ABSTRACT
Antibody-mediated immunity plays a key role in protection against SARS-CoV-2. We characterized B-cell-derived anti-SARS-CoV-2 RBD antibody repertoires from vaccinated and infected individuals and elucidate the mechanism of action of broadly neutralizing antibodies and dissect antibodies at the epitope level. The breadth and clonality of anti-RBD B cell response varies among individuals. The majority of neutralizing antibody clones lose or exhibit reduced activities against Beta, Delta, and Omicron variants. Nevertheless, a portion of anti-RBD antibody clones that develops after a primary series or booster dose of COVID-19 vaccination exhibit broad neutralization against emerging Omicron BA.2, BA.4, BA.5, BQ.1.1, XBB.1.5 and XBB.1.16 variants. These broadly neutralizing antibodies share genetic features including a conserved usage of the IGHV3-53 and 3-9 genes and recognize three clustered epitopes of the RBD, including epitopes that partially overlap the classically defined set identified early in the pandemic. The Fab-RBD crystal and Fab-Spike complex structures corroborate the epitope grouping of antibodies and reveal the detailed binding mode of broadly neutralizing antibodies. Structure-guided mutagenesis improves binding and neutralization potency of antibody with Omicron variants via a single amino-substitution. Together, these results provide an immunological basis for partial protection against severe COVID-19 by the ancestral strain-based vaccine and indicate guidance for next generation monoclonal antibody development and vaccine design.
Subject(s)
Antibodies, Neutralizing , Antibodies, Viral , COVID-19 Vaccines , COVID-19 , SARS-CoV-2 , Spike Glycoprotein, Coronavirus , Humans , SARS-CoV-2/immunology , Antibodies, Viral/immunology , COVID-19/immunology , COVID-19/prevention & control , COVID-19 Vaccines/immunology , Antibodies, Neutralizing/immunology , Spike Glycoprotein, Coronavirus/immunology , Immunization, Secondary , Epitopes/immunology , B-Lymphocytes/immunologyABSTRACT
In this study, a rapid diagnosis platform was developed for the detection of Escherichia coli O157:H7. An electrical double layer (EDL)-gated field-effect transistor-based biosensor (BioFET) as a point-of-care testing device is demonstrated with its high sensitivity, portability, high selectivity, quick response, and ease of use. The specially designed ssDNA probe was immobilized on the extended gate electrode to bind the target complementary DNA segment of E. coli, resulting in a sharp drain current change within minutes. The limit of detection for target DNA is validated to a concentration of 1 fM in buffer solution and serum. Meanwhile, the results of a Kelvin probe force microscope were shown to have reduced surface potential of the DNA immobilized sensors before and after the cDNA detection, which is consistent with the decreased drain current of the BioFET. A 1.2 kb E. coli duplex DNA synthesized in plasmid was sonicated and detected in serum samples with the sensor array. Gel electrophoresis was used to confirm the efficiency of sonication by elucidating the length of DNA. Those results show that the EDL-gated BioFET system is a promising platform for rapid identification of pathogens for future clinical needs.
Subject(s)
Biosensing Techniques , Escherichia coli Infections , Escherichia coli O157 , Humans , Biosensing Techniques/methods , DNA, Single-Stranded , Electrodes , Escherichia coli O157/genetics , DNA, Bacterial/geneticsABSTRACT
[This corrects the article DOI: 10.1371/journal.ppat.1009352.].
ABSTRACT
Serological and plasmablast responses and plasmablast-derived IgG monoclonal antibodies (MAbs) have been analysed in three COVID-19 patients with different clinical severities. Potent humoral responses were detected within 3 weeks of onset of illness in all patients and the serological titre was elicited soon after or concomitantly with peripheral plasmablast response. An average of 13.7% and 3.5% of plasmablast-derived MAbs were reactive with virus spike glycoprotein or nucleocapsid, respectively. A subset of anti-spike (10 of 32) antibodies cross-reacted with other betacoronaviruses tested and harboured extensive somatic mutations, indicative of an expansion of memory B cells upon SARS-CoV-2 infection. Fourteen of 32 anti-spike MAbs, including five anti-receptor-binding domain (RBD), three anti-non-RBD S1 and six anti-S2, neutralised wild-type SARS-CoV-2 in independent assays. Anti-RBD MAbs were further grouped into four cross-inhibiting clusters, of which six antibodies from three separate clusters blocked the binding of RBD to ACE2 and five were neutralising. All ACE2-blocking anti-RBD antibodies were isolated from two recovered patients with prolonged fever, which is compatible with substantial ACE2-blocking response in their sera. Finally, the identification of non-competing pairs of neutralising antibodies would offer potential templates for the development of prophylactic and therapeutic agents against SARS-CoV-2.
