Virus Activity Research Articles

Multiple intermediates in the detergent-induced fusion of lipid vesicles

Detergent-induced vesicle interactions, critical for applications including virus inactivation, varies according to the detergent type and membrane composition, but the underlying mechanistic details remain underexplored. Here, we use a lipid mixing assay based on Förster resonance energy transfer (FRET), and single-vesicle characterization approaches to identify that sub-micron-sized vesicles are induced to fuse by the non-ionic detergent Triton-X-100. We demonstrate that the process is a multi-step mechanism, characterized by discrete values of FRET efficiency between membrane-embedded fluorophores, and involves permeabilization, vesicle docking, hemi-fusion and full lipid mixing at sub-solubilizing detergent concentrations. We also dissect the kinetics of vesicle fusion to surface-tethered vesicles using a label-free quartz-crystal microbalance with dissipation monitoring approach, opening a platform for biotechnology applications. The presented strategies provide mechanistic insight into the dynamics of vesicle fusion and have implications for applications including drug delivery and sensor development where transport and manipulation of encapsulated cargo is essential.

HIV-1 diversity in viral reservoirs obtained from circulating T-cell subsets during early ART and beyond.

Even during extended periods of effective immunological control, a substantial dynamic of the viral genome can be observed in different cellular compartments in HIV-1 positive individuals, indicating the persistence of active viral reservoirs. To obtain further insights, we studied changes in the proviral as well as in the viral HIV-1 envelope (Env) sequence along with transcriptional, translational and viral outgrowth activity as indicators for viral dynamics and genomic intactness. Our study identified distinct reservoir patterns that either represented highly sequence-diverse HIV-1 populations or only a single / few persisting virus variants. The single dominating variants were more often found in individuals starting ART during early infection phases, indicating that early treatment might limit reservoir diversification. At the same time, more sequence-diverse HIV reservoirs correlated with a poorer immune status, indicated by lower CD4 count, a higher number of regimen changes and more co-morbidities. Furthermore, we noted that in T-cell populations in the peripheral blood, replication-competent HIV-1 is predominantly present in Lymph node homing TN (naïve) and TCM (central memory) T cells. Provirus genomes archived in TTM (transitional memory) and TEM (effector memory) T cells more frequently tended to carry inactivating mutations and, population-wise, possess changes in the genetic diversity. These discriminating properties of the viral reservoir in T-cell subsets may have important implications for new early therapy strategies, underscoring the critical role of early therapy in preserving robust immune surveillance and constraining the viral reservoir.

Buffer system improves the removal of host cell protein impurities in monoclonal antibody purification.

Polysorbates (PS) are commonly used as stabilizers of biopharmaceuticals such as monoclonal antibodies (mAbs). However, they are prone to chemical and enzymatic degradation. The latter can be caused by residual host cell proteins (HCPs) in the drug substance. Degradation affects the functionality of the PS surfactant which can lead to formation of particles. An increasing number of publications describe enzymatic PS degradation. Significant efforts have been made to characterize HCP removal during Downstream Processing (DSP) of mAbs and to develop mitigation strategies. Here we describe the use of glycine buffer for acidic elution in Protein A affinity chromatography compared to acetate buffer, which is more commonly used in the biopharmaceutical industry. Increased turbidity was observed during pH re-adjustment after low pH virus inactivation when using glycine buffer. Analytical data suggests that this turbidity is caused by the formation of precipitates which include HCP and DNA impurities. Additionally, as a zwitterion, glycine does not contribute to conductivity; this further enhances HCP removal during anion-exchange flow-through chromatography. Although glycine is well known as a possible elution buffer for Protein A affinity chromatography, its positive impact on HCP removal and PS stability have not yet been described in literature.

A Model-Based Estimation of RSV-Attributable Incidence of Hospitalizations and Deaths in Italy Between 2015 and 2019.

