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1.
BMJ ; 369: m2195, 2020 06 10.
Article in English | MEDLINE | ID: covidwho-1430181

ABSTRACT

OBJECTIVE: To examine the protective effects of appropriate personal protective equipment for frontline healthcare professionals who provided care for patients with coronavirus disease 2019 (covid-19). DESIGN: Cross sectional study. SETTING: Four hospitals in Wuhan, China. PARTICIPANTS: 420 healthcare professionals (116 doctors and 304 nurses) who were deployed to Wuhan by two affiliated hospitals of Sun Yat-sen University and Nanfang Hospital of Southern Medical University for 6-8 weeks from 24 January to 7 April 2020. These study participants were provided with appropriate personal protective equipment to deliver healthcare to patients admitted to hospital with covid-19 and were involved in aerosol generating procedures. 77 healthcare professionals with no exposure history to covid-19 and 80 patients who had recovered from covid-19 were recruited to verify the accuracy of antibody testing. MAIN OUTCOME MEASURES: Covid-19 related symptoms (fever, cough, and dyspnoea) and evidence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, defined as a positive test for virus specific nucleic acids in nasopharyngeal swabs, or a positive test for IgM or IgG antibodies in the serum samples. RESULTS: The average age of study participants was 35.8 years and 68.1% (286/420) were women. These study participants worked 4-6 hour shifts for an average of 5.4 days a week; they worked an average of 16.2 hours each week in intensive care units. All 420 study participants had direct contact with patients with covid-19 and performed at least one aerosol generating procedure. During the deployment period in Wuhan, none of the study participants reported covid-19 related symptoms. When the participants returned home, they all tested negative for SARS-CoV-2 specific nucleic acids and IgM or IgG antibodies (95% confidence interval 0.0 to 0.7%). CONCLUSION: Before a safe and effective vaccine becomes available, healthcare professionals remain susceptible to covid-19. Despite being at high risk of exposure, study participants were appropriately protected and did not contract infection or develop protective immunity against SARS-CoV-2. Healthcare systems must give priority to the procurement and distribution of personal protective equipment, and provide adequate training to healthcare professionals in its use.


Subject(s)
Coronavirus Infections/prevention & control , Health Personnel , Infection Control/instrumentation , Pandemics/prevention & control , Personal Protective Equipment/supply & distribution , Pneumonia, Viral/prevention & control , Adult , Betacoronavirus , COVID-19 , China , Coronavirus Infections/diagnosis , Cross-Sectional Studies , Female , Humans , Infectious Disease Transmission, Patient-to-Professional/prevention & control , Intensive Care Units , Male , Middle Aged , Occupational Exposure/prevention & control , Pneumonia, Viral/diagnosis , SARS-CoV-2
2.
Pathog Immun ; 6(1): 116-134, 2021.
Article in English | MEDLINE | ID: covidwho-1389907

ABSTRACT

The approved Pfizer and Moderna mRNA vaccines are well known to induce serum antibody responses to the SARS-CoV-2 Spike (S)-protein. However, their abilities to elicit mucosal immune responses have not been reported. Saliva antibodies represent mucosal responses that may be relevant to how mRNA vaccines prevent oral and nasal SARS-CoV-2 transmission. Here, we describe the outcome of a cross-sectional study on a healthcare worker cohort (WELCOME-NYPH), in which we assessed whether IgM, IgG, and IgA antibodies to the S-protein and its receptor-binding domain (RBD) were present in serum and saliva samples. Anti-S-protein IgG was detected in 14/31 and 66/66 of saliva samples from uninfected participants after vaccine doses-1 and -2, respectively. IgA antibodies to the S-protein were present in 40/66 saliva samples after dose 2. Anti-S-protein IgG was present in every serum sample from recipients of 2 vaccine doses. Vaccine-induced antibodies against the RBD were also frequently present in saliva and sera. These findings may help our understanding of whether and how vaccines may impede SARS-CoV-2 transmission, including to oral cavity target cells.

