Physical and mental health characteristics related to trust and intention toward COVID-19 vaccine: results from a community-based longitudinal study.

Objectives: To explore factors affecting attitudes toward COVID-19 vaccine, including sociodemographic characteristics and mental health status during the pandemic. Methods: Participants totaled 1,768, and were originally included in a community cohort study who responded to three online surveys related to COVID-19 (March 2020-March 2021). The K-means method was used to cluster trust and intention toward the COVID-19 vaccine. Baseline (2013-2018) sociodemographic characteristics, physical health status, and depressive symptoms were analyzed as exposure variables, and current mental health status was included in the analyses. Results: Most participants were classified into the moderate trust and high intention cluster (838, 47.4%); those with high trust and high intention accounted only for 16.86%. They tended to be older, had high-income level, and regular physical activity at baseline (p < 0.05); their sleep quality and psychological resilience were relatively high, compared to other groups. Conclusion: Our results suggest that more efforts are required to enhance the need and trust of COVID-19 vaccines.

Corticosteroids reduce pathologic interferon responses by downregulating STAT1 in patients with high-risk COVID-19.

We do not yet understand exactly how corticosteroids attenuate hyperinflammatory responses and alleviate high-risk coronavirus disease 2019 (COVID-19). We aimed to reveal the molecular mechanisms of hyperinflammation in COVID-19 and the anti-inflammatory effects of corticosteroids in patients with high-risk COVID-19. We performed single-cell RNA sequencing of peripheral blood mononuclear cells (PBMCs) from three independent COVID-19 cohorts: cohort 1 was used for comparative analysis of high-risk and low-risk COVID-19 (47 PBMC samples from 28 patients), cohort 2 for longitudinal analysis during COVID-19 (57 PBMC samples from 15 patients), and cohort 3 for investigating the effects of corticosteroid treatment in patients with high-risk COVID-19 (55 PBMC samples from 13 patients). PBMC samples from healthy donors (12 PBMC samples from 12 donors) were also included. Cohort 1 revealed a significant increase in the proportion of monocytes expressing the long noncoding RNAs NEAT1 and MALAT1 in high-risk patients. Cohort 2 showed that genes encoding inflammatory chemokines and their receptors were upregulated during aggravation, whereas genes related to angiogenesis were upregulated during improvement. Cohort 3 demonstrated downregulation of interferon-stimulated genes (ISGs), including STAT1, in monocytes after corticosteroid treatment. In particular, unphosphorylated STAT-dependent ISGs enriched in monocytes from lupus patients were selectively downregulated by corticosteroid treatment in patients with high-risk COVID-19. Corticosteroid treatment suppresses pathologic interferon responses in monocytes by downregulating STAT1 in patients with high-risk COVID-19. Our study provides insights into the mechanisms underlying COVID-19 aggravation and improvement and the effects of corticosteroid treatment.

The Rise of E-Wallets and Buy-Now-Pay-Later: Payment Competition, Credit Expansion, and Consumer Behavior (preprint)

The past decade has witnessed a phenomenal rise of digital wallets (e-wallets), and the COVID-19 pandemic further accelerated their adoption globally. The economic impact of e-wallets is unclear because they provide not only a conduit to external bank accounts but also internal payment options, including the ever-popular Buy-Now-Pay-Later (BNPL). We open the black box of e-wallets by examining transaction-level data matched with merchant and consumer information from a world-leading e-wallet provider in China, the userbase of which is representative of the population. We document that internal payment options, especially BNPL, dominate both online and on-site transactions. BNPL has greatly expanded credit access at the extensive margin through its adoption in two-sided payment markets. While BNPL crowds out other e-wallet payment options, it complements credit cards as seen in the behavior of users with both e-wallet credit and bank credit cards. Exploiting a randomized experiment, we also find that e-wallet credit through BNPL substantially boosts consumer spending. Nevertheless, users, especially those relying on e-wallets as their sole credit source, carefully moderate usage when incurring interest charges, likely as an attempt to improve their credit score. Our findings reveal that e-wallets go beyond being a sole payment channel to expand FinTech-based credit to underserved consumers. The insights apply to many economies transitioning from cash-heavy into cashless societies where digital payments and FinTech credit see the largest growth and market potential.