Respiratory syncytial virus (RSV) incidence is known to be underestimated in adults due to its infrequent diagnostic testing and lower sensitivity of single nasal/nasopharyngeal swab PCR testing outside of the early childhood period. RSV can trigger acute cardiac events as well as cause respiratory disease. Consequently, we used a model-based study to estimate RSV-attributable hospitalization and mortality incidence among adults in Italy between 2015 and 2019. Through a database predisposed by CREA Sanità, by extracting monthly data from the Italian hospitalization collection data of the Ministry of Health and the Italian National Institute of Statistics (ISTAT) data (mortality), we estimated yearly RSV-attributable incidence of events for different cardiorespiratory outcomes. We used a quasi-Poisson regression model, which accounted for periodic and aperiodic time trends and viral activity proxies. The yearly RSV-attributable cardiorespiratory hospitalization incidence increased with age and was highest among adults aged≥75 years (1064-1527 cases per 100,000 person-years). Similarly, the RSV-attributable cardiorespiratory mortality rate was highest among persons aged≥75 years (59-85 deaths per 100,000 person-years). Incidence rates for RSV-attributable hospitalizations and RSV-attributable mortality were on average 2-3 times higher for cardiorespiratory than respiratory disease alone. Incidence rate based on RSV-specific ICD codes only were 405-1729 times lower than modeled estimates accounting for untested events. RSV causes a substantial disease burden among adults in Italy and contributes to both respiratory and cardiovascular conditions. Our results emphasize the need for effective RSV prevention strategies, particularly among older adults.

The impact of sex on HIV immunopathogenesis and therapeutic interventions.

Globally, the majority of people living with HIV are women or girls, but they have been a minority of participants in clinical trials and observational studies of HIV. Despite this underrepresentation, differences in the pathogenesis of HIV have been observed between men and women, with contributions from both gender- and sex-based factors. These include differences in the risk of HIV acquisition, in viral load set point and immune activation in responses to viremia, and differences in HIV reservoir maintenance. These differences obligate adequate study in both males and females in order to optimize treatments, but also provide a powerful leverage point for delineating the mechanisms of HIV pathogenesis. The shifts in exposure to sex steroid hormones across a lifespan introduce additional complexity, which again can be used to focus on either genetic or hormonal influences as the driver of an outcome. In this Review, we discuss consistent and reproducible differences by sex across the spectrum of HIV, from acquisition through pathogenesis, treatment, and cure, and explore potential mechanisms and gaps in knowledge.

Analysis of Swallow Nest Nitrite Levels and Export Volume Projections: A Statistical Approach to Quality Improvement and Global Market Development

The global SARS-CoV-2 pandemic is impacting public health and living systems. Edible Bird's Nest (EBN), one of the variants of Swallow's Nest (SBW), is recognized as a medicinal food. The potential of SBW as a therapeutic agent is gaining attention due to its ability to inhibit viral hemagglutination activity. This study provides information on the prediction of SBW demand in the coming year so that it can contribute to determining Indonesia's SBW export performance. Net weight data (tons) of SBW export time series were obtained for 10 years from 2012 to 2022 in 10 countries, namely: Hong Kong, China, Singapore, USA, Vietnam, Canada, Taiwan, Thailand, Japan, and Cambodia, combined with laboratory examination on nitrite levels conducted at the Surabaya Agricultural Quarantine Center, Indonesia. This study shows the minimum limit on nitrite levels in SBW exports and the need for SBW exports in the next four years. One of the requirements for SBW exports is the minimum limit of nitrite levels. The ARIMA method has been implemented to forecast SBW export demand in 10 countries for the next four years. SBW export demand in the next four years is expected to decline. The findings make a significant contribution as a source of information for decision-makers involved in SBW export activities.

Conjugation of anti-HIV gp41 monoclonal antibody to a drug capable of targeting resting lymphocytes produces an effective cytotoxic anti-HIV immunoconjugate.

