ABSTRACT
Introduction: COVID-19 is an acute respiratory tract disease caused by the emerging coronavirus SARS-CoV-2. Although several options for che-moprophylaxis are under development, effective treatment for COVID-19 is not yet available. Objective(s): To investigate the antiviral properties of synthesized silver na-noparticles (AgNPs) against SARS-CoV-2 using in vitro models. Material(s) and Method(s): This work synthesized AgNPs using an electrochemical method and characterized them using physico-chemical techniques (ICP-OES, ultraviolet-visible spectroscopy, and transmission electron microscopy). AgNPs with diameter sizes ranging between 2.6 to 30 nm and an average size of 6.2 nm were obtained by the electrochemical method. The cytotoxic effect and the antiviral activity of prepared AgNPs against SARS-CoV-2 were evaluated in vitro using Vero E6 cells. Cell viability was evaluated by MTT assay in the presence of serial dilutions of AgNPs. The antiviral effect of AgNPs was evaluated before and after the infection of Vero E6 cells by plaque assay. Result(s): Cytotoxic effect was observed at concentrations above 0.07 ppm. AgNPs exhibit a significant reduction of SARS-CoV-2 viral titer after a pre-post treatment strategy with inhibition of 96.5%, 64.13%, and 74.72% at 0.03, 0.017, and 0.008 ppm, respectively. Conclusion(s): Our results suggest that AgNPs could reduce SARS-CoV-2 replication with a low cytotoxic effect. Still, additional in vitro and in vivo studies are required to define its potential therapeutic application in humans. Copyright © 2023 Universidad de Antioquia.
ABSTRACT
This study aimed to identify how rural women and LGBTs, in their diversity, carried out actions to confront COVID-19, having as main foundations popular peasant feminism and gender relations, reinventing their forms of struggle. The methodological procedures are based on militant research, which guides towards a transformative action. Among the main results and reflections, the debates start from the conception of a capitalist, patriarchal, racist, xenophobic and LGBT-phobic society. The actions of struggle and resistance were carried out in solidarity campaigns, denouncements of the denialist and genocidal actions of the Federal Government, the fight for PLs 735/2020 and 823/2021, national and international conferences, defense of the Unified Health System (SUS), tree planting, and reorganizing and reinventing the use of social networks to stay connected.
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.