Subject(s)
Antibodies, Viral/immunology , COVID-19/immunology , SARS-CoV-2/immunology , Adult , Angiotensin-Converting Enzyme 2/antagonists & inhibitors , Angiotensin-Converting Enzyme 2/immunology , Antibodies, Monoclonal/immunology , Antibodies, Neutralizing/immunology , Antibodies, Viral/blood , Antibodies, Viral/genetics , Antibody-Producing Cells/immunology , Binding Sites , Epitopes , Humans , Immunoglobulin G/immunology , Nucleocapsid/immunology , Spike Glycoprotein, Coronavirus/immunologyABSTRACT
Serological responses (Seroresponse) and durability of hepatitis A virus (HAV) vaccination are reduced among human immunodeficiency virus (HIV)-positive patients. Incidence of and associated factors with early seroreversion (loss of seroresponse) among HIV-positive patients who have achieved seroresponses after two doses of HAV vaccination remain unclear. In this multicenter study, we followed HIV-positive adults who had mounted seroresponses after completing two doses of HAV vaccination during a recent outbreak of acute hepatitis A between 2015 and 2017, a 1:4 case-control study was conducted to identify factors associated with seroreversion. Case patients were those with seroreversion, and controls were those with similar follow-up durations who were able to maintain seroresponses. During the study period, 49 of the 1,256 patients (3.9%) seroreverted after a median follow-up of 611 days. In a case-control study, seroreversion was more likely to occur in patients with a higher weight (adjusted odds ratio [aOR], 1.703; 95% confidence interval [CI], 1.292-2.323, per 10-kg increment) and HIV viremia at the time of vaccination (aOR, 2.922; 95% CI, 1.067-7.924), whereas positive seroresponse at 6 months of HAV vaccination and higher CD4 lymphocyte counts at vaccination were inversely associated with early seroreversion with an aOR of 0.059 (95% CI, 0.020-0.154) and 0.837 (95% CI, 0.704-0.979, per 100-cell/mm3 increment), respectively, in multivariable analyses. Conclusion: During an outbreak setting, early seroreversion following two-dose HAV vaccination occurred in 3.9% of HIV-positive patients. Lower and delayed seroresponses to HAV vaccination, a higher weight, and HIV viremia and lower CD4 lymphocyte counts at the time of HAV vaccination were associated with early seroreversion. Regular monitoring of seroresponse and booster vaccination might be warranted, especially in HIV-positive adults with predictors of early seroreversion.
Subject(s)
HIV Seropositivity/blood , HIV Seropositivity/immunology , Hepatitis A Vaccines/administration & dosage , Hepatitis A Vaccines/immunology , Hepatitis A/prevention & control , Seroconversion , Adult , Case-Control Studies , Disease Outbreaks , Female , Hepatitis A/epidemiology , Humans , Male , Retrospective Studies , Time FactorsABSTRACT
INTRODUCTION: Ropeginterferon alfa-2b is a novel mono-pegylated proline-interferon. This clinical study aimed to evaluate its antiviral efficacy of ropeginterferon alfa-2b against SARS-CoV-2 infection. METHODS: This is a multicenter, randomized, open-label study. Adult patients with confirmed SARS-CoV-2 infection with initial cycle threshold (Ct) value < 30 and symptom onset within 4 days were enrolled. Eligible patients were randomized in a 2:1 ratio to receive a single 250-µg dose of ropeginterferon alfa-2b subcutaneously plus standard of care (SOC) or to receive SOC alone. The primary endpoint was the proportion of patients with a negative RT-PCR result for SARS-CoV-2 or discharged from the hospital before Day 8. Change in clinical status based on the World Health Organization (WHO) clinical progression scale and pulmonary infiltrations through chest radiograph were also evaluated. RESULTS: A total of 132 patients were enrolled and treated with study medication. Higher percentages of patients who achieved Ct ≥ 30 or were discharged from the hospital were observed on Day 8 and every other time point of assessment, i.e., Days 5, 11, 15, and 22, in the ropeginterferon alfa-2b group compared to the SOC alone group. However, the difference was statistically significant on Day 11 but not on Day 8. The primary endpoint was not met. The ropeginterferon alfa-2b group showed a higher improvement rate in lung infiltration on Day 5 (27.6% vs. 0.0%, p = 0.0087) and a higher improvement rate in WHO clinical progression scores on Day 8 (69.4% vs. 35.3%, p = 0.03) than those in the SOC group. No ropeginterferon alfa-2b-related serious adverse event was observed. CONCLUSION: Our data show that ropeginterferon alfa-2b with SOC shortened the duration of SARS-CoV-2 shedding compared with SOC alone. In addition, ropeginterferon alfa-2b as an additional therapy could be beneficial by improving lung infiltration.
