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Here, we performed single-cell RNA sequencing of S1 and receptor binding domain protein-specific B cells from convalescent COVID-19 patients with different clinical manifestations. This study aimed to evaluate the role and developmental pathway of atypical memory B cells (MBCs) in response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. The results revealed a proinflammatory signature across B cell subsets associated with disease severity, as evidenced by the upregulation of genes such as GADD45B, MAP3K8, and NFKBIA in critical and severe individuals. Furthermore, the analysis of atypical MBCs suggested a developmental pathway similar to that of conventional MBCs through germinal centers, as indicated by the expression of several genes involved in germinal center processes, including CXCR4, CXCR5, BCL2, and MYC. Additionally, the upregulation of genes characteristic of the immune response in COVID-19, such as ZFP36 and DUSP1, suggested that the differentiation and activation of atypical MBCs may be influenced by exposure to SARS-CoV-2 and that these genes may contribute to the immune response for COVID-19 recovery. Our study contributes to a better understanding of atypical MBCs in COVID-19 and the role of other B cell subsets across different clinical manifestations., (© 2024 The Author(s). Journal of Medical Virology published by Wiley Periodicals LLC.)

Introduction: This study evaluated the immune response to a multiepitope recombinant chimeric protein (CHIVAX) containing B- and T-cell epitopes of the SARS-CoV-2 spike's receptor binding domain (RBD) in a translational porcine model for pre-clinical studies., Methods: We generated a multiepitope recombinant protein engineered to include six coding conserved epitopes from the RBD domain of the SARS-CoV-2 S protein. Pigs were divided into groups and immunized with different doses of the protein, with serum samples collected over time to determine antibody responses by indirect ELISA and antibody titration. Peptide recognition was also analyzed by Western blotting. A surrogate neutralization assay with recombinant ACE2 and RBDs was performed. Intranasal doses of the immunogen were also prepared and tested on Vietnamese minipigs., Results: When the immunogen was administered subcutaneously, it induced specific IgG antibodies in pigs, and higher doses correlated with higher antibody levels. Antibodies from immunized pigs recognized individual peptides in the multiepitope vaccine and inhibited RBD-ACE2 binding for five variants of concern (VOC). Comparative antigen delivery methods showed that both, subcutaneous and combined subcutaneous/intranasal approaches, induced specific IgG and IgA antibodies, with the subcutaneous approach having superior neutralizing activity. CHIVAX elicited systemic immunity, evidenced by specific IgG antibodies in the serum, and local mucosal immunity, indicated by IgA antibodies in saliva, nasal, and bronchoalveolar lavage secretions. Importantly, these antibodies demonstrated neutralizing activity against SARS-CoV-2 in vitro ., Discussion: The elicited antibodies recognized individual epitopes on the chimeric protein and demonstrated the capacity to block RBD-ACE2 binding of the ancestral SARS-CoV-2 strain and four VOCs. The findings provide proof of concept for using multiepitope recombinant antigens and a combined immunization protocol to induce a neutralizing immune response against SARS-CoV-2 in the pig translational model for preclinical studies., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Mosqueda, Hernández-Silva, Vega-López, Vega-Rojas, Beltrán, Velasco-Elizondo, Ramírez-Estudillo, Fragoso-Saavedra, Pérez-Almeida, Hernández, Melgoza-González, Hinojosa-Trujillo, Mercado-Uriostegui, Mejía-López, Rivera-Ballesteros and García-Gasca.)

Purpose: During the COVID-19 pandemic, healthcare workers (HCWs) are at a considerable risk of being infected with SARS-CoV-2; among them, HCWs from ophthalmology departments are more prone to develop severe symptoms. In Mexico City, the prevalence of SARS-CoV-2 infection among HCWs is 30%. The present work aims to describe the seroprevalence among HCWs at an Ophthalmological Reference Centre in Mexico City., Methods: A self-report questionnaire, RT-PCR test and detection of serum IgG/IgM antibodies against SARS-CoV-2 were performed among HCWs at the Institute of Ophthalmology "Conde de Valenciana"., Results: A total of 169 HCWs participated in the study. None of the participants declared severe symptoms, and only 15% showed three or more symptoms. The results showed that 32% of the participants were RT-PCR + (54/169), and 20% (35/169) presented IgG antibodies against SARS-CoV-2. Thirteen percent of the RT-PCR + subjects were IgG positive, and 7.6% of the RT-PCR - participants were IgG positive. The presence of three or more symptoms correlated with the presence of IgG antibodies, as well as Ct values of < 32 ( p < 0,05)., Conclusion: Most of the HCW cohort showed mild symptoms, and 69% of the RT-PCR + participants did not show IgG antibodies against SARS-CoV-2. Seroprevalence was significantly associated with the presentation of COVID-19-associated symptoms.