An antibody cocktail with broadened mutational resistance and effective protection against SARS-CoV-2.

Neutralizing antibodies have been proven to be highly effective in treating mild and moderate COVID-19 patients, but continuous emergence of SARS-CoV-2 variants poses significant challenges. Antibody cocktail treatments reduce the risk of escape mutants and resistance. In this study, a new cocktail composed of two highly potent neutralizing antibodies (HB27 and H89Y) was developed, whose binding epitope is different from those cocktails that received emergency use authorization. This cocktail showed more potent and balanced neutralizing activities (IC50 0.9-11.3 ng mL-1) against a broad spectrum of SARS-CoV-2 variants over individual HB27 or H89Y antibodies. Furthermore, the cocktail conferred more effective protection against the SARS-CoV-2 Beta variant in an aged murine model than monotherapy. It was shown to prevent SARS-CoV-2 mutational escape in vitro and effectively neutralize 61 types of pseudoviruses harbouring single amino acid mutation originated from variants and escape strains of Bamlanivimab, Casirivimab and Imdevimab with IC50 of 0.6-65 ng mL-1. Despite its breadth of variant neutralization, the HB27+H89Y combo and EUA cocktails lost their potencies against Omicron variant. Our results provide important insights that new antibody cocktails covering different epitopes are valuable tools to counter virus mutation and escape, highlighting the need to search for more conserved epitopes to combat Omicron.

Ratiometric fluorescent Si-FITC nanoprobe for immunoassay of SARS-CoV-2 nucleocapsid protein

Coronavirus disease 2019 (COVID-19) highlights the importance of rapid and reliable diagnostic assays for the management of virus transmission. Here, we developed a one-pot hydrothermal method to prepare Si-FITC nanoparticles (NPs) for the fluorescent immunoassay of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleocapsid protein (N protein). The synthesis of Si-FITC NPs did not need post-modification, which addressed the issue of quantum yield reduction during the coupling reaction. Si-FITC NPs showed two distinct peaks, Si fluorescence at λem = 385 nm and FITC fluorescence at λem = 490 nm. In the presence of KMnO4, Si fluorescence was decreased and FITC fluorescence was enhanced. Briefly, in the presence of N protein, catalase (CAT)-linked secondary antibody/reporter antibody/N protein/capture antibody immunocomplexes were formed on microplates. Subsequently, hydrogen peroxide (H2O2) and Si-FITC NPs/KMnO4 were injected into the microplate together. The decomposition of H2O2 by CAT resulted in remaining of KMnO4, which changed the fluorescence intensity ratio of Si-FITC NPs. The fluorescence intensity ratio correlated significantly with the N protein concentration ranging from 0.02 to 50.00 ng/mL, and the detection limit was 0.003 ng/mL, which was more sensitive than the commercial ELISA kit with a detection limit of 0.057 ng/mL. The N protein concentration can be accurately determined in human serum. Furthermore, the COVID-19 and non-COVID-19 patients were distinguishable by this method. Therefore, the ratiometric fluorescent immunoassay can be used for SARS-CoV-2 infection diagnosis with a high sensitivity and selectivity. Electronic Supplementary Material Supplementary material (characterization of Si-FITC NPs (FTIR, HRXPS);stability investigation of Si-FITC NPs (photostability, pH stability, anti-interference ability);stability investigation of free FITC (pH value, KMnO4);quenching mechanism of KMnO4 (UV-vis absorption spectra, fluorescence lifetime decay curves);reaction condition optimization of biotin-CAT with H2O2 (pH value, temperature, time);detection of N protein using commercial ELISA Kit;selectivity investigation of assays for SARS-CoV-2 N protein detection;determination results of SARS-CoV-2 N protein in human serum) is available in the online version of this article at 10.1007/s12274-022-5005-z.

The National Laboratory Response to the COVID-19 Pandemic in Taiwan.

