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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.

Introduction As a homologue of the angiotensin-converting enzyme (ACE), angiotensin-converting enzyme 2 (ACE2) has been identified as the main receptor for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) invasion. We aimed to investigate the role of serum ACE in predicting the coronavirus disease 2019 (COVID-19) disease progression and the underlying mechanisms. Methods We retrospectively enrolled 120 patients with confirmed COVID-19 who underwent serum ACE detection on admission. The clinical characteristics and laboratory findings during hospitalization were evaluated dynamically to identify the potential risk factors for disease progression. Results ACE level was demonstrated as one of the independent risk factors. Patients with ACE level ≤ 33.5 U/L showed a higher cumulative virus RNA detection rate, elevated pro-inflammatory mediators levels, declined lymphocyte count, and decreased SARS-CoV-2-specific antibodies than those with ACE level > 33.5 U/L. Conclusion Lower serum ACE levels in relation to delayed virus elimination, hyperinflammatory condition, and impaired host antiviral immune responses contribute to disease progression of COVID-19.

Xiujun Zhang,1,2 Bin Lin,3 Gang Yang,4 Longgen Liu,1,2 Jianchun Lu,1,2 Zhaohui Lu,4 Yuan Xue1,2 1Institute of Hepatology, The Third People’s Hospital of Changzhou, Changzhou, People’s Republic of China; 2Department of Liver Diseases, The Third People’s Hospital of Changzhou, Changzhou, People’s Republic of China; 3Department of Infectious Diseases, The First People’s Hospital of Jintan, Changzhou, People’s Republic of China; 4Department of Respiratory Diseases, The Second People’s Hospital of Wuhu, Wuhu, People’s Republic of ChinaCorrespondence: Zhaohui Lu; Yuan Xue Email lzh1980222@163.com; xueyuan80908@163.comObjective: The present study 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.Keywords: SARS-CoV2, COVID-19, body mass index, obesity, virus clearance

Continuous virus inactivation (VI) has received little attention in the efforts to realize fully continuous biomanufacturing in the future. Implementation of continuous VI must assure a specific minimum incubation time, typically 60 min. To guarantee the minimum incubation time, we implemented a packed bed continuous viral inactivation reactor (CVIR) with narrow residence time distribution (RTD) for low pH incubation. We show that the RTD does not broaden significantly over a wide range of linear flow velocities—which highlights the flexibility and robustness of the design. Prolonged exposure to acidic pH has no impact on bed stability, assuring constant RTD throughout long term operation. The suitability of the packed bed CVIR for low pH inactivation is shown with two industry‐standard model viruses, that is xenotropic murine leukemia virus and pseudorabies virus. Controls at neutral pH showed no system‐induced VI. At low pH, significant VI is observed, even after only 15 min. Based on the low pH inactivation kinetics, the continuous process is equivalent to traditional batch operation. This study establishes a concept for continuous low pH inactivation and, together with previous reports, highlights the versatility of the packed bed reactor for continuous VI, regardless of the inactivation method., Virus inactivation is essential for product safety however its implementation in continuous mode remains a challenge while the biopharma industry aims at continuous biomanufacturing. This work describes the full viral inactivation of two model viruses by low pH using a packed‐bed reactor with narrow residence time distribution as incubation reactor.This novel approach enables an truly continuous operation while being as effective as the current batch approach.

Inorganic materials can provide a set of tools to decontaminate solid, liquid or air containing viral particles. The use of disinfectants can be limited or not practical in scenarios where continuous cleaning is not feasible. Physicochemical differences between viruses raise the need for effective formulations for all kind of viruses. In the present work we describe two types of antimicrobial inorganic materials: i) a novel soda-lime glass (G3), and ii) kaolin containing metals nanoparticles (Ag or CuO), as materials to disable virus infectivity. Strong antiviral properties can be observed in G3 glass, and kaolin-containing nanoparticle materials showing a reduction of viral infectivity close to 99%. in the first 10 ​min of contact of vesicular stomatitis virus (VSV). A potent virucidal activity is also present in G3 and kaolin containing Ag or CuO nanoparticles against all kinds of viruses tested, reducing more than 99% the amount of HSV-1, Adenovirus, VSV, Influenza virus and SARS-CoV-2 exposed to them. Virucidal properties could be explained by a direct interaction of materials with viruses as well as inactivation by the presence of virucidal elements in the material lixiviates. Kaolin-based materials guarantee a controlled release of active nanoparticles with antiviral activity. Current coronavirus crisis highlights the need for new strategies to remove viruses from contaminated areas. We propose these low-cost inorganic materials as useful disinfecting antivirals in the actual or future pandemic threats., Graphical abstract Image 1