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OBJECTIVES: Real-world experience with coformulated bictegravir, emtricitabine, and tenofovir alafenamide (BIC/FTC/TAF) is sparse as a switch regimen among people living with HIV (PLWH) having achieved viral suppression after previous virologic failures with the emergence of K65N/R. METHODS: In this retrospective study, PLWH aged ≥20 years who had previous virologic failures with emergent K65N/R were included for switching to BIC/FTC/TAF after having achieved plasma HIV RNA load (PVL) <200 copies/ml for ≥3 months. PLWH were excluded if integrase inhibitor resistance-associated mutations were detected. The primary end point was losing virologic control (PVL >50 copies/ml) at week 48 using a modified US Food and Drug Administration snapshot algorithm. RESULTS: A total of 72 PLWH with K65N/R who switched to BIC/FTC/TAF were identified. A total of 42 (59.7%) had concurrent M184V/I, and 9 (12.5%) had ≥1 thymidine analog mutations. The median duration of viral suppression was 4.7 years (interquartile range 2.3-5.8), and 97.2% (n = 70) had PVL <50 copies/ml before switching. After a median observation of 98.6 weeks (interquartile range 77.9-120.3), 94.4% (n = 68) continued BIC/FTC/TAF. At week 48, the rate of losing virologic control was 2.8% (2/72). M184V/I was not associated with viral rebound. CONCLUSION: Despite the emergence of K65N/R +/- M184V/I after virologic failures, BIC/FTC/TAF could be an option for simplification after viral suppression.
Subject(s)
Anti-HIV Agents , HIV Infections , Adult , Humans , Emtricitabine/therapeutic use , Tenofovir/therapeutic use , HIV Infections/drug therapy , Retrospective Studies , Drug Combinations , Adenine/therapeutic use , Heterocyclic Compounds, 4 or More Rings/therapeutic use , Mutation , Anti-HIV Agents/therapeutic use , Alanine/therapeutic use , Viral LoadABSTRACT
Although real-time reverse transcriptase polymerase chain reaction (real-time RT-PCR) remains as a golden standard for detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, it can not be easily expanded to large-scaled screening during outbreaks, and the positive results do not necessarily correlate with infectious status of the identified subjects. In this study, the performance of Vstrip® RV2 COVID-19 Antigen Rapid Test (RAT) and its correlation with virus infectivity was examined by virus culture using 163 sequential respiratory specimens collected from 26 SARS-CoV-2 infected patients. When the presence of cytopathic effects (CPE) in cell culture was used as a reference method for virus infectivity, the sensitivity, specificity and accuracy of Vstrip® RV2 COVID-19 Antigen Rapid Test was 96.43%, 89.63%, and 90.8%, respectively. The highest Ct value was 27.7 for RdRp gene and 25.79 for E gene within CPE-positive samples, and the highest Ct value was 31.9 for RdRp gene and 29.1 for E gene within RAT positive samples. When the Ct values of specimens were below 25, the CPE and RAT results had high degree of consistency. We concluded that the RAT could be a great alternative method for determining the infectious potential of individuals with high viral load.