From April 23 to November 2021, a wave of COVID-19 infections caused by a new Alpha variant swept across Taiwan, resulting in 14,458 positive cases and 830 deaths among over 3.8 million people tested. To cope with the sudden increase in sample volume, as of December 14, 2021, a network of 249 laboratories with a total diagnostic capacity of 158,492 real-time reverse transcription polymerase chain reaction tests per day was established in 22 administrative regions. As of April 2022, over 9.5 million specimens were tested. Fully automated high-throughput and point-of-care nucleic acid testing, and rapid antigen testing, were simultaneously implemented to expand the country's daily diagnostic capacity. Saliva testing and sample pooling were also introduced to increase screening efficiency in certain situations. Antibody testing and genomic sequencing were also adopted for more precise epidemic investigation. Other challenges encountered and overcome include a lack of resources and interfacing of laboratory information management systems for case reporting, limited specimen allocation and delivery, and limited staff for diagnostic processing.

Evaluation of conventional and point-of-care real-time RT-PCR tests for the detection of SARS-CoV-2 through a pooled testing strategy.

BACKGROUND: The rapid identification and isolation of individuals infected with SARS-CoV-2 are fundamental countermeasures for the efficient control of the COVID-19 pandemic, which has affected millions of people around the world. Real-time RT-PCR is one of the most commonly applied reference methods for virus detection, and the use of pooled testing has been proposed as an effective way to increase the throughput of routine diagnostic tests. However, the clinical applicability of different types of real-time RT-PCR tests in a given group size remains inconclusive due to inconsistent regional disease prevalence and test demands. METHODS: In this study, the performance of one dual-target conventional and two point-of-care real-time RT-PCR tests in a 5-specimen pooled testing strategy for the detection of SARS-COV-2 was evaluated. RESULTS: We demonstrated the proof of concept that all of these real-time RT-PCR tests could feasibly detect SARS-CoV-2 from nasopharyngeal and oropharyngeal specimens that contain viral RNA loads in the range of 3.48 × 105 to 3.42 × 102 copies/ml through pooled testing in a group size of 5 with overall positive percent agreement (pooling vs. individual testing) ranging from 100% to 93.75%. Furthermore, the two POC real-time RT-PCR tests exhibited comparable sensitivity to that of the dual-target conventional one when clinical specimens were tested individually. CONCLUSION: Our findings support the feasibility of using real-time RT-PCR tests developed as a variety of platforms in routine laboratory detection of suspected COVID-19 cases through a pooled testing strategy that is beneficial to increasing the daily diagnostic capacity.

COVID-19 and liver dysfunction: What nutritionists need to know.

The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus-2 has brought serious challenges for the medical field. Patients with COVID-19 usually have respiratory symptoms. However, liver dysfunction is not an uncommon presentation. Additionally, the degree of liver dysfunction is associated with the severity and prognosis of COVID-19. Prevention, diagnosis, and treatment of malnutrition should be routinely recommended in the management of patients with COVID-19, especially in those with liver dysfunction. Recently, a large number of studies have reported that nutrition therapy measures, including natural dietary supplements, vitamins, minerals and trace elements, and probiotics, might have potential hepatoprotective effects against COVID-19-related liver dysfunction via their antioxidant, antiviral, anti-inflammatory, and positive immunomodulatory effects. This review mainly focuses on the possible relationship between COVID-19 and liver dysfunction, nutritional and metabolic characteristics, nutritional status assessment, and nutrition therapy to provide a reference for the nutritionists while making evidence-based nutritional decisions during the COVID-19 pandemic.

SARS-CoV-2-specific CD4+ T cells are associated with long-term persistence of neutralizing antibodies.

Understanding the decay and maintenance of long-term SARS-CoV-2 neutralizing antibodies in infected or vaccinated people and how vaccines protect against other SARS-CoV-2 variants is critical for assessing public vaccination plans. Here, we measured different plasm antibody levels 2 and 12 months after disease onset, including anti-RBD, anti-N, total neutralizing antibodies, and two neutralizing-antibody clusters. We found that total neutralizing antibodies declined more slowly than total anti-RBD and anti-N IgG, and the two neutralizing-antibody clusters decayed even more slowly than total neutralizing antibodies. Interestingly, the level of neutralizing antibodies at 12 months after disease onset was significantly lower than that at 2 months but more broadly neutralized SARS-CoV-2 variants, including Alpha (B.1.1.7), Beta (B.1.351), Gamma (P.1), Delta (B.1.617.2), and Lambda (C.37). Significant immune escape by the Omicron variant (B.1.1.529) was also observed 2 months post-recovery. Furthermore, we revealed that a high percentage of virus-specific CD4+ T cells and cTfh1 were associated with a slower decline in humoral immunity, accompanied by higher levels of CXCR3 ligands such as CXCL9 and CXCL10, higher frequency of cTfh1, and lower levels of cTfh2 and cTfh17. Our data highlight the importance of coordinating T-cell and humoral immunity to achieve long-term protective immunity.