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 × 109/l, P

Background The outbreak of COVID‐19, caused by SARS‐CoV‐2, started in December 2019, Wuhan, China. We aimed to figure out the time‐point and duration of using antiviral drugs for receiving the maximal effects in patients with COVID‐19. Methods In this study, we enrolled 129 confirmed COVID‐19 mild to moderate patients who had been treated with antiviral drugs during their hospitalization in Wuhan Union Hospital China. The patients were divided into early antiviral treatment group and late antiviral treatment group. The demographic data, laboratory tests, the virus clearance time, chest computed tomography (CT) scans, etc. were extracted, calculated and compared between two groups. Results Our data showed that the median time from illness onset to initiation of antiviral treatment was 6 days in all patients. The group with early antiviral treatment demonstrated 7 days shorter in the virus clearance time when compared to the group with late antiviral treatment. After virus clearance, the group with early antiviral treatment showed milder illness than the group with late antiviral treatment. Conclusions Early antiviral treatment could effectively shorten the virus clearance time, and prevent the rapid progression of COVID‐19. Therefore, the COVID‐19 patients should receive combined therapies with antiviral treatment at early stage. This article is protected by copyright. All rights reserved.

We designed small‐scale virus filtration models to investigate the impact of the extended process times and dynamic product streams present in continuous manufacturing. Our data show that the Planova 20N and BioEX virus filters are capable of effectively removing bacteriophage PP7 (>4 log) when run continuously for up to 4 days. Additionally, both Planova 20N and BioEX filters were able to successfully process a mock elution peak of increased protein, salt, and bacteriophage concentrations with only an increase in filtration pressure observed during the higher protein concentration peak. These experiments demonstrated that small‐scale viral clearance studies can be designed to model a continuous virus filtration step with specific process parameters.

The RNA interference (RNAi) pathway directs an important antiviral immunity mechanism in plants and invertebrates. Recently, we and others have demonstrated that the antiviral RNAi response is also conserved in mammals, at least to five distinct RNA viruses, including Zika virus (ZIKV). ZIKV may preferentially infect neuronal progenitor cells (NPCs) in the developing foetal brain. Ex vivo ZIKV infection induces RNAi-mediated antiviral response in human NPCs, but not in the more differentiated NPCs or somatic cells. However, litter is known about the in vivo property or function of the virus-derived small-interfering RNAs (vsiRNAs) targeting ZIKV. Here we report a surprising observation: different from ex vivo observations, viral small RNAs (vsRNAs) targeting ZIKV were produced in vivo upon infection in both central neuron system (CNS) and muscle tissues. In addition, our findings demonstrate the production of canonical vsiRNAs in murine CNS upon antiviral RNAi activation by Sindbis virus (SINV), suggesting the possibility of antiviral immune strategy applied by mammals in the CNS.

After the transmission of human viruses through plasma derivatives had been recognized in the early 1980s, virus inactivation and then removal steps have been implemented into their manufacturing processes. These measures have kept plasma derivatives safe ever since and have also served as a barrier against more recently emerging viruses. Given the success of these interventions, they have also been embedded into the manufacturing processes for cell‐derived biological medicinal products. The most effective inactivation process for lipid‐enveloped viruses is treatment by detergents or combinations of solvents and detergents, and thus, these processes have been almost universally adopted. One of the most widely used detergents, Triton X‐100, has recently raised environmental concerns because one of its degradation products possesses hormone‐like (estrogen‐mimetic) activity that may act on wildlife. Consequently, use of the chemical in the European Union will ultimately be prohibited. The current study was conducted to establish an environmentally friendly detergent alternative to Triton X‐100 with fully equivalent efficacy in biotechnological use. A newly synthesized compound, named Nereid, as well as Triton X‐100 reduced, seem to satisfy these requirements, and thus may be suitable replacements for Triton X‐100.