ABSTRACT
BACKGROUND: Understanding the neutralizing antibody (NAb) titer against COVID-19 over time is important to provide information for vaccine implementation. The longitudinal NAb titer over one year after SARS-CoV-2 infection is still unclear. The purposes of this study are to evaluate the duration of the neutralizing NAb titers in COVID-19 convalescents and factors associated with the titer positive duration. METHODS: A cohort study followed COVID-19 individuals diagnosed between 2020 and 2021 May 15th from the COVID-19 database from the Taiwan Centers for Disease Control. We analyzed NAb titers from convalescent SARS-CoV-2 individuals. We used generalized estimating equations (GEE) and a Cox regression model to summarize the factors associated with NAb titers against COVID-19 decaying in the vaccine-free population. RESULTS: A total of 203 convalescent subjects with 297 analytic samples were followed for a period of up to 588 days. Our study suggests that convalescent COVID-19 in individuals after more than a year and four months pertains to only 25% of positive titers. The GEE model indicates that longer follow-up duration was associated with a significantly lower NAb titer. The Cox regression model indicated the disease severity with advanced condition was associated with maintaining NAb titers (adjusted hazard ratio: 2.01, 95% CI: 1.11-3.63) and that smoking was also associated with higher risk of negative NAb titers (adjusted hazard ratio: 0.55, 95% CI: 0.33-0.92). CONCLUSIONS: Neutralizing antibody titers diminished after more than a year. The antibody titer response against SARS-CoV-2 in naturally convalescent individuals provides a reference for vaccinations.
Subject(s)
COVID-19 , Humans , SARS-CoV-2 , Cohort Studies , Taiwan/epidemiology , Antibodies, Neutralizing , Antibodies, ViralABSTRACT
We report the safety and immunogenicity results in participants administrated with a booster dose of protein subunit vaccine MVC-COV1901 at 12 (Group A) or 24 (Group B) weeks after two doses of AZD1222 (ChAdOx1 nCoV-19). The administration of the MVC-COV1901 vaccine as a booster dose in both groups was generally safe. There were no serious adverse events related to the intervention as adverse events reported were "mild" or "moderate" in nature. In subjects fully vaccinated with two doses of AZD1222, waning antibody immunity was apparent within six months of the second dose of AZD1222. At one month after the MVC-COV1901 booster dose, those who were vaccinated within 12 weeks after the last AZD1222 dose (Group A) had anti-SARS-CoV-2 spike IgG antibody titers and neutralizing antibody titers which were 14- and 6.5-fold increased, respectively, when compared to the titer levels on the day of the booster dose. On the other hand, fold-increase a month post-booster in people who had a booster 24 weeks after the last AZD1222 dose (Group B) were 19.5 and 14.0 times for anti-SARS-CoV-2 spike IgG antibody titers and neutralizing antibody titers, respectively. Among those who were vaccinated within 12 weeks after the last AZD1222 dose, we also observed 5.2- and 5.6-fold increases in neutralizing titer levels against ancestral strain and Omicron variant pseudovirus after the booster dose, respectively. These results support the use of MVC-COV1901 as a heterologous booster for individuals vaccinated with AZD1222. Furthermore, regardless of the dosing schedule, the combination of AZD1222 primary series and MVC-COV1901 booster can be cost-effective and suitably applied to low- and middle-income countries (LMIC).
ABSTRACT
This report presents the case of a 59-year-old man with severe COVID-19 that gradually progressed to cytokine release syndrome and then acute respiratory distress syndrome; he was successfully treated via integration of therapeutic plasma exchange and traditional Chinese medicine. The patient initially presented with a sore throat, severe muscle aches, productive cough and fever. On the worsening of symptoms, remdesivir was administered. However, as the symptoms continued to worsen and a cytokine release syndrome was suspected, oxygen was provided through a high-flow nasal cannula (50 L/min) and therapeutic plasma exchange was performed to prevent worsening of the acute respiratory distress syndrome. On the same day, a course of traditional Chinese medicine was introduced in consultation with the infectious house staff. The patient's symptoms gradually improved; the levels of C-reactive protein and D-dimers reduced, and the patient was weaned to a simple oxygen mask and eventually to room air. This is the first reported case of the integration of these treatments. Together, they prevented the patient from requiring intubation, played a role in cytokine management, and also improved the clinical symptoms, including productive purulent sputum, cough, frequent stool passage and intermittent fever, with no adverse effects. As a result, the patient was discharged within two weeks of the integration of these treatments. Therefore, the integration of therapeutic plasma exchange and traditional Chinese medicine is an effective therapy for patients with severe COVID-19.