3.
Front Microbiol ; 11: 2020, 2020.
Article in English | MEDLINE | ID: covidwho-1389203

ABSTRACT

Emerging highly pathogenic human coronaviruses (CoVs) represent a serious ongoing threat to the public health worldwide. The spike (S) proteins of CoVs are surface glycoproteins that facilitate viral entry into host cells via attachment to their respective cellular receptors. The S protein is believed to be a major immunogenic component of CoVs and a target for neutralizing antibodies (nAbs) and most candidate vaccines. Development of a safe and convenient assay is thus urgently needed to determine the prevalence of CoVs nAbs in the population, to study immune response in infected individuals, and to aid in vaccines and viral entry inhibitor evaluation. While live virus-based neutralization assays are used as gold standard serological methods to detect and measure nAbs, handling of highly pathogenic live CoVs requires strict bio-containment conditions in biosafety level-3 (BSL-3) laboratories. On the other hand, use of replication-incompetent pseudoviruses bearing CoVs S proteins could represent a safe and useful method to detect nAbs in serum samples under biosafety level-2 (BSL-2) conditions. Here, we describe a detailed protocol of a safe and convenient assay to generate vesicular stomatitis virus (VSV)-based pseudoviruses to evaluate and measure nAbs against highly pathogenic CoVs. The protocol covers methods to produce VSV pseudovirus bearing the S protein of the Middle East respiratory syndrome-CoV (MERS-CoV) and the severe acute respiratory syndrome-CoV-2 (SARS-CoV-2), pseudovirus titration, and pseudovirus neutralization assay. Such assay could be adapted by different laboratories and researchers working on highly pathogenic CoVs without the need to handle live viruses in the BSL-3 environment.

4.
J Clin Lab Anal ; 35(8): e23871, 2021 Aug.
Article in English | MEDLINE | ID: covidwho-1361198

ABSTRACT

BACKGROUND: To verify the differential expression of miR-30c and miR-142-3p between tuberculosis patients and healthy controls and to investigate the performance of microRNA (miRNA) and subsequently models for the diagnosis of tuberculosis (TB). METHODS: We followed up 460 subjects suspected of TB, and finally enrolled 132 patients, including 60 TB patients, 24 non-TB disease controls (TB-DCs), and 48 healthy controls (HCs). The differential expression of miR-30c and miR-142-3p in serum samples of the TB patients, TB-DCs, and HCs were identified by reverse transcription-quantitative real-time PCR. Diagnostic models were developed by analyzing the characteristics of miRNA and electronic health records (EHRs). These models evaluated by the area under the curves (AUC) and calibration curves were presented as nomograms. RESULTS: There were differential expression of miR-30c and miR-142-3p between TB patients and HCs (p < 0.05). Individual miRNA has a limited diagnostic value for TB. However, diagnostic performance has been both significantly improved when we integrated miR-142-3p and ordinary EHRs to develop two models for the diagnosis of tuberculosis. The AUC of the model for distinguishing tuberculosis patients from healthy controls has increased from 0.75 (95% CI: 0.66-0.84) to 0.96 (95% CI: 0.92-0.99) and the model for distinguishing tuberculosis patients from non-TB disease controls has increased from 0.67 (95% CI: 0.55-0.79) to 0.94 (95% CI: 0.89-0.99). CONCLUSIONS: Integrating serum miR-142-3p and EHRs is a good strategy for improving TB diagnosis.


Subject(s)
Electronic Health Records , MicroRNAs/blood , Nomograms , Tuberculosis/diagnosis , Adult , Aged , Case-Control Studies , Female , Humans , Male , Middle Aged , ROC Curve
5.
Clin Microbiol Infect ; 27(10): 1520.e7-1520.e10, 2021 Oct.
Article in English | MEDLINE | ID: covidwho-1297038

