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Biopharmaceutical manufacturing processes may include a low pH treatment step as a means of inactivating enveloped viruses. Small scale virus clearance studies are routinely performed using model enveloped viruses such as murine leukemia virus to assess inactivation at the pH range used in the downstream manufacturing process. Further, as a means of bioburden reduction, chromatography resins may be cleaned and stored using sodium hydroxide and this can also inactivate viruses. The susceptibility of SARS-CoV-2 and SARS-CoV to low pH conditions using protein A eluate derived material from a monoclonal antibody production process as well as high pH cleaning conditions was addressed. SARS-CoV-2 was effectively inactivated at pH 3.0, moderately inactivated at pH 3.4, but not inactivated at pH 3.8. Low pH was less effective at inactivating SARS-CoV. Both viruses were inactivated at a high pH of ca.13.4. These studies provide important information regarding the effectiveness of viral clearance and inactivation steps of novel coronaviruses when compared to other enveloped viruses., (Copyright © 2024 International Alliance for Biological Standardization. Published by Elsevier Ltd. All rights reserved.)

Objective: This study aimed to determine the duration of SARS-CoV-2 clearance in persons in Ghana. The research question was whether the duration of virus clearance in Ghana matched the 14 days recommended by the World Health Organization (WHO); this had direct implications for transmission, which was key in managing the COVID-19 pandemic., Design: This was a retrospective analytical study., Setting: All facilities that submitted clinical specimens to Noguchi Memorial Institute for Medical Research (NMIMR) for SARS-CoV-2 diagnosis between March to June 2020 were included in the study., Interventions: Samples from 480 persons who tested positive for SARS-CoV-2 by RT-PCR from March to June 2020 at NMIMR and submitted at least two follow-up samples were retrospectively analysed. Individuals with two consecutive negative RT-PCR retesting results were considered to have cleared SARS-CoV-2., Results: The median time from the initial positive test to virus clearance was 20 days (IQR: 5-56 days). This was six days longer than the WHO-recommended 14 days, after which infected persons could be de-isolated. Sputum and nasopharyngeal swabs proved more sensitive for detecting viral RNA as the infection progressed. At a significance level of 0.05, age and sex did not seem to influence the time to SARS-CoV-2 clearance., Conclusions: The median time to SARS-CoV-2 clearance in this study was 20 days, suggesting that SARS-CoV-2 infected persons in Ghana take longer to clear the virus. This finding calls for further investigations into whether patients who remain PCR positive continue to be infectious and inform isolation practices in Ghana., Funding: The study was supported by the Ministry of Health/ Ghana Health Service through the provision of laboratory supplies, the US Naval Medical Research Unit #3, the World Health Organization, the Jack Ma Foundation and the Virology Department of Noguchi Memorial Institute for Medical Research, University of Ghana. Research projects within Noguchi Memorial Institute for Medical Research contributed reagents and laboratory consumables. However, the authors alone are responsible for the contents of this manuscript., Competing Interests: Conflict of interest: None declared, (Copyright © The Author(s).)

The impact of corticosteroid treatment on virological course of coronavirus disease 2019 (COVID-19) patients remains unclear. This study aimed to explore the association between corticosteroid and viral clearance in COVID-19. The clinical data of COVID-19 patients from 10 hospitals of Jiangsu, China, were retrospectively collected. Cox regression and Kaplan-Meier analysis were used to analyze the adverse factors of virus clearance. Of the 309 COVID-19 patients, eighty-nine (28.8%) patients received corticosteroid treatment during hospitalization. Corticosteroid group showed higher C-reactive protein (median 11.1 vs. 7.0 mg/l, P = 0.018) and lower lymphocytes (median 0.9 vs. 1.4 × 10 9 /l, P < 0.001) on admission. Fever (93.3% vs. 65.0%, P < 0.001) and cough (69.7% vs. 57.3%, P = 0.043) were more common in corticosteroid group. The proportions of patients with severe illness (34.8% vs. 1.8%, P < 0.001), respiratory failure (25.8% vs. 1.4%, P < 0.001), acute respiratory distress syndrome (4.5% vs. 0%, P = 0.002), and admission to ICU (20.2% vs. 0.9%, P < 0.001) were significantly higher in corticosteroid group than non-corticosteroid group. The duration of virus clearance (median 18.0 vs. 16.0 days, P < 0.001) and hospitalization (median 17.0 vs. 15.0 days, P < 0.001) were also significantly longer in corticosteroid group than non-corticosteroid group. Treated with corticosteroid (Hazard ratio [HR], 0.698; 95% confidence interval [CI], 0.512 to 0.951; P = 0.023) was an adverse factor of the clearance of SARS-CoV-2, especially for male patients (HR, 0.620; 95% CI, 0.408 to 0.942; P = 0.025). The cumulative probability of SARS-CoV-2 clearance was lower in corticosteroid group (P < 0.001). Corticosteroid treatment may delay the SARS-CoV-2 clearance of COVID-19 patients and should be used with cautions., (Copyright © 2020. Published by Elsevier B.V.)

COVID-19 has emerged as a global pandemic, challenging the world's economic and health systems. Human oral microbiota comprises the second largest microbial community after the gut microbiota and is closely related to respiratory tract infections; however, oral microbiomes of patients who have recovered from COVID-19 have not yet been thoroughly studied. Herein, we compared the oral bacterial and fungal microbiota after clearance of SARS-CoV-2 in 23 COVID-19 recovered patients to those of 29 healthy individuals. Our results showed that both bacterial and fungal diversity were nearly normalized in recovered patients. The relative abundance of some specific bacteria and fungi, primarily opportunistic pathogens, decreased in recovered patients (RPs), while the abundance of butyrate-producing organisms increased in these patients. Moreover, these differences were still present for some organisms at 12 months after recovery, indicating the need for long-term monitoring of COVID-19 patients after virus clearance. [ABSTRACT FROM AUTHOR]

aimed to investigate the correlation between obesity and virus persistence in patients with COVID-19. Design and Methods: A total of 57 patients with laboratory-confirmed COVID-19 were admitted to two clinical centers, and data were analyzed retrospectively. Among them, 18 patients with body mass index (BMI) ≥ 25 kg/m2 were diagnosed with obesity, and dynamics of viral replication were compared. Results: Eighteen patients were diagnosed with obesity. The correlations between BMI and white blood cell, C-reactive protein, and cycle threshold (Ct) values of ORF1ab were not significant (all P > 0.05). On day 7 after admission, virus clearance was achieved in 13 (33.3%) patients with BMI < 25 kg/m2 and 5 (27.8%) patients with BMI ≥ 25 kg/m2 (χ2 = 0.176, P =0.68). On day 14, the RNA tests were negative in 37 (94.9%) patients with BMI < 25 kg/m2 and 13 (72.2%) patients with BMI ≥ 25 kg/m2 (χ2 = 5.865, P = 0.03). Multivariable analysis showed that only BMI ≥ 25 kg/m2 (P = 0.02) was the independent risk factor for virus clearance on day 14. Conclusion: Obesity may affect the clearance of SARS-CoV-2, and BMI should be assessed in patients with COVID-19, although they are not seriously ill. [ABSTRACT FROM AUTHOR]