ABSTRACT
Introduction. The circulation of SARS-CoV-2 virus variants raises concerns about their potential evasion of the immune response and associated clinical consequences. Decay in the magnitude of the immune response over time after completion of the vaccination schedule has been evidenced. The aim of this study was to evaluate the kinetics of neutralizing antibodies after vaccination and the impact of circulating variants. Materials and methods. Prospective longitudinal study' with a cohort of 60 Colombian adults' who received the complete BNT162b2 vaccine schedule' and were followed for 6 months to determine the kinetics of antibodies. Plaque reduction neutralization assays were performed with live virus' using the B.1 lineage (D614G)' and the Gamma' Alpha' Delta' Mu and Omicron variants of the SARS-CoV-2 virus. Results. Neutralizing capacity against all variants was observed in all individuals after 1 month of vaccination;however' a progressive decrease in neutralizing capacity was observed after 3 and 6 months. Compared to the B.1 lineage' the neutralizing response against the Delta' Mu and Omicron variants presented the greatest decrease' evidencing their immune escape capacity' followed by the Gamma and Alpha variants. The decrease in antibody titers was more evident in men older than 40 years. Conclusions. Despite the safety and effectiveness of the vaccines' it is important to improve and monitor them in order to improve the protective response they can offer.
ABSTRACT
Introduction. Infections caused by SARS-CoV-2 may produce a severe inflammatory response, sepsis, respiratory failure, organ dysfunction, and death. From a pathophysiological point of view, it is plausible that glucocorticoids could be a reasonable therapeutic option for Covid-19. However, the evidence supporting the benefit of corticosteroids on mortality and other clinical outcomes is not conclusive. Objective: determinate if there exist evidence supporting corticosteroids therapy in patients with severe Covid-19 and Acute Respiratory Distress Syndrome (ARDS). Material and method: This study was performed in concordance with PRISMA guidelines. According to the PICO strategy, Population were patients with severe Covid-19 and/or ARDS;Intervention, parenteral corticosteroid administration;Comparator, patients with severe Covid-19 and/or ARDS with standard treatment (without corticosteroids);and Outcome, mortality and other clinical outcomes. Search strategy was performed in the data bases PubMed, Medline, Cochrane, Embase, and LILACS, using terms related with the PICO question;from January 1 to august 31 (2020). A total of 287 articles were initially retrieved. Of these, we finally selected only 9 article which fulfilled with PICO and selection criteria. Results: According to our study, parenteral corticosteroids reduce mortality in patients with Severe Covid-19 and/or ARDS [OR 0.83 (IC 95% 0.63-1.08)]. Conclusion: the systematic review shows that parenteral corticosteroids could reduce the mortality of patients with severe Covid-19 and ARDS.