Subject(s)
COVID-19 , Respiratory Distress Syndrome , Male , Humans , Middle Aged , COVID-19/therapy , Cytokine Release Syndrome , Plasma Exchange , Medicine, Chinese Traditional , Cough/drug therapy , Respiratory Distress Syndrome/therapy , Oxygen/therapeutic useABSTRACT
Infection with hepatitis C virus (HCV) does not induce protective immunity, and re-exposure to HCV can reinfect the population engaging in high-risk behavior. An increasing incidence of acute hepatitis C infection in people living with HIV (PLWH) has been described in recent years. This retrospective cohort study was conducted in PLWH who completed HCV therapy between June 2009 and June 2020 at an HIV care hospital, to analyze their basic characteristics and risky behavior. Of 2419 patients, 639 were diagnosed with HCV infection and 516 completed the HCV therapy with a sustained virologic response. In total, 59 patients (11.4%) were reinfected with acute hepatitis C, and the median time to reinfection was 85.3 weeks (IQR: 57-150). The incidence of reinfection was 6.7 cases/100 person-years. The factors associated with reinfection were being male (AHR, 8.02; 95% CI 1.08-59.49), DAA (direct-acting antiviral) treatment (AHR, 2.23; 95% CI 1.04-4.79), liver cirrhosis (AHR, 3.94; 95% CI 1.09-14.22), heroin dependency (AHR: 7.41; 95% CI 3.37-14.3), and HIV viral loads <50 copies/mL at the follow-up (AHR: 0.47, 95% CI 0.24-0.93) in the subgroup of people who inject drugs (PWID). Amphetamine abuse (AHR: 20.17; 95% CI 2.36-172.52) was the dominant factor in the subgroup of men who have sex with men (MSM). Our study suggests that education and behavioral interventions are needed in this population to prevent reinfection.
Subject(s)
Antiviral Agents/therapeutic use , HIV Infections/epidemiology , Hepatitis C, Chronic/drug therapy , Reinfection/epidemiology , Adult , Drug Users , Female , HIV Infections/complications , Hepatitis C, Chronic/complications , Homosexuality, Male , Humans , Incidence , Kaplan-Meier Estimate , Male , Middle Aged , Proportional Hazards Models , Recurrence , Retrospective Studies , Risk Factors , Sustained Virologic Response , TaiwanABSTRACT
The outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has substantially affected human health globally. Spike-specific antibody response plays a major role in protection against SARS-CoV-2 infection. Here, we examined serological anti-spike antibody and memory B cell responses in adults with acute SARS-CoV-2 infection. Twenty-five adult patients were enrolled between January and September 2020, and 21 (84%) had a detectable spike-binding antibody response in serum on day 21 ± 8 (6 to 33) after the onset of illness. Among those with positive spike-binding antibody response, 19 (90%) had a positive hemagglutination titer and 15 (71%) had angiotensin-converting enzyme 2 (ACE2)-blocking serological activities. Follow-up serum samples collected 11 ± 1 (7 to 15) months after infection exhibited an average of 2.6 ± 1.0 (1.0 to 3.5)-fold reduction in the spike-binding antibody response. Moreover, convalescent and follow-up serum samples showed 83 ± 82 (15 to 306)- and 165 ± 167 (12 to 456)-fold reductions in the neutralization activity against the Omicron variant, respectively. Upon acute infection, spike-specific memory B cell responses were elicited, with an average frequency of 1.3% ± 1.2% of peripheral B cells on day 19 ± 7 (6 to 33) after the onset of illness. IgM memory B cells were predominantly induced. Patients with fever and pneumonia showed significantly stronger spike-binding, ACE2-blocking antibody, and memory B cell responses. In conclusion, spike-specific antibody response elicited upon acute SARS-CoV-2 infection may wane over time and be compromised by the emergence of viral variants. IMPORTANCE As spike protein-specific antibody responses play a major role in protection against SARS-CoV-2, we examined spike-binding and ACE2-blocking antibody responses in SARS-CoV-2 infection at different time points. We found robust responses following acute infection, which waned approximately 11 months after infection. Patients with fever and pneumonia showed significantly stronger spike-binding, ACE2-blocking antibody, and memory B cell responses. In particular, spike-specific antibody response in the convalescent and follow-up serum samples was substantially affected by emerging variants, especially Beta and Omicron variants. These results warrant continued surveillance of spike-specific antibody responses to natural infections and highlight the importance of maintaining functional anti-spike antibodies through immunization.