Potential role of vitamin D in patients with diabetes, dyslipidaemia, and COVID-19.

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus-2 has become a worldwide public health crisis. Studies have demonstrated that diabetes and dyslipidaemia are common comorbidities and could be high-risk factors for severe COVID-19. Vitamin D, a group of fat-soluble compounds responsible for intestinal absorption of calcium, magnesium, and phosphate, has been widely used as a dietary supplement for the prevention and treatment of numerous diseases, including infectious and non-infectious diseases, due to its high cost-effectiveness; safety; tolerability; and anti-thrombotic, anti-inflammatory, antiviral, and immunomodulatory properties. In this letter to the editor, we mainly discuss the potential role of vitamin D in patients with diabetes, dyslipidaemia, and COVID-19.

A Smartphone-Based Near-Vision Testing System: Design, Accuracy, and Reproducibility Compared With Standard Clinical Measures.

BACKGROUND AND OBJECTIVE: Ophthalmologic telemedicine has emerged during the COVID-19 pandemic. The objective of this study is to assess the accuracy and reproducibility of a smartphone-based home vision monitoring system (Sightbook) and to compare it with existing clinical standards. PATIENTS AND METHODS: Near Snellen visual acuity (VA) was measured with Sightbook and compared with conventional measurements for distance and near VA at an academic medical center ophthalmology clinic in 200 patients with a variety of different specified preexisting ocular conditions. Measurements of contrast sensitivity were also compared by using an existing commercially available chart system in 15 normal patients and 15 patients with age-related macular degeneration. RESULTS: Sightbook VA tests were reproducible (SD = ±0.054 logMAR), and correlation with standard VA methods was significant (R > 0.87 and P < .001). Sightbook contrast sensitivity measurements were reproducible (SD/mean ratio, 0.02 to 0.04), yielding results similar to those of standard tests (R2 > 0.87 and P < .001). CONCLUSIONS: Smartphone-based VA and contrast sensitivity are highly correlated with standard charts and may be useful in augmenting limited inoffice care. [Ophthalmic Surg Lasers Imaging Retina. 2022;53:79-84.].

Effectiveness of remote simulation-based learning for periodontal instrumentation: A non-inferiority study.

OBJECTIVES: While numerous virtual/remote simulation-based learning (SBL) modules were implemented due to the COVID-19 pandemic, limited data on their effectiveness are available. This study aimed to investigate the effectiveness of a remote SBL module for periodontal instrumentation compared to traditional onsite SBL modules. METHODS: Calibrated faculty members have instructed in all modules. Synchronous remote SBL activities using a secure videoconferencing application, which replaced onsite practices, were conducted in a small group setting in the remote SBL module for the class of 2023. After the class took the onsite second-year practical examination, a set of multiple and logistic regression analyses (N = 389) were conducted to test if the second-year practical examination scores and the passing rates were significantly different between the remote SBL (class of 2023) and onsite SBL I and II (class of 2019 and 2022) groups. RESULTS: Both mean practical examination score and passing rate from the remote SBL group (class of 2023) were significantly higher than those from the onsite SBL II group (class of 2022) when their first-year practical examination scores were not considered (p < 0.05). Once the first-year practical examination scores were considered, the remote SBL group was not significantly different from the onsite SBL I and II groups with respect to the mean second-year practical examination score and the passing rate. CONCLUSION: The proposed remote SBL module achieved the comparable student learning outcomes compared to the onsite SBL modules while it utilized less staff, time, and material expenditure.