HIV-infected cells persisting in the face of suppressive antiretroviral therapy are the barrier to curing infection. Cytotoxic immunoconjugates targeted to HIV antigens on the cell surface may clear these cells. We showed efficacy in mouse and macaque models using immunotoxins, but immunogenicity blunted the effect. As an alternative, we propose antibody drug conjugates (ADCs), as used in cancer immunotherapy. In cancer, the target is a dividing cell, whereas it may not be in HIV. We screened cytotoxic drugs on human primary cells and cell lines. An anthracycline derivative, PNU-159682 (PNU), was highly cytotoxic to both proliferating and resting cells. Human anti-gp41 mAb 7B2 was conjugated to ricin A chain or PNU. The conjugates were tested in vitro for cytotoxic efficacy and anti-viral effect, and in vivo for tolerability. The specificity of killing for both conjugates was demonstrated on Env+ and Env- cells. The toxin conjugate was more potent and killed more rapidly, but 7B2-PNU was effective at levels achievable in patients. The ricin conjugate was well tolerated in mice; 7B2-PNU was toxic when administered intraperitoneally but was tolerated intravenously. We have produced an ADC with potential to target the persistent HIV reservoir in both dividing and non-dividing cells while avoiding immunogenicity. Cytotoxic anti-HIV immunoconjugates may have greatest utility as part of an "activate and purge" regimen, involving viral activation in the reservoir. This is a unique comparison of an immunotoxin and ADC targeted by the same antibody and tested in the same systems.IMPORTANCEHIV infection can be controlled with anti-retroviral therapy, but it cannot be cured. Despite years of therapy that suppresses HIV, patients again become viremic shortly after discontinuing treatment. A long-lived population of memory T cells retain the genes encoding HIV, and these cells secrete infectious HIV when no longer suppressed by therapy. This is the persistent reservoir of HIV infection. The therapies described here use anti-HIV antibodies conjugated to poisons to kill the cells in this reservoir. These poisons may be of several types, including protein toxins (immunotoxins) or anti-cancer drugs (antibody drug conjugates, ADCs). We have previously shown that an anti-HIV immunotoxin had therapeutic effects in animal models, but it elicited an anti-drug immune response. Here, we have prepared an anti-HIV ADC, which would be less likely to provoke an immune response, and show its potential for use in eliminating the persistent reservoir of HIV infection.

STING Agonist Induced Innate Immune Responses Drive Anti-Respiratory Virus Activity In Vitro with Limited Antiviral Efficacy In Vivo.

The emergence of SARS-CoV-2 and seasonal outbreaks of other respiratory viruses highlight the urgent need for broad-spectrum antivirals to treat respiratory tract infections. Stimulator of interferon genes (STING) is a key component of innate immune signaling and plays a critical role in protection of the host against viral infections. Previously the STING agonist diABZI-4, a diamidobenzimidazole-based compound, demonstrated protection against SARS-CoV-2 both in vitro and in vivo. However, its broad-spectrum antiviral activity against other respiratory viruses in human airway epithelial cells, which are the primary targets of these infections, is not well established. In this study, we demonstrated that diABZI-4 stimulated robust innate immune responses protecting lung cells against a wide range of respiratory viruses, including influenza A virus (IAV), common cold coronaviruses, SARS-CoV-2, human rhinovirus (HRV), and human parainfluenza virus. diABZI-4 was highly active in physiologically relevant human airway epithelial tissues grown at the air-liquid interface, blocking replication of IAV, SARS-CoV-2, and HRV in these tissues. Furthermore, treatment of macrophages with diABZI-4 resulted in the secretion of cytokines that protected the primary airway epithelial cells from IAV infection. Despite the promising in vitro pan-antiviral activity, intranasal administration of diABZI-4 in mice provided early, but not sustained, inhibition of IAV replication in the lungs. These data highlight the complexities of the relationship between timing of STING agonist-driven inflammatory responses and viral replication dynamics, emphasizing the development challenge posed by STING agonists as potential therapeutics against respiratory viruses.

Bovine Highly Pathogenic Avian Influenza Virus Stability and Inactivation in the Milk Byproduct Lactose.

The recent incursion of highly pathogenic influenza viruses into dairy cattle opens new insights for influenza virus ecology and its interspecies transmission and may have a significant impact on public health and agriculture. The aim of this study was to determine the stability of a bovine highly pathogenic avian influenza H5N1 virus isolate in the milk byproduct lactose and to evaluate two inactivation methods using industrial procedures. The bovine isolate of the highly pathogenic avian influenza H5N1 virus was stable for 14 days in a concentrated lactose solution under refrigerated conditions. Heat or citric acid treatments successfully inactivated the virus in lactose. This study highlights the persistence of HPAIV in lactose and its efficient inactivation under industrial standards.