Subject(s)
COVID-19 , SARS-CoV-2 , Adult , Angiotensin-Converting Enzyme 2 , Antibodies, Neutralizing , Antibodies, Viral , Antibody Formation , Humans , Peptidyl-Dipeptidase A , Spike Glycoprotein, CoronavirusABSTRACT
Rapid development and deployment of vaccines is crucial to control the continuously evolving COVID-19 pandemic. The placebo-controlled phase 3 efficacy trial is still the standard for authorizing vaccines in the majority of the world. However, due to a lack of eligible participants in parts of the world, this has not always been feasible. Recently, the Taiwan Food and Drug Administration, following the consensus of the International Coalition of Medicines Regulatory Authorities (ICMRA), adopted the use of immunobridging studies as acceptable for authorizing COVID-19 vaccines in lieu of efficacy data. Here, we describe a study in which our candidate vaccine, MVC-COV1901, an adjuvanted protein subunit vaccine, has been granted emergency use authorization (EUA) in Taiwan based on a noninferiority immunobridging study. Immunogenicity results from the per protocol immunogenicity (PPI) subset (n = 903) from the MVC-COV1901 phase 2 trial were compared with results from 200 subjects who had received an adenovirus vector vaccine, AstraZeneca ChAdOx nCOV-19 (AZD1222), in a separate study. The lower bound of the 95% confidence interval (CI) of the geometric mean titer (GMT) ratio comparing MVC-COV1901 to AZD1222 was 3.4. The lower bound of the 95% CI of the sero-response rate was 95.5%. Both the GMT ratio and sero-response rate exceeded the criteria established by the Taiwan regulatory authority, leading to EUA approval of MVC-COV1901 in Taiwan.
ABSTRACT
Background: Administration of potent anti-receptor-binding domain (RBD) monoclonal antibodies has been shown to curtail viral shedding and reduce hospitalization in patients with SARS-CoV-2 infection. However, the structure-function analysis of potent human anti-RBD monoclonal antibodies and its links to the formulation of antibody cocktails remains largely elusive. Methods: Previously, we isolated a panel of neutralizing anti-RBD monoclonal antibodies from convalescent patients and showed their neutralization efficacy in vitro. Here, we elucidate the mechanism of action of antibodies and dissect antibodies at the epitope level, which leads to a formation of a potent antibody cocktail. Results: We found that representative antibodies which target non-overlapping epitopes are effective against wild type virus and recently emerging variants of concern, whilst being encoded by antibody genes with few somatic mutations. Neutralization is associated with the inhibition of binding of viral RBD to ACE2 and possibly of the subsequent fusion process. Structural analysis of representative antibodies, by cryo-electron microscopy and crystallography, reveals that they have some unique aspects that are of potential value while sharing some features in common with previously reported neutralizing monoclonal antibodies. For instance, one has a common VH 3-53 public variable region yet is unusually resilient to mutation at residue 501 of the RBD. We evaluate the in vivo efficacy of an antibody cocktail consisting of two potent non-competing anti-RBD antibodies in a Syrian hamster model. We demonstrate that the cocktail prevents weight loss, reduces lung viral load and attenuates pulmonary inflammation in hamsters in both prophylactic and therapeutic settings. Although neutralization of one of these antibodies is abrogated by the mutations of variant B.1.351, it is also possible to produce a bi-valent cocktail of antibodies both of which are resilient to variants B.1.1.7, B.1.351 and B.1.617.2. Conclusions: These findings support the up-to-date and rational design of an anti-RBD antibody cocktail as a therapeutic candidate against COVID-19.