The SARS-CoV-2 virus was detected for the first time in December 2019 in Wuhan, China. Currently, this virus has spread around the world, and new variants have emerged. This new pandemic virus provoked the rapid development of diagnostic tools, therapies and vaccines to control this new disease called COVID-19. Antibody detection by ELISA has been broadly used to recognize the number of persons infected with this virus or to evaluate the response of vaccinated individuals. As the pandemic spread, new questions arose, such as the prevalence of antibodies after natural infection and the response induced by the different vaccines. In Mexico, as in other countries, mRNA and viral-vectored vaccines have been widely used among the population. In this work, we developed an indirect ELISA test to evaluate S1 antibodies in convalescent and vaccinated individuals. By using this test, we showed that IgG antibodies against the S1 protein of SARS-CoV-2 were detected up to 42 weeks after the onset of the symptoms, in contrast to IgA and IgM, which decreased 14 weeks after the onset of symptoms. The evaluation of the antibody response in individuals vaccinated with Pfizer-BioNTech and CanSinoBio vaccines showed no differences 2 weeks after vaccination. However, after completing the two doses of Pfizer-BioNTech and the one dose of CanSinoBio, a significantly higher response of IgG antibodies was observed in persons vaccinated with Pfizer-BioNTech than in those vaccinated with CanSinoBio. In conclusion, these results confirm that after natural infection with SARS-CoV-2, it is possible to detect antibodies for up to 10 months. Additionally, our results showed that one dose of the CanSinoBio vaccine induces a lower response of IgG antibodies than that induced by the complete scheme of the Pfizer-BioNTech vaccine., (© 2021 Wiley-VCH GmbH.)

Introduction: This study evaluated the immune response to a multiepitope recombinant chimeric protein (CHIVAX) containing B- and T-cell epitopes of the SARS-CoV-2 spike's receptor binding domain (RBD) in a translational porcine model for pre-clinical studies. Methods: We generated a multiepitope recombinant protein engineered to include six coding conserved epitopes from the RBD domain of the SARSCoV-2 S protein. Pigs were divided into groups and immunized with different doses of the protein, with serum samples collected over time to determine antibody responses by indirect ELISA and antibody titration. Peptide recognition was also analyzed by Western blotting. A surrogate neutralization assay with recombinant ACE2 and RBDs was performed. Intranasal doses of the immunogen were also prepared and tested on Vietnamese minipigs. Results: When the immunogen was administered subcutaneously, it induced specific IgG antibodies in pigs, and higher doses correlated with higher antibody levels. Antibodies from immunized pigs recognized individual peptides in the multiepitope vaccine and inhibited RBD-ACE2 binding for five variants of concern (VOC). Comparative antigen delivery methods showed that both, subcutaneous and combined subcutaneous/intranasal approaches, induced specific IgG and IgA antibodies, with the subcutaneous approach having superior neutralizing activity. CHIVAX elicited systemic immunity, evidenced by specific IgG antibodies in the serum, and local mucosal immunity, indicated by IgA antibodies in saliva, nasal, and bronchoalveolar lavage secretions. Importantly, these antibodies demonstrated neutralizing activity against SARSCoV-2 in vitro. Discussion: The elicited antibodies recognized individual epitopes on the chimeric protein and demonstrated the capacity to block RBD-ACE2 binding of the ancestral SARS-CoV-2 strain and four VOCs. The findings provide proof of concept for using multiepitope recombinant antigens and a combined immunization protocol to induce a neutralizing immune response against SARS-CoV-2 in the pig translational model for preclinical studies. [ABSTRACT FROM AUTHOR]

The emergence of a new coronavirus that causes COVID-19 has generated multiple consequences that have affected the lives of all human beings, imposing a new normal where social distancing and mobility restrictions have become the norm. This situation has also affected organizations forcing them to create or strengthen strategies to respond to the situation to guarantee their survival and growth, which has made it essential to have full commitment from employees. Structural equations were used to design an instrument that was used with managers and middle managers at 130 Mexican companies. Once reliability and validity were tested and confirmed, the study found that there is a positive and significant relation between organizational strategies applied during the health emergency and employee commitment with the organization. [ABSTRACT FROM AUTHOR]

Background: The development of skills, behaviors and attitudes regarding patient safety is of utmost importance for promoting safety culture for the next generation of health professionals. This study describes our experience of implementing a course on patient safety and quality improvement for fourth year medical students in Mexico during the COVID-19 outbreak. The course comprised essential knowledge based on the patient safety curriculum provided by the WHO. We also explored perceptions and attitudes of students regarding patient safety. Methods: Fourth year medical students completed a questionnaire regarding knowledge, skills, and attitudes on patient safety and quality improvement in medical care. The questionnaire was voluntarily answered online prior to and after the course. Results: In total, 213 students completed the questionnaires. Most students were able to understand medical error, recognize failure and the nature of causation, perform root-cause analysis, and appreciate the role of patient safety interventions. Conversely, a disapproving perspective prevailed among students concerning the preventability of medical errors, utility of reporting systems, just culture and infrastructure (p < 0.05). Conclusion: We found students had a positive perspective concerning learning quality in healthcare and patient safety during our course; nevertheless, their perception of the usefulness of reporting systems to prevent future adverse events and prevent medical errors is uncomplimentary. Medical education should promote error reporting and just culture to change the current perception of medical students. [ABSTRACT FROM AUTHOR]