PEG-SeNPs as therapeutic agents inhibiting apoptosis and inflammation of cells infected with H1N1 influenza A virus

The rapid variation of influenza challenges vaccines and treatments, which makes an urgent task to develop the high-efficiency and low-toxicity new anti-influenza virus drugs. Selenium is one of the essential trace elements for the human body that possesses a good antiviral activity. In this study, we assessed anti-influenza A virus (H1N1) activity of polyethylene glycol (PEG)-modified gray selenium nanoparticles (PEG-SeNPs) on Madin-Darby Canine Kidney (MDCK) cells in vitro. CCK-8 assay showed that PEG-SeNPs had a protective effect on H1N1-infected MDCK cells. Moreover, PEG-SeNPs significantly reduced the mRNA level of H1N1. TUNEL-DAPI test showed that DNA damage reached a high level but effectively prevented after PEG-SeNPs treatment. Meanwhile, JC-1, Annexin V-FITC and cell cycle assay demonstrated the apoptosis induced by H1N1 was reduced greatly when treated with PEG-SeNPs. Furthermore, the downregulation of p-ATM, p-ATR and P53 protein, along with the upregualation of AKT protein indicated that PEG-SeNPs could inhibit H1N1-induced cell apoptosis through reactive oxygen species (ROS)-mediated related signaling pathways. Finally, Cytokine detection demonstrated PEG-SeNPs inhibited the production of pro-inflammatory factors after infection, including IL-1β, IL-5, IL-6, and TNF-α. To sum up, PEG-SeNPs might become a new potential anti-H1N1 influenza virus drug due to its antiviral and anti-inflammatory activity.

Aptamer-based Strategies for COVID-19 Detection and Treatment: A Systematic Review Study

Background: Aptamer-based strategies have emerged as promising tools for the detection and treatment of COVID-19, offering advantages such as high specificity, sensitivity, and versatility. This systematic review aims to evaluate the effectiveness and innovation of aptamer-based approaches for COVID-19 detection and treatment. Methods: Following the guidelines of the Cochrane Handbook for Systematic Reviews and the PRISMA 2020 guidelines, a systematic search was conducted across multiple databases up to 2024. The search included studies that utilized aptamers for the diagnosis or therapy of COVID-19. Screening and selection of studies were performed independently by two reviewers, with any disagreements resolved by a third reviewer. Data were extracted regarding study characteristics, aptamer details, and outcomes. Results: In our systematic review, 98 studies from an initial pool of 1541 records met the inclusion criteria for analysis. Aptamers, single-stranded DNA or RNA molecules with unique threedimensional (3D) structures, were extensively explored for COVID-19 detection and treatment. Various aptamer-based assays, including electrochemical sensors, surface plasmon resonance (SPR) biosensors, and lateral flow assays, demonstrated high sensitivity and specificity in detecting SARSCoV- 2 in clinical samples such as saliva, nasal swabs, and wastewater. Several aptamer structures targeting viral proteins like the spike and nucleocapsid proteins were employed. Nucleic Acid Amplification Techniques (NAATs) utilizing aptamers, such as Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-based and Loop-mediated Isothermal Amplification (LAMP) assays, showed exceptional sensitivity in detecting viral genetic material. Aptamer-based therapeutic approaches showed potential by blocking viral protein activity or serving as delivery vehicles for therapeutic agents like small interfering RNAs (siRNAs). Despite their advantages, aptamer technologies face limitations such as susceptibility to nuclease degradation and rapid renal clearance, highlighting the need for further optimization. Conclusion: Aptamer-based strategies present promising avenues for COVID-19 detection and treatment. These approaches offer advantages such as high sensitivity, specificity, and rapid detection, making them valuable tools in combating the COVID-19 pandemic. Further research and development are warranted to optimize aptamer-based strategies for widespread application in clinical settings.

Visualizing Neighborhood COVID-19 Levels, Trends, and Inequities in Wastewater: An Equity-Centered Approach and Comparison to CDC Methods.

