Overview of the Main Anti-SARS-CoV-2 Vaccines: Mechanism of Action, Efficacy and Safety.

This review takes into consideration the principal vaccines developed against the SARS-CoV-2 in this unprecedented period of Covid-19 pandemic. We evaluated the mechanism of action of each vaccine as well as the efficacy, the safety and the storage temperature. In addition, the problem of the dose units, the vaccinal strategy, the activity of alternative compounds such as the monoclonal antibodies and especially the issue of the virus variants were also described in detail. Four vaccines are currently used in Italy: Pfizer-BioNTech mRNA BNT162b2 (Comirnaty) (USA), Moderna mRNA 1273 (USA), Astra-Zeneca ChAdOx1-S (recombinant) viral vector adenovirus belonging to Oxford (UK) and Pomezia (Italy), Janssen (two recombinant viral vector adenoviruses) belonging to Johnson & Johnson (USA). The efficacy of Pfizer and Moderna for preventing disease or severe disease results 95-87.5% and 94.5-100%, respectively. The efficacy of Astra-Zeneca and Janssen is about 70% and 65%, respectively; in the case of Janssen, it depends on the geographical area ranging from 72% to 57%. The problem of the administrated doses (one dose, two doses from the same vaccine or from different vaccines, half dose) is also discussed. The vaccination strategy based on the age group remains the simplest, most transparent and fair criterion. This strategy is also based on accelerating the administration of the vaccines, so that as many subjects as possible can be vaccinated quickly for achieving the "herd immunity". The monoclonal antibodies appeared to be a valid solution for the treatment of Covid-19 disease. Two antibodies (bamlanivimab and etesevimab) have just been approved by the FDA. They could also be used for the infection by virus variants which represent a big problem due to their higher transmissibility and virulence and to their lower response to the vaccines.

Role of Serum E-Selectin as a Biomarker of Infection Severity in Coronavirus Disease 2019.

INTRODUCTION: E-selectin is a recognized marker of endothelial activation; however, its place in Coronavirus Disease 2019 (COVID-19) has not been fully explored. Aims of the study are to compare sE-selectin values among the Intensive Care Unit (ICU)-admitted and non-admitted, survived and non-survived patients and those with or without thrombosis. METHODS: A single-center study of patients with COVID-19 hospitalized at Policlinico Umberto I (Rome) from March to May 2020 was performed. Simple and multiple logistic regression models were developed. RESULTS: One hundred patients were included, with a median age (IQR) of 65 years (58-78). Twenty-nine (29%) were admitted to ICU, twenty-eight (28%) died and nineteen (19%) had a thrombotic event. The median value (IQR) of sE-selectin was 26.1 ng/mL (18.1-35). sE-selectin values did not differ between deceased and survivors (p = 0.06) and among patients with or without a thrombotic event (p = 0.22). Compared with patients who did not receive ICU treatments, patients requiring ICU care had higher levels of sE-selectin (36.6 vs. 24.1 ng/mL; p < 0.001). In the multiple logistic regression model, sE-selectin levels > 33 ng/mL, PaO2/FiO2 < 200 and PaO2/FiO2 200-300 were significantly associated with an increased risk of ICU admission. sE-selectin values significantly correlated with a neutrophil count (R = 0.32 (p = 0.001)) and the number of days from the symptoms onset to hospitalization (R = 0.28 (p = 0.004)). CONCLUSIONS: sE-selectin levels are predictive of ICU admission in COVID-19 patients. Since data on the relation between sE-selectin and COVID-19 are scarce, this study aims to contribute toward the comprehension of the pathogenic aspects of COVID-19 disease, giving a possible clinical marker able to predict its severity.

Persistent Systemic Microbial Translocation and Intestinal Damage During Coronavirus Disease-19.

Microbial translocation (MT) and intestinal damage (ID) are poorly explored in COVID-19. Aims were to assess whether alteration of gut permeability and cell integrity characterize COVID-19 patients, whether it is more pronounced in severe infections and whether it influences the development of subsequent bloodstream infection (BSI). Furthermore, we looked at the potential predictive role of TM and ID markers on Intensive Care Unit (ICU) admission and in-hospital mortality. Over March-July 2020, 45 COVID-19 patients were enrolled. Markers of MT [LPB (Lipopolysacharide Binding Protein) and EndoCab IgM] and ID [I-FABP (Intestinal Fatty Acid Binding Protein)] were evaluated at COVID-19 diagnosis and after 7 days. As a control group, age- and gender-matched healthy donors (HDs) enrolled during the same study period were included. Median age was 66 (56-71) years. Twenty-one (46.6%) were admitted to ICU and mortality was 22% (10/45). Compared to HD, a high degree of MT and ID was observed. ICU patients had higher levels of MT, but not of ID, than non-ICU ones. Likewise, patients with BSI had lower EndoCab IgM than non-BSI. Interestingly, patients with high degree of MT and low ID were likely to be admitted to ICU (AUC 0.822). Patients with COVID-19 exhibited high level of MT, especially subjects admitted to ICU. COVID-19 is associated with gut permeability.