Turoctocog alfa is a B-domain-truncated recombinant factor VIII protein produced in a Chinese hamster ovary (CHO) cell line. The aim of this study was to evaluate the virus clearance capacity and robustness of the turoctocog alfa purification process. Virus clearance evaluation studies were conducted utilising a scaled-down version of the manufacturing process. Total virus clearance was evaluated using the ecotropic murine leukaemia virus (eMuLV) as a model for non-infectious retrovirus-like particles (RVLPs) and certain enveloped viruses. Other viruses utilised included: infectious bovine rhinotracheitis (IBRV), minute virus of mice (MVM), bovine enterovirus (BEV) and Reo-3 virus (Reo-3). Robust clearance of all model viruses was demonstrated with either new or reused resins. Overall, virus reduction factors were: >18.0 log10 (eMuLV); 11.0 log10 (MVM); >11.8 log10 (Reo-3; >5.0 log10 using nanofiltration); >15.3 log10 (BEV) and >12.7 log10 (IBRV). Taken together, these values demonstrate that the purification process for turoctocog alfa effectively removes a range of enveloped and non-enveloped viruses of different physicochemical properties and sizes.

Duck hepatitis A virus 1 (DHAV-1) infection in mature ducks has previously been proposed as a small-animal model for human hepatitis A. However, basic research on the outcome of DHAV-1 infection in mature ducks is limited. Here, we examined the course of viremia, the characteristics of antibody responses, and the profiles of plasma cytokines in mature ducks infected with DHAV-1. During the course of infection, the viremia was detectable soon after infection and persisted for 196 days, however, the ducks presented as clinically asymptomatic. Specific and timely immunoglobulin G (IgG), IgM, and IgA1 responses were elicited. At the same time, extensive inhibition of viral replication was observed with increasing IgG concentration. With respect to pattern-recognition receptors, TLR-7 was mainly involved in triggering the innate defense against the DHAV-1 infection. In addition, plasma immune analytes were measured and were determined to have bidirectional roles in virus clearance. It was concluded that DHAV-1 spreads quickly in blood. The spontaneous clearance of DHAV-1 during asymptomatic infection in mature ducks depends on the cooperation of timely antibody responses and alert innate immune responses. Moreover, the delayed clearance may be associated with a weak interferon-γ-producing CD8+ T cell response. This study allows us to reveal the mechanism of clearance and persistence of DHAV-1 infection in mature ducks. We anticipate that it will provide a basis for future studies focused on defining the nature mechanisms involved in the clearance and persistence of human hepatitis virus.

Infectious bursal disease (IBD) is a highly contagious disease of chickens which leads to immunosuppression. In our previous study it was demonstrated that, possibly, CD4(+) and CD8(+) T cells may employ perforin and granzyme-A pathway for the clearance of IBDV-infected bursal cells. In this study, we evaluated the cytotoxic T cell responses involving two independently functioning but complementary mechanisms: Fas-Fas ligand and perforin-granzyme pathways in IBDV-infected chickens. As demonstrated previously, infection of chickens with IBDV was accompanied by influx of CD8(+) T cells in the bursa and spleen. There was an upregulation in the gene expression of cytolytic molecules: Fas and Fas ligand (FasL), perforin (PFN) and granzyme-A (Gzm-A) in bursal and in the splenic tissues of IBDV inoculated chickens. Additionally, for the first time, we detected Fas, Fas ligand, Caspase-3 and PFN producing CD8(+) T cells in the bursa and spleen of IBDV-infected chickens. The infiltration and activation of CD8(+) T cells was substantiated by the detection of Th1 cytokine, IFN-γ. These data suggest that T cells may be involved in the clearance of virus from the target organ bursa and peripheral tissues such as spleen. The findings of these studies provide new insights into the pathogenesis of IBD and provide mechanistic evidence that the cytotoxic T cells may act through both Fas-FasL and perforin-granzyme pathways in mediating the clearance of virus-infected cells.

Background Epidemiologic evidence links tobacco smoke and increased risk for influenza in humans, but the specific host defense pathways involved are unclear. Objective We developed a model to examine influenza-induced innate immune responses in humans and test the hypothesis that exposure to cigarette smoke alters nasal inflammatory and antiviral responses to live attenuated influenza virus (LAIV). Methods This was an observational cohort study comparing nasal mucosal responses to LAIV among young adult active smokers (n = 17), nonsmokers exposed to secondhand smoke (SHS; n = 20), and unexposed controls (n = 23). Virus RNA and inflammatory factors were measured in nasal lavage fluids (NLF) serially after LAIV inoculation. For key end points, peak and total (area under curve) responses were compared among groups. Results Compared with controls, NLF interleukin-6 (IL-6) responses to LAIV (peak and total) were suppressed in smokers. Virus RNA in NLF cells was significantly increased in smokers, as were interferon-inducible protein 10:virus ratios. Responses in SHS-exposed subjects were generally intermediate between controls and smokers. We observed significant associations between urine cotinine and NLF IL-6 responses (negative correlation) or virus RNA in NLF cells (positive correlation) for all subjects combined. Conclusions Nasal inoculation with LAIV results in measurable inflammatory and antiviral responses in human volunteers, thus providing a model for investigating environmental effects on influenza infections in humans. Exposure to cigarette smoke was associated with suppression of specific nasal inflammatory and antiviral responses, as well as increased virus quantity, after nasal inoculation with LAIV. These data suggest mechanisms for increased susceptibility to influenza infection among persons exposed to tobacco smoke.