Monitoring neighborhood-level SARS-CoV-2 wastewater concentrations can help guide public health interventions and provide early warning ahead of lagging COVID-19 clinical indicators. To date, however, U.S. Centers for Disease Control and Prevention's (CDC) National Wastewater Surveillance System (NWSS) has provided methodology solely for communicating national and state-level "wastewater viral activity levels." In October 2022, the Boston Public Health Commission (BPHC) began routinely sampling wastewater at 11 neighborhood sites to better understand COVID-19 epidemiology and inequities across neighborhoods, which vary widely in sociodemographic and socioeconomic characteristics. We developed equity-centered methods to routinely report interpretable and actionable descriptions of COVID-19 wastewater levels, trends, and neighborhood-level inequities. To produce these data visualizations, spanning October 2022 to December 2023, we followed four general steps: (1) smoothing raw values; (2) classifying current COVID-19 wastewater levels; (3) classifying current trends; and (4) reporting and visualizing results. COVID-19 wastewater levels corresponded well with lagged COVID-19 hospitalizations and deaths over time, with "Very High" wastewater levels coinciding with winter surges. When citywide COVID-19 levels were at the highest and lowest points, levels and trends tended to be consistent across sites. In contrast, when citywide levels were moderate, neighborhood levels and trends were more variable, revealing inequities across neighborhoods, emphasizing the importance of neighborhood-level results. Applying CDC/NWSS state-level methodology to neighborhood sites resulted in vastly different neighborhood-specific wastewater cut points for "High" or "Low," obscured inequities between neighborhoods, and systematically underestimated COVID-19 levels during surge periods in neighborhoods with the highest COVID-19 morbidity and mortality. Our methods offer an approach that other local jurisdictions can use for routinely monitoring, comparing, and communicating neighborhood-level wastewater levels, trends, and inequities. Applying CDC/NWSS methodology at the neighborhood-level can obscure and perpetuate COVID-19 inequities. We recommend jurisdictions adopt equity-focused approaches in neighborhood-level wastewater surveillance for valid community comparisons.

High SARS-CoV-2 seroincidence but low excess COVID mortality in Sierra Leone in 2020-2022.

While SARS-CoV-2 infection appears to have spread widely throughout Africa, documentation of associated mortality is limited. We implemented a representative serosurvey in one city of Sierra Leone in Western Africa, paired with nationally representative mortality and selected death registration data. Cumulative seroincidence using high quality SARS-CoV-2 serological assays was 69% by July 2021, rising to 84% by April 2022, mostly preceding SARS-CoV-2 vaccination. About half of infections showed evidence of neutralizing antibodies. However, excess death rates were low, and were concentrated at older ages. During the peak weeks of viral activity, excess mortality rates were 22% for individuals aged 30-69 years and 70% for those over 70. Based on electronic verbal autopsy with dual independent physician assignment of causes, excess deaths during viral peaks from respiratory infections were notable. Excess deaths differed little across specific causes that, a priori, are associated with COVID, and the pattern was consistent among adults with or without chronic disease risk factors. The overall 6% excess of deaths at ages ≥30 from 2020-2022 in Sierra Leone is markedly lower than reported from South Africa, India, and Latin America. Thus, while SARS-CoV-2 infection was widespread, our study highlights as yet unidentified mechanisms of heterogeneity in susceptibility to severe disease in parts of Africa.

Preparation and characterization of kelp polysaccharide and its research on anti-influenza a virus activity

The beneficial effects of kelp polysaccharide (KPS) have recently attracted attention. In this study, KPS was extracted from kelp using the enzyme hydrolysis combined with freeze-drying, namely, KPS-EF. The structural characterization showed that KPS-EF was a highly sulfated macromolecule with the Mw of 764.2 kDa and the sulfate content of 23.49 %. The antiviral activity of KPS-EF in vitro was verified, and the IC50 value of KPS against the PR8 virus was 0.58 mg/mL. Intranasal administration of KPS-EF significantly inhibited death and weight loss in IAV-infected mice and alleviated virus-induced pneumonia symptoms, meanwhile, KPS-EF (10 mg/kg/day) significantly decreased the production levels of chemokines (CXCL1, RANTES) and inflammatory cytokines (IL-6, TNF-α) in lungs (p < 0.05). KPS-EF could downregulate the activity of viral neuraminidase (NA) primarily in the late stage of viral adsorption with an IC50 value of 0.29 mg/mL. This study provides a theoretical basis for the using KPS as a supplement to NA inhibitors or anti-influenza drugs.