Subject(s)
Antibodies, Monoclonal/chemistry , Antibodies, Monoclonal/pharmacology , COVID-19 Drug Treatment , SARS-CoV-2/metabolism , Angiotensin-Converting Enzyme 2/genetics , Angiotensin-Converting Enzyme 2/metabolism , Animals , Antibodies, Monoclonal/metabolism , Antibodies, Neutralizing/chemistry , Antibodies, Neutralizing/immunology , Antibodies, Neutralizing/pharmacology , Binding Sites , Binding, Competitive , COVID-19/virology , Cricetinae , Cryoelectron Microscopy , Crystallography, X-Ray , Dogs , Epitopes , Female , Humans , Madin Darby Canine Kidney Cells , Neutralization Tests , Protein Domains , SARS-CoV-2/genetics , SARS-CoV-2/immunology , SARS-CoV-2/pathogenicity , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/immunology , Spike Glycoprotein, Coronavirus/metabolismABSTRACT
To detect depression in people living with the human immunodeficiency virus (PLHIV), this preliminary study developed an artificial intelligence (AI) model aimed at discriminating the emotional valence of PLHIV. Sixteen PLHIV recruited from the Taoyuan General Hospital, Ministry of Health and Welfare, participated in this study from 2019 to 2020. A self-developed mobile application (app) was installed on sixteen participants' mobile phones and recorded their daily voice clips and emotional valence values. After data preprocessing of the collected voice clips was conducted, an open-source software, openSMILE, was applied to extract 384 voice features. These features were then tested with statistical methods to screen critical modeling features. Several decision-tree models were built based on various data combinations to test the effectiveness of feature selection methods. The developed model performed very well for individuals who reported an adequate amount of data with widely distributed valence values. The effectiveness of feature selection methods, limitations of collected data, and future research were discussed.
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To determine clinical performance of the single-target SARS-CoV-2 orf 1 ab reverse transcription-insulated isothermal PCR (RT-iiPCR) assay, the positive percentage agreement between this assay and a laboratory real-time RT-PCR assay was 96.8% (30 of 31; 95% confidence interval [CI], 90.5%-100%) and the negative percentage agreement was 97.1% (67 of 69; 95% CI, 93.1%-100%).
Subject(s)
COVID-19 Nucleic Acid Testing/methods , COVID-19/diagnosis , SARS-CoV-2/isolation & purification , Adult , Aged , Female , Humans , Male , Middle Aged , RNA, Viral/isolation & purification , Reverse Transcriptase Polymerase Chain Reaction , Sensitivity and Specificity , Young AdultABSTRACT
BACKGROUND/PURPOSE: Our study goals were to evaluate the diagnostic performance of four anti-SARS-CoV-2 antibodies tests and the differences in dynamic immune responses between COVID-19 patients with and without pneumonia. METHODS: We collected 184 serum samples from 70 consecutively qRT-PCR-confirmed COVID-19 patients at four participating hospitals from 23 January 2020 to 30 September 2020. COVID-19 pneumonia was defined as the presence of new pulmonary infiltration. Serum samples were grouped by the duration after symptom onset on a weekly basis for antibody testing and analysis. The four immunoassays: Beckman SARS-CoV-2 IgG/IgM (Beckman Test), Siemens (ADVIA Centaur®) SARS-CoV-2 Total (COV2T) (Siemens Test), SBC COVID-19 IgG ELISA (SBC Test) and EliA SARS-CoV-2-Sp1 IgG/IgM/IgA P2 Research (EliA Test) were used for detecting the SARS-CoV-2 specific antibodies. RESULTS: The sensitivity of all tests reached 100% after 42 days of symptom onset. Siemens Test, the only test detecting total anti-SARS-CoV-2 antibodies, had the best performance in the early diagnosis of COVID-19 infection (day 0-7: 77%; day 8-14: 95%) compared to the other 3 serological tests. All tests showed 100% specificity except SBC Test (98%). COVID-19 patients with pneumonia had significantly higher testing signal values than patients without pneumonia (all p values < 0.05, except EliA IgM Test). However, Siemens Test and SBC Test had highest probability in early prediction of the presence of COVID-19 pneumonia. CONCLUSION: Chronological analysis of immune response among COVID-19 patients with different serological tests provides important information in the early diagnosis of SARS-CoV-2 infection and prediction of the risk of pneumonia after infection.