Introduction and aim. Hepatitis C virus (HCV) infection is a global medical problem. HLA –DRB1 alleles have an important role in immune response against HCV. The aim of this study is to clarify the contribution of HLA –DRB1 alleles in HCV susceptibility in a multicentre family-based study. Material and methods. A total of 162 Egyptian families were recruited in this study with a total of 951 individuals (255 with chronic hepatitis C (CHC), 588 persons in the control group(-ve household contact to HCV) and 108 persons who spontaneously cleared the virus (SVC). All subjects were genotyped for HLA -DRB1 alleles by SSP-PCR and sequence based typing (SBT) methods. Results. The carriage of alleles 3:01:01 and 13:01:01 were highly significant in CHC when compared to that of control and SVC groups [OR of 3 family = 5.1289, PC (Bonferroni correction ) = 0.0002 and 5.9847, PC = 0.0001 and OR of 13 family = 4.6860, PC = 0.0002 and OR = 6.5987, PC = 0.0001 respectively]. While DRB1*040501, DRB1*040101, DRB1*7:01:01 and DRB1*110101 alleles were more frequent in SVC group than CHC patients (OR = 0.4052, PC = 0.03, OR: OR = 0.0916, PC = 0.0006, OR = 0.1833, PC = 0.0006 and OR = 0.4061, PC = 0.0001 respectively). Conclusions. It was concluded that among the Egyptian families, HLA- DRB1*030101, and DRB1*130101 alleles associated with the risk of progression to CHC infection, while DRB1*040101, DRB1*040501, DRB1*7:01:01and DRB1*110101 act as protective alleles against HCV infection.

The severe acute respiratory syndrome (SARS) epidemic started in late 2002 and swiftly spread across 5 continents with a mortality rate of around 10%. Although the epidemic was eventually controlled through the implementation of strict quarantine measures, there continues a need to investigate the SARS coronavirus (SARS-CoV) and develop interventions should it re-emerge. Numerous studies have shown that neutralizing antibodies against the virus can be found in patients infected with SARS-CoV within days upon the onset of illness and lasting up to several months. In contrast, there is little data on the kinetics of T cell responses during SARS-CoV infection and little is known about their role in the recovery process. However, recent studies in mice suggest the importance of T cells in viral clearance during SARS-CoV infection. Moreover, a growing number of studies have investigated the memory T cell responses in recovered SARS patients. This review covers the available literature on the emerging importance of T cell responses in SARS-CoV infection, particularly on the mapping of cytotoxic T lymphocyte (CTL) epitopes, longevity, polyfunctionality and human leukocyte antigen (HLA) association as well as their potential implications on treatment and vaccine development.

We subjected 302 archival samples (150 squamous cell carcinomas [SCCs] and 152 cervical intraepithelial neoplasia [CIN] lesions) to immunohistochemical staining with extracellular signal-regulated kinase-1 (ERK1) antibody and human papillomavirus (HPV) testing with 3 primer sets. Follow-up data were available for all SCC cases and 67 CIN cases. High-risk (HR) HPV types were associated with CIN (odds ratio [OR], 19.12; 95% confidence interval [CI], 2.31-157.81) and SCC (OR, 27.25; 95% CI, 3.28226.09). There was a significant linear relationship between lesion grade and ERK1 staining intensity (P = .0001). ERK1 staining was a 100% specific indicator of CIN, with a 100% positive predictive value, but a poor predictor of HR HPV. ERK1 expression did not predict clearance or persistence of HR HPV after CIN treatment. ERK1 staining did not significantly predict survival in cervical cancer in univariate (P = .915) or multivariate analysis. After adjustment for HR HPV, stage, age, and tumor grade in the Cox regression model, only stage (P = .0001) and age (P = .002) remained independent prognostic factors. ERK1 expression seems to be an early marker of cervical carcinogenesis. ERK1 overexpression is not a specific marker of HR-HPV in CIN and cervical cancer, nor does it predict virus clearance after CIN treatment or disease outcome in cervical cancer.