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1.
Biosens Bioelectron ; 209: 114237, 2022 Aug 01.
Article in English | MEDLINE | ID: covidwho-1778012

ABSTRACT

Kinetics measurements of antigen-antibody binding interactions are critical to understanding the functional efficiency of SARS-CoV-2 antibodies. Previously reported chaotrope-based avidity assays that rely on artificial disruption of binding do not reflect the natural binding kinetics. This study developed a chaotrope- and label-free biolayer interferometry (BLI) assay for the real-time monitoring of receptor binding domain (RBD) binding kinetics with SARS-CoV-2 spike protein in convalescent COVID-19 patients. An improved conjugation biosensor probe coated with streptavidin-polysaccharide (SA-PS) led to a six-fold increase of signal intensities and two-fold reduction of non-specific binding (NSB) compared to streptavidin only probe. Furthermore, by utilizing a separate reference probe and biotin-human serum albumin (B-HSA) blocking process to subtracted NSB signal in serum, this BLI biosensor can measure a wide range of the dissociation rate constant (koff), which can be measured without knowledge of the specific antibody concentrations. The clinical utility of this improved BLI kinetics assay was demonstrated by analyzing the koff values in sera of 24 pediatric (≤18 years old) and 63 adult (>18 years old) COVID-19 convalescent patients. Lower koff values for SARS-CoV-2 serum antibodies binding to RBD were measured in samples from children. This rapid, easy to operate and chaotrope-free BLI assay is suitable for clinical use and can be readily adapted to characterize SARS-CoV-2 antibodies developed by COVID-19 patients and vaccines.


Subject(s)
Biosensing Techniques , COVID-19 , Adolescent , Adult , Antibodies, Neutralizing , Antibodies, Viral , Child , Humans , Immunologic Techniques , Interferometry , SARS-CoV-2 , Spike Glycoprotein, Coronavirus , Streptavidin
2.
EuropePMC; 2020.
Preprint in English | EuropePMC | ID: ppcovidwho-308924

ABSTRACT

Backgrounds: Outbreak of COVID-19 imposed great pressure on the professional work and psychological health of medical staff, especially in the early stage. This study aims to assess the coping ability and mental health status of medical workers and find influencing factors on them during the early stage of the COVID-19 outbreak. Methods: A cross-sectional study was conducted among medical staff in Henan from January 29th to February 4th with a total of 1739 participates. A self-made questionnaire was used to evaluate their coping ability and mental health status (Both total score 110). Chi-square analysis and multivariate logistic regression analysis was used to identify influencing factors on them. Results: The majority of the participants (96.8%) had coping ability scores (Median, 81;IQR, 75~87) above the passing line, most (65.0%) were in normal mental health (median, 58;IQR, 44~68). Analyses showed that older age, higher education level, and distrust in unofficial information were facilitating factors for better copying ability among medical workers. For mental health status, medical workers had 3 promoting factors: older age, distrust of unofficial information, and non-participation in epidemic prevention and control. On the other hand, poor physical health was a risk factor. ( P <0.05) Conclusions: In early stage of the epidemic, medical staff in Henan performed well in coping ability and mental health, but the government still needs to pay more attention to the coping capacity and mental health of medical workers who are younger, less educated, blind to unofficial information and in poor physical condition who may have worse coping ability and mental health status. And other studies are needed to determine the follow-up status.

3.
JCI Insight ; 6(20)2021 10 22.
Article in English | MEDLINE | ID: covidwho-1484165

ABSTRACT

Longitudinal studies are needed to evaluate the SARS-CoV-2 mRNA vaccine antibody response under real-world conditions. This longitudinal study investigated the quantity and quality of SARS-CoV-2 antibody response in 846 specimens from 350 patients, comparing BNT162b2-vaccinated individuals (19 previously diagnosed with COVID-19, termed RecoVax; and 49 never diagnosed, termed NaiveVax) with 122 hospitalized unvaccinated (HospNoVax) and 160 outpatient unvaccinated (OutPtNoVax) COVID-19 patients. NaiveVax experienced delay in generating SARS-CoV-2 total antibodies (TAb) and surrogate neutralizing antibodies (SNAb) after the first vaccine dose (D1) but rapid increase in antibody levels after the second dose (D2). However, these never reached RecoVax's robust levels. In fact, NaiveVax TAb and SNAb levels decreased 4 weeks after D2. For the most part, RecoVax TAb persisted, after reaching maximal levels 2 weeks after D2, but SNAb decreased significantly about 6 months after D1. Although NaiveVax avidity lagged behind that of RecoVax for most of the follow-up periods, NaiveVax did reach similar avidity by about 6 months after D1. These data suggest that 1 vaccine dose elicits maximal antibody response in RecoVax and may be sufficient. Also, despite decreasing levels in TAb and SNAb over time, long-term avidity may be a measure worth evaluating and possibly correlating to vaccine efficacy.


