of observed-to-expected analysis to support the safety monitoring of COVID-19 vaccines has provided valuable insights and lessons on its design and interpretability, which could prove to be beneficial in future analyses. When undertaking an observed-to-expected analysis within the context of safety monitoring, several aspects need attention. In particular, we emphasise the importance of stratified and harmonised data collection both for vaccine exposure and spontaneous reporting data, the need for alignment between coding dictionaries and the crucial role of accurate background incidence rates for adverse events of special interest. While these considerations and recommendations were determined in the context of the COVID-19 mass vaccination setting, they are generalisable in principle.</p

Hemithioindigo-based molecular motors controlling helicity in liquid crystals by visible light

Molecular motors are promising tools for the amplification of the motion from nanoscale to macroscopic scale. In this account, hemithioindigo-based molecular motors are presented since they can rotate under irradiation with visible light, making them interesting for biological applications in which the use of the UV light must be reduced. Since these molecules have a tetrasubstituted double bond, their synthesis require several reactions and, in this work, a new synthetic approach with fewer steps and an opportunity of a post-functionalization is presented. The strategy involves a convergent synthesis in which the lower and upper halves are synthesized separately, and joined through a coupling reaction. Chiral purification and full characterization of the thus synthesized functionalized motors were carried out. The integration of an enantiomerically pure hemithioindigo-based molecular motor in nematic liquid crystals can promote the formation of a cholesteric mesophase, which is characterized by a helical conformation leading to a chiral system. Each isomer can lead to a cholesteric helix with different pitch and handedness. The power of a chiral dopant to induce the formation of a cholesteric mesophase was determined by the helical twisting power (HTP)

Light sedation with dexmedetomidine: a practical approach for the intensivist in different ICU patients

Light sedation, corresponding to a Richmond Agitation-Sedation Scale between 0 and -1 is a priority of modern critical care practice. Dexmedetomidine, a highly selective, central, α2-adrenoceptor agonist, is increasingly administered in the intensive care units (ICUs) as an effective drug to induce light sedation, analgesia and a quasi-physiological sleep in critically ill patients. Although in general dexmedetomidine is well tolerated, side effects as bradycardia, hypertension, and hypotension may occur. Although a general dosing range is suggested, different ICU patients may require different and highly precise titration that may significantly vary due to neurological status, cardio-respiratory function, base-line blood pressure, heart rate, liver efficiency, age and co-administration of other sedatives. This review analyzes the use of dexmedetomidine in different settings including pediatric, adult, medical and surgical patients starting with some considerations on delirium prevention and sleep quality in critically ill patients and how dexmedetomidine may contribute to these crucial aspects. Dexmedetomidine use in specific sub-populations with unique characteristics will be detailed, with a special attention to a safe use