Genomic analysis of early transmissibility assessment of the D614G mutant strain of SARS-CoV-2 in travelers returning to Taiwan from the United States of America.

BACKGROUND: There is a global pandemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Information on viral genomics is crucial for understanding global dispersion and for providing insight into viral pathogenicity and transmission. Here, we characterized the SARS-CoV-2 genomes isolated from five travelers who returned to Taiwan from the United States of America (USA) between March and April 2020. METHODS: Haplotype network analysis was performed using genome-wide single-nucleotide variations to trace potential infection routes. To determine the genetic variations and evolutionary trajectory of the isolates, the genomes of isolates were compared to those of global virus strains from GISAID. Pharyngeal specimens were confirmed to be SARS-CoV-2-positive by RT-PCR. Direct whole-genome sequencing was performed, and viral assemblies were subsequently uploaded to GISAID. Comparative genome sequence and single-nucleotide variation analyses were performed. RESULTS: The D614G mutation was identified in imported cases, which separated into two clusters related to viruses originally detected in the USA. Our findings highlight the risk of spreading SARS-CoV-2 variants through air travel and the need for continued genomic tracing for the epidemiological investigation and surveillance of SARS-CoV-2 using viral genomic data. CONCLUSIONS: Continuous genomic surveillance is warranted to trace virus circulation and evolution in different global settings during future outbreaks.

Significance of High-Containment Biological Laboratories Performing Work During the COVID-19 Pandemic: Biosafety Level-3 and -4 Labs.

High containment biological laboratories (HCBL) are required for work on Risk Group 3 and 4 agents across the spectrum of basic, applied, and translational research. These laboratories include biosafety level (BSL)-3, BSL-4, animal BSL (ABSL)-3, BSL-3-Ag (agriculture livestock), and ABSL-4 laboratories. While SARS-CoV-2 is classified as a Risk Group 3 biological agent, routine diagnostic can be handled at BSL-2. Scenarios involving virus culture, potential exposure to aerosols, divergent high transmissible variants, and zoonosis from laboratory animals require higher BSL-3 measures. Establishing HCBLs especially those at BSL-4 is costly and needs continual investments of resources and funding to sustain labor, equipment, infrastructure, certifications, and operational needs. There are now over 50 BSL-4 laboratories and numerous BSL-3 laboratories worldwide. Besides technical and funding challenges, there are biosecurity and dual-use risks, and local community issues to contend with in order to sustain operations. Here, we describe case histories for distinct HCBLs: representative national centers for diagnostic and reference, nonprofit organizations. Case histories describe capabilities and assess activities during COVID-19 and include capacities, gaps, successes, and summary of lessons learned for future practice.

Multicenter study evaluating novel multi-specimen pooling assay for the detection of SARS-CoV-2: High sensitivity and high throughput testing.

BACKGROUND/PURPOSE: Mass screening for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is important to prevent the spread of coronavirus disease 2019 (COVID-19). Pooling samples can increase the number of tests processed. LabTurbo AIO 48 is an automated platform that allows ribonucleic acid extraction and sample analysis on the same instrument. We created a novel pooling assay on this platform for SARS-CoV-2 detection and demonstrated that the pooling strategy increases testing capacity without affecting accuracy and sensitivity. METHODS: Comparative limit of detection (LoD) assessment was performed on the LabTurbo AIO 48 platform and the current standard detection system based on real-time reverse transcription polymerase chain reaction (rRT-PCR) using 55 clinically positive samples. An additional 330 primary clinical samples were assessed. RESULTS: Six samples pooled into one reaction tube were detected in approximately 2.5 h using the World Health Organization rRT-PCR protocol. LabTurbo AIO 48 also demonstrated a higher throughput than our reference rRT-PCR assay, with an LoD of 1000 copies/mL. The overall percentage agreement between the methods for the 330 samples was 100%. CONCLUSION: We created a novel multi-specimen pooling assay using LabTurbo AIO 48 for the robust detection of SARS-CoV-2, allowing high-throughput results; this assay will aid in better control and prevention of COVID-19. The diagnostic assay was cost-effective and time-efficient; thus, the pooling strategy is a practical and effective method for diagnosing large quantities of specimens without compromising precision.