Antiviral Effects of Ozonated Water for Handwashing Against SARS-CoV-2 Omicron Variant Using the E1052-20 Test Method of the American Society of Testing Materials International

ABSTRACT Alcohol-based hand rubs are generally recommended for infection control of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Hand hygiene agents, including ozonated water (OW), have been used as an alternative because alcohol-based products may cause skin damage. A few reports are available on the virucidal activity of OW against SARS-CoV-2; therefore, this study examined the inhibitory effect of 0.4, 1.0, and 4.0 ppm OW on the Omicron variant infection to VeroE6 cells expressing transmembrane protease serine 2 by calculating the median tissue culture infectious dose (TCID50) using the E1052–20 test method of the American Society of Testing Materials International. Additionally, viral RNA copies were measured in culture supernatants of control or OW. Each OW concentration demonstrated ≥5.6 log10 TCID50 reduction, corresponding to ≥99.999% reduction of infectious virus, while the control phosphate-buffered saline showed no inactivation effect. More than 5 log10 copies/mL reduction of viral RNA was observed in the culture supernatant of each OW compared with the control. These findings suggest that exposure of SARS-CoV-2 to at least 0.4 ppm OW for 5 s is sufficient for viral inactivation and that OW can be used as an alternative hand hygiene agent to prevent SARS-CoV-2 infection.

Physical and Chemical Inactivators Evaluation for the Puumala Virus Vaccine Technology Development

Relevance. Hemorrhagic fever with renal syndrome (HFRS) is leading among natural focal human diseases in Russia, the causative agents of which - orthohantaviruses - belong to the order Bunyavirales, family Hantaviridae. More than 98% of HFRS cases in Russia are caused by the Puumala virus. It is a serious zoonosis for which there is still no specific treatment. The WHO has not approved a vaccine. The aim of this study was to investigate the effect of formaldehyde, β-propiolactone, hydrogen peroxide, ultraviolet rays, gamma irradiation and thermal inactivation on the immunogenic activity of inactivated vaccine preparations against HFRS Materials and methods. To achieve this aim, experimental vaccine preparations based on the PUU-TKD/VERO strain of Puumala virus were prepared and inactivated using the methods described above. The time intervals required for complete inactivation of the virus were determined, and the effects of the inactivators on viral RNA and immunogenic activity of the vaccine preparations were evaluated in BALB/c mouse and Syrian hamster models. Results. According to our results, vaccine preparations inactivated by different chemical and physical methods, which differ significantly in the mechanism of the mechanism of interaction with the virus, show no significant differences in immunogenic activity, except for thermal inactivation. Conclusion. A certain advantage of β-propiolactone is the short virus inactivation time, its complete degradation into non-toxic compounds within a few hours, and the reduction of total protein content after sterilization filtration, which is probably due to less aggregation of virus particles and cellular proteins

A Gaussia luciferase reporter assay for the evaluation of coronavirus Nsp5/3CLpro activity

Human coronaviruses (hCoVs) infect millions of people every year. Among these, MERS, SARS-CoV-1, and SARS-CoV-2 caused significant morbidity and mortality and their emergence highlights the risk of possible future coronavirus outbreaks. Therefore, broadly-active anti-coronavirus drugs are needed. Pharmacological inhibition of the hCoV protease Nsp5 (3CLpro) is clinically beneficial as shown by the wide and effective use of Paxlovid (nirmatrelvir, ritonavir). However, further treatment options are required due to the risk of drug resistance. To facilitate the assessment of coronavirus protease function and its pharmacological inhibition, we developed an assay allowing rapid and reliable quantification of Nsp5 activity under biosafety level 1 conditions. It is based on an ACE2-Gal4 transcription factor fusion protein separated by a Nsp5 recognition site. Cleavage by Nsp5 releases the Gal4 transcription factor, which then induces the expression of Gaussia luciferase. Our assay is compatible with Nsp5 proteases from all hCoVs and allows simultaneous measurement of inhibitory and cytotoxic effects of the tested compounds. Proof-of-concept measurements confirmed that nirmatrelvir, GC376 and lopinavir inhibit SARS-CoV-2 Nsp5 function. Furthermore, the assay accurately predicted the impact of Nsp5 mutations on catalytic activity and inhibitor sensitivity. Overall, the reporter assay is suitable for evaluating viral protease activity.

