RESUMEN

Neutralizing antibody-based passive immunotherapy could be an important therapeutic option against COVID-19. Herein, we demonstrate that equines hyper-immunized with chemically inactivated SARS-CoV-2 elicited high antibody titers with a strong virus-neutralizing potential, and F(ab')2 fragments purified from them displayed strong neutralization potential against five different SARS-CoV-2 variants. F(ab')2 fragments purified from the plasma of hyperimmunized horses showed high antigen-specific affinity. Experiments in rabbits suggested that the F(ab')2 displays a linear pharmacokinetics with approximate plasma half-life of 47 h. In vitro microneutralization assays using the purified F(ab')2 displayed high neutralization titers against five different variants of SARS-CoV-2 including the Delta variant, demonstrating its potential efficacy against the emerging viral variants. In conclusion, this study demonstrates that F(ab')2 generated against SARS-CoV-2 in equines have high neutralization titers and have broad target-range against the evolving variants, making passive immunotherapy a potential regimen against the existing and evolving SARS-CoV-2 variants in combating COVID-19.

Asunto(s)

COVID-19 , SARS-CoV-2 , Animales , Anticuerpos Neutralizantes , Anticuerpos Antivirales , COVID-19/terapia , Caballos , Humanos , Fragmentos Fab de Inmunoglobulinas , Fragmentos de Inmunoglobulinas , Conejos

RESUMEN

Inactivated viral preparations are important resources in vaccine and antisera industry. Of the many vaccines that are being developed against COVID-19, inactivated whole-virus vaccines are also considered effective. ß-propiolactone (BPL) is a widely used chemical inactivator of several viruses. Here, we analyze various concentrations of BPL to effectively inactivate SARS-CoV-2 and their effects on the biochemical properties of the virion particles. BPL at 1:2000 (v/v) concentrations effectively inactivated SARS-CoV-2. However, higher BPL concentrations resulted in the loss of both protein content as well as the antigenic integrity of the structural proteins. Higher concentrations also caused substantial aggregation of the virion particles possibly resulting in insufficient inactivation, and a loss in antigenic potential. We also identify that the viral RNA content in the culture supernatants can be a direct indicator of their antigenic content. Our findings may have important implications in the vaccine and antisera industry during COVID-19 pandemic.

Asunto(s)

Antivirales/farmacología , Vacunas contra la COVID-19/química , Propiolactona/farmacología , SARS-CoV-2/efectos de los fármacos , Virión/efectos de los fármacos , Inactivación de Virus/efectos de los fármacos , Animales , Antígenos Virales/química , Antígenos Virales/inmunología , COVID-19/inmunología , COVID-19/prevención & control , Vacunas contra la COVID-19/inmunología , Chlorocebus aethiops , Floculación/efectos de los fármacos , Humanos , Sueros Inmunes/química , ARN Viral/química , ARN Viral/inmunología , SARS-CoV-2/química , SARS-CoV-2/inmunología , Vacunas de Productos Inactivados , Células Vero , Virión/química , Virión/inmunología

RESUMEN

BACKGROUND: From an isolated epidemic, coronavirus disease 2019 has now emerged as a global pandemic. The availability of genomes in the public domain after the epidemic provides a unique opportunity to understand the evolution and spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus across the globe. METHODS: We performed whole-genome sequencing of 303 Indian isolates, and we analyzed them in the context of publicly available data from India. RESULTS: We describe a distinct phylogenetic cluster (Clade I/A3i) of SARS-CoV-2 genomes from India, which encompasses 22% of all genomes deposited in the public domain from India. Globally, approximately 2% of genomes, which to date could not be mapped to any distinct known cluster, fall within this clade. CONCLUSIONS: The cluster is characterized by a core set of 4 genetic variants and has a nucleotide substitution rate of 1.1 × 10-3 variants per site per year, which is lower than the prevalent A2a cluster. Epidemiological assessments suggest that the common ancestor emerged at the end of January 2020 and possibly resulted in an outbreak followed by countrywide spread. To the best of our knowledge, this is the first comprehensive study characterizing this cluster of SARS-CoV-2 in India.

RESUMEN

OBJECTIVES: To compare the efficacy of topical antifungal agents, Sertaconazole and Clotrimazole in Tinea corporis patients. MATERIALS AND METHODS: A total of 60(n=60) patients were included in the study. They were divided into two groups of 30 patients each. First group included patients treated with topical Sertaconazole as test drug whereas the second group constituted patients treated with topical Clotrimazole as standard drug. The patients were advised to apply the drug on affected area twice daily for three weeks. The parameters like erythema, scaling, itching, margins and size of the lesion and KOH mount were taken for the assessment of efficacy. This was an open labelled study and patients were followed up every week for three weeks. RESULTS: The total score included all grades in erythema, itching, scaling, margins and size of lesion and KOH mount. There was significant reduction in erythema (p<0.02) and highly significant reduction in scaling (p<0.001), itching (p<0.001) and margins of lesion (p<0.001) among Sertaconazole group. The mean difference and the standard deviation of total scores for Clotrimazole were 7.20 and 1.69 and for Sertaconazole group 8.80 and 1.52 respectively. The p-value on application of students unpaired t- test was p<0.001 (Highly significant). CONCLUSION: From the present study, it can be concluded that topical Sertaconazole shows better improvement in the clinical parameters than topical Clotrimazole within a span of three weeks in the treatment of T corporis.

RESUMEN

Steven-Johnson syndrome may be considered as a cytotoxic immune reaction to drugs, infections etc. This is a case report of Steven-Johnson syndrome due to an ayurvedic preparation which was used in the treatment of mental retardation in a young girl.