Genomic evidence for divergent co-infections of SARS-CoV-2 lineages (preprint)

Recently, patients co-infected by two SARS-CoV-2 lineages have been sporadically reported. Concerns are raised because previous studies have demonstrated co-infection may contribute to the recombination of RNA viruses and cause severe clinic symptoms. In this study, we have estimated the compositional lineage(s), tendentiousness, and frequency of co-infection events in population from a large-scale genomic analysis for SARS-CoV-2 patients. SARS-CoV-2 lineage(s) infected in each sample have been recognized from the assignment of within-host site variations into lineage-defined feature variations by introducing a hypergeometric distribution method. Of all the 29,993 samples, 53 (~0.18%) co-infection events have been identified. Apart from 52 co-infections with two SARS-CoV-2 lineages, one sample with co-infections of three SARS-CoV-2 lineages was firstly identified. As expected, the co-infection events mainly happened in the regions where have co-existed more than two dominant SARS-CoV-2 lineages. However, co-infection of two sub-lineages in Delta lineage were detected as well. Our results provide a useful reference framework for the high throughput detecting of SARS-CoV-2 co-infection events in the Next Generation Sequencing (NGS) data. Although low in average rate, the co-infection events showed an increasing tendency with the increased diversity of SARS-CoV-2. And considering the large base of SARS-CoV-2 infections globally, co-infected patients would be a nonnegligible population. Thus, more clinical research is urgently needed on these patients.

Clinical Comparison of Three Sample-to-Answer Systems for Detecting SARS-CoV-2 in B.1.1.7 Lineage Emergence.

PURPOSE: Accurate molecular diagnostic assays for detecting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of COVID-19, are needed for epidemiology studies and to support infection-control measures. We evaluated the analytical sensitivity and clinical performance of three sample-to-answer molecular-diagnostics systems for detecting SARS-CoV-2 using 325 nasopharyngeal swab clinical samples from symptomatic patients. METHODS: The BioFire Respiratory Panel 2.1 (RP2.1), cobas Liat SARS-CoV-2 and Influenza A/B, and Cepheid Xpert Xpress SARS-CoV-2/Flu/RSV platforms, which have been granted emergency-use authorization by the US FDA, were tested and compared. RESULTS: The positive percent agreement, negative percent agreement, and overall percent agreement among the three point of care testing systems were 98-100%, including for the wild-type SARS-CoV-2 (non-B.1.1.7) and a variant of concern (B.1.1.7). Notably, the BioFire RP2.1 may fail to detect the SARS-CoV-2 S gene in the B.1.1.7 lineage because of the spike protein mutation. CONCLUSION: All three point of care testing platforms provided highly sensitive, robust, and almost accurate results for rapidly detecting SARS-CoV-2. These automated molecular diagnostic assays can increase the effectiveness of control and prevention measures for infectious diseases.

A cross-neutralizing antibody between HIV-1 and influenza virus.

Incessant antigenic evolution enables the persistence and spread of influenza virus in the human population. As the principal target of the immune response, the hemagglutinin (HA) surface antigen on influenza viruses continuously acquires and replaces N-linked glycosylation sites to shield immunogenic protein epitopes using host-derived glycans. Anti-glycan antibodies, such as 2G12, target the HIV-1 envelope protein (Env), which is even more extensively glycosylated and contains under-processed oligomannose-type clusters on its dense glycan shield. Here, we illustrate that 2G12 can also neutralize human seasonal influenza A H3N2 viruses that have evolved to present similar oligomannose-type clusters on their HAs from around 20 years after the 1968 pandemic. Using structural biology and mass spectrometric approaches, we find that two N-glycosylation sites close to the receptor binding site (RBS) on influenza hemagglutinin represent the oligomannose cluster recognized by 2G12. One of these glycan sites is highly conserved in all human H3N2 strains and the other emerged during virus evolution. These two N-glycosylation sites have also become crucial for fitness of recent H3N2 strains. These findings shed light on the evolution of the glycan shield on influenza virus and suggest 2G12-like antibodies can potentially act as broad neutralizers to target human enveloped viruses.