Increased parvovirus B19 seropositivity in healthy blood donors in India

A core component of every blood program is the supply of safe blood and blood products. The elevated risk of transmission through these products is due to parvovirus B19 (B19V) resistance to the virus inactivation procedures. Our study aimed to screen asymptomatic blood donors for B19V at a tertiary care hospital in Chennai, Tamil Nadu, between September 2020 and June 2021. Sera from 106 healthy blood donors who tested negative for Human immunodeficiency virus (HIV), Hepatitis B surface antigen (HBsAg), Hepatitis C virus (HCV), syphilis, and malaria were tested for anti-B19V IgM and IgG using a qualitative indirect enzyme-linked immunosorbent assay (ELISA). In the study population, 23.5% (n = 25) of donors tested IgM positive, 38.6% (n = 41) tested IgG positive, and 7.5% (n = 8) tested positive for both IgM and IgG. A proportion of 61.3% (n = 65) of the blood donors tested IgG negative, suggesting they had no past B19V infection. B19V DNA was not detected in any of the subjects. The high seroprevalence of IgM indicates that blood donors may have been recently exposed to B19V, potentially posing a risk to immunocompromised individuals and those with hematological stress. Further longitudinal studies with a larger sample size are recommended to better understand the risk of B19V transfusion transmission.

Evaluation of two household decontamination methods on protective mask materials and disinfection effects

Abstract In order to find affective disinfection methods for general public to reuse protective mask, which could address supply shortages in the period of epidemic, household ovens and household ultraviolet disinfection cabinets were used as decontamination tools, and the influence of decontamination process on the protective performance of masks including PFE and TIL, as well as virus (PV I and MHV) inactivation effect were completely evaluated. It was found that the dry heat and UVGI decontamination with household devices had a little impact on PFE or TIL of masks, which indicated that two process had little effect on mask material and face seal fit. The virus inactivation results showed that dry heat decontamination could effectively inactivate the virus on the masks, and UVGI decontamination could not completely inactivate the virus caused by the special shape of masks, which could be concluded that dry heat decontamination with household oven was a feasible method to reuse the mask, and UVGI decontamination was not recommended. This study had guiding significance for the decontamination and reuse of masks by the general public.

Virus inactivation using an electrically conducting virus filter in biopharmaceutical manufacturing process

Biopharmaceutical manufacturing processes using mammalian cells or plasma carry the risk of viral contamination. To mitigate these risks, it is essential to ensure viral clearance during the downstream process. Virus-retentive filters are used for size-based virus filtration, offering robust viral removal of more than 99.99%. However, virus breakthroughs have also been reported during virus filtration under certain conditions. In addition, these virus-retentive filters are disposable to ensure the safety of bioproducts, leading to significant costs and environmental concerns. In this study, innovative electrically conducting virus filters were fabricated using free-standing carbon veils (CV) and used to achieve additional virus inactivation after filtration. The viruses were captured in a CV-assisted virus filter, which was electrically heated using direct current to inactivate the viruses. This electrically conducting virus filter can inactivate viruses and can be reused up to five times. These results demonstrate that electrical conduction through electrical conducting damaged the phage capsid and eliminated the RNA genome, leading to bacteriophage inactivation. Moreover, it was confirmed that the electrically conducting virus filter could be reused up to five times without any changes to its physical or chemical structure. This study contributes to the reduction of process costs and environmental impacts by enabling the reuse of virus filters and enhancing the safety of the virus filtration process by preventing undesired virus breakthroughs.