Subject(s)
COVID-19 Testing/methods , COVID-19/diagnosis , Immunoassay/methods , Pneumonia/diagnosis , SARS-CoV-2/isolation & purification , Adult , Antibodies, Viral/blood , Antibody Formation , Early Diagnosis , Enzyme-Linked Immunosorbent Assay , False Positive Reactions , Female , Humans , Immunoglobulin A/blood , Immunoglobulin G/blood , Immunoglobulin M/blood , Male , Middle Aged , Retrospective Studies , Sensitivity and Specificity , Serologic Tests , TaiwanABSTRACT
Substantial COVID-19 research investment has been allocated to randomized clinical trials (RCTs) on hydroxychloroquine/chloroquine, which currently face recruitment challenges or early discontinuation. We aim to estimate the effects of hydroxychloroquine and chloroquine on survival in COVID-19 from all currently available RCT evidence, published and unpublished. We present a rapid meta-analysis of ongoing, completed, or discontinued RCTs on hydroxychloroquine or chloroquine treatment for any COVID-19 patients (protocol: https://osf.io/QESV4/ ). We systematically identified unpublished RCTs (ClinicalTrials.gov, WHO International Clinical Trials Registry Platform, Cochrane COVID-registry up to June 11, 2020), and published RCTs (PubMed, medRxiv and bioRxiv up to October 16, 2020). All-cause mortality has been extracted (publications/preprints) or requested from investigators and combined in random-effects meta-analyses, calculating odds ratios (ORs) with 95% confidence intervals (CIs), separately for hydroxychloroquine and chloroquine. Prespecified subgroup analyses include patient setting, diagnostic confirmation, control type, and publication status. Sixty-three trials were potentially eligible. We included 14 unpublished trials (1308 patients) and 14 publications/preprints (9011 patients). Results for hydroxychloroquine are dominated by RECOVERY and WHO SOLIDARITY, two highly pragmatic trials, which employed relatively high doses and included 4716 and 1853 patients, respectively (67% of the total sample size). The combined OR on all-cause mortality for hydroxychloroquine is 1.11 (95% CI: 1.02, 1.20; I² = 0%; 26 trials; 10,012 patients) and for chloroquine 1.77 (95%CI: 0.15, 21.13, I² = 0%; 4 trials; 307 patients). We identified no subgroup effects. We found that treatment with hydroxychloroquine is associated with increased mortality in COVID-19 patients, and there is no benefit of chloroquine. Findings have unclear generalizability to outpatients, children, pregnant women, and people with comorbidities.
Subject(s)
COVID-19 Drug Treatment , COVID-19/mortality , Chloroquine/adverse effects , Hydroxychloroquine/adverse effects , Pregnancy Complications, Infectious/mortality , Adult , COVID-19/complications , COVID-19/virology , Child , Chloroquine/administration & dosage , Combined Modality Therapy/adverse effects , Combined Modality Therapy/methods , Comorbidity , Female , Humans , Hydroxychloroquine/administration & dosage , International Cooperation , Odds Ratio , Patient Participation/statistics & numerical data , Pregnancy , Pregnancy Complications, Infectious/drug therapy , Pregnancy Complications, Infectious/virology , Randomized Controlled Trials as Topic/statistics & numerical data , SARS-CoV-2ABSTRACT
We fabricated InGaN/GaN nanorod light emitting diode (LED) arrays using nanosphere lithography for nanorod formation, PECVD (plasma enhanced chemical vapor deposition) grown SiO(2) layer for sidewall passivation, and chemical mechanical polishing for uniform nanorod contact. The nano-device demonstrates a reverse current 4.77nA at -5V, an ideality factor 7.35, and an optical output intensity 6807mW/cm(2) at the injection current density 32A/cm(2) (20mA). Moreover, the investigation of the droop effect for such a nanorod LED array reveals that junction heating is responsible for the sharp decrease at the low current.