Subject(s)
Antibody Formation , COVID-19 Vaccines/immunology , COVID-19/immunology , COVID-19/prevention & control , Vaccines, Synthetic/immunology , Adult , Aged , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , Cohort Studies , Female , Humans , Longitudinal Studies , Male , Middle Aged , SARS-CoV-2 , Vaccination
4.
JCI Insight ; 6(20)2021 10 22.
Article in English | MEDLINE | ID: covidwho-1403153

ABSTRACT

Longitudinal studies are needed to evaluate the SARS-CoV-2 mRNA vaccine antibody response under real-world conditions. This longitudinal study investigated the quantity and quality of SARS-CoV-2 antibody response in 846 specimens from 350 patients, comparing BNT162b2-vaccinated individuals (19 previously diagnosed with COVID-19, termed RecoVax; and 49 never diagnosed, termed NaiveVax) with 122 hospitalized unvaccinated (HospNoVax) and 160 outpatient unvaccinated (OutPtNoVax) COVID-19 patients. NaiveVax experienced delay in generating SARS-CoV-2 total antibodies (TAb) and surrogate neutralizing antibodies (SNAb) after the first vaccine dose (D1) but rapid increase in antibody levels after the second dose (D2). However, these never reached RecoVax's robust levels. In fact, NaiveVax TAb and SNAb levels decreased 4 weeks after D2. For the most part, RecoVax TAb persisted, after reaching maximal levels 2 weeks after D2, but SNAb decreased significantly about 6 months after D1. Although NaiveVax avidity lagged behind that of RecoVax for most of the follow-up periods, NaiveVax did reach similar avidity by about 6 months after D1. These data suggest that 1 vaccine dose elicits maximal antibody response in RecoVax and may be sufficient. Also, despite decreasing levels in TAb and SNAb over time, long-term avidity may be a measure worth evaluating and possibly correlating to vaccine efficacy.


Subject(s)
Antibody Formation , COVID-19 Vaccines/immunology , COVID-19/immunology , COVID-19/prevention & control , Vaccines, Synthetic/immunology , Adult , Aged , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , Cohort Studies , Female , Humans , Longitudinal Studies , Male , Middle Aged , SARS-CoV-2 , Vaccination
5.
Engineering (Beijing) ; 2021 Jun 26.
Article in English | MEDLINE | ID: covidwho-1284079

ABSTRACT

Many microorganisms have mechanisms that protect cells against attack from viruses. The fermentation components of Streptomyces sp. 1647 exhibit potent anti-influenza A virus (IAV) activity. This strain was isolated from soil in southern China in the 1970s, but the chemical nature of its antiviral substance(s) has remained unknown until now. We used an integrated multi-omics strategy to identify the antiviral agents from this streptomycete. The antibiotics and Secondary Metabolite Analysis Shell (antiSMASH) analysis of its genome sequence revealed 38 biosynthetic gene clusters (BGCs) for secondary metabolites, and the target BGCs possibly responsible for the production of antiviral components were narrowed down to three BGCs by bioactivity-guided comparative transcriptomics analysis. Through bioinformatics analysis and genetic manipulation of the regulators and a biosynthetic gene, cluster 36 was identified as the BGC responsible for the biosynthesis of the antiviral compounds. Bioactivity-based molecular networking analysis of mass spectrometric data from different recombinant strains illustrated that the antiviral compounds were a class of structural analogues. Finally, 18 pseudo-tetrapeptides with an internal ureido linkage, omicsynins A1-A6, B1-B6, and C1-C6, were identified and/or isolated from fermentation broth. Among them, 11 compounds (omicsynins A1, A2, A6, B1-B3, B5, B6, C1, C2, and C6) are new compounds. Omicsynins B1-B4 exhibited potent antiviral activity against IAV with the 50% inhibitory concentration (IC50) of approximately 1 µmol∙L-1 and a selectivity index (SI) ranging from 100 to 300. Omicsynins B1-B4 also showed significant antiviral activity against human coronavirus HCoV-229E. By integrating multi-omics data, we discovered a number of novel antiviral pseudo-tetrapeptides produced by Streptomyces sp. 1647, indicating that the secondary metabolites of microorganisms are a valuable source of novel antivirals.

6.
Clin Chem ; 67(9): 1249-1258, 2021 09 01.
Article in English | MEDLINE | ID: covidwho-1207270

ABSTRACT

BACKGROUND: Low initial severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody titers dropping to undetectable levels within months after infection have raised concerns about long-term immunity. Both the antibody levels and the avidity of the antibody-antigen interaction should be examined to understand the quality of the antibody response. METHODS: A testing-on-a-probe "plus" panel (TOP-Plus) was developed to include a newly developed avidity assay built into the previously described SARS-CoV-2 TOP assays that measured total antibody (TAb), surrogate neutralizing antibody (SNAb), IgM, and IgG on a versatile biosensor platform. TAb and SNAb levels were compared with avidity in previously infected individuals at 1.3 and 6.2 months after infection in paired samples from 80 patients with coronavirus disease 2019 (COVID-19). Sera from individuals vaccinated for SARS-CoV-2 were also evaluated for antibody avidity. RESULTS: The newly designed avidity assay in this TOP panel correlated well with a reference Bio-Layer Interferometry avidity assay (r = 0.88). The imprecision of the TOP avidity assay was <10%. Although TAb and neutralization activity (by SNAb) decreased between 1.3 and 6.2 months after infection, the antibody avidity increased significantly (P < 0.0001). Antibody avidity in 10 SARS-CoV-2 vaccinated individuals (median: 28 days after vaccination) was comparable to the measured antibody avidity in infected individuals (median: 26 days after infection). CONCLUSIONS: This highly precise and versatile TOP-Plus panel with the ability to measure SARS-CoV-2 TAb, SNAb, IgG, and IgM antibody levels and avidity of individual sera on one sensor can become a valuable asset in monitoring not only patients infected with SARS-CoV-2 but also the status of individuals' COVID-19 vaccination response.


Subject(s)
Antibodies, Viral/blood , Antibody Affinity/physiology , Biosensing Techniques/methods , COVID-19/immunology , SARS-CoV-2/immunology , Adolescent , Adult , Aged , Antibodies, Neutralizing/blood , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , COVID-19/pathology , COVID-19/virology , COVID-19 Vaccines/administration & dosage , Female , Humans , Immunoglobulin G/blood , Immunoglobulin M/blood , Interferometry , Male , Middle Aged , SARS-CoV-2/isolation & purification , Time Factors , Young Adult
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