ABSTRACT

OBJECTIVES: Dexamethasone has become the standard of care for severe coronavirus disease 2019 (COVID-19), but its virological impact is poorly understood. The objectives of this work were to characterize the kinetics of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) concentration in the upper respiratory tract (URT) and the antibody response in patients with (D+) and without (D-) dexamethasone treatment. METHODS: Data and biosamples from hospitalized patients with severe COVID-19, enrolled between 4th March and 11th December 2020 in a prospective observational study, were analysed. SARS-CoV-2 virus concentration in serial URT samples was measured using RT-PCR. SARS-CoV-2-specific immunoglobulins A and G (IgA and IgG) were measured in serum samples using S1-ELISA. RESULTS: We compared 101 immunocompetent patients who received dexamethasone (according to the inclusion criteria and dosage determined in the RECOVERY trial) to 93 immunocompetent patients with comparable disease severity from the first months of the pandemic, who had not been treated with dexamethasone or other glucocorticoids. We found no inter-group differences in virus concentration kinetics, duration of presence of viral loads >106 viral copies/mL (D+ median 17 days (IQR 13-24), D- 19 days (IQR 13-29)), or time from symptom onset until seroconversion (IgA: D+ median 11.5 days (IQR 11-12), D- 14 days (IQR 11.5-15.75); IgG: D+ 13 days (IQR 12-14.5), D- 12 days (IQR 11-15)). CONCLUSION: Dexamethasone does not appear to lead to a change in virus clearance or a delay in antibody response in immunocompetent patients hospitalized with severe COVID-19.


Subject(s)
Antibodies, Viral/blood , COVID-19/drug therapy , Dexamethasone/therapeutic use , SARS-CoV-2/isolation & purification , Anti-Inflammatory Agents/therapeutic use , COVID-19/blood , COVID-19/immunology , COVID-19/virology , Hospitalization , Humans , Immunoglobulin A/blood , Immunoglobulin G/blood , Kinetics , Prospective Studies , RNA, Viral/analysis , Respiratory System/virology , SARS-CoV-2/genetics , SARS-CoV-2/immunology , Seroconversion , Viral Load
6.
J Clin Immunol ; 41(5): 914-922, 2021 07.
Article in English | MEDLINE | ID: covidwho-1293410

ABSTRACT

BACKGROUND: In a recent study, autoantibodies neutralizing type I interferons (IFNs) were present in at least 10% of cases of critical COVID-19 pneumonia. These autoantibodies neutralized most type I IFNs but rarely IFN-beta. OBJECTIVES: We aimed to define the prevalence of autoantibodies neutralizing type I IFN in a cohort of patients with severe COVID-19 pneumonia treated with IFN-beta-1b during hospitalization and to analyze their impact on various clinical variables and outcomes. METHODS: We analyzed stored serum/plasma samples and clinical data of COVID-19 patients treated subcutaneously with IFN-beta-1b from March to May 2020, at the Infanta Leonor University Hospital in Madrid, Spain. RESULTS: The cohort comprised 47 COVID-19 patients with severe pneumonia, 16 of whom (34%) had a critical progression requiring ICU admission. The median age was 71 years, with 28 men (58.6%). Type I IFN-alpha- and omega-neutralizing autoantibodies were found in 5 of 47 patients with severe pneumonia or critical disease (10.6%), while they were not found in any of the 118 asymptomatic controls (p = 0.0016). The autoantibodies did not neutralize IFN-beta. No demographic, comorbidity, or clinical differences were seen between individuals with or without autoantibodies. We found a significant correlation between the presence of neutralizing autoantibodies and higher C-reactive protein levels (p = 5.10e-03) and lower lymphocyte counts (p = 1.80e-02). No significant association with response to IFN-beta-1b therapy (p = 0.34) was found. Survival analysis suggested that neutralizing autoantibodies may increase the risk of death (4/5, 80% vs 12/42, 28.5%). CONCLUSION: Autoantibodies neutralizing type I IFN underlie severe/critical COVID-19 stages in at least 10% of cases, correlate with increased C-RP and lower lymphocyte counts, and confer a trend towards increased risk of death. Subcutaneous IFN-beta treatment of hospitalized patients did not seem to improve clinical outcome. Studies of earlier, ambulatory IFN-beta treatment are warranted.


Subject(s)
Antibodies, Neutralizing/blood , Autoantibodies/blood , COVID-19/immunology , Interferon Type I/immunology , SARS-CoV-2/immunology , Adult , Aged , Aged, 80 and over , C-Reactive Protein/analysis , Female , Hospitalization , Humans , Male , Middle Aged
7.
Indian J Med Res ; 153(5&6): 658-664, 2021 05.
Article in English | MEDLINE | ID: covidwho-1278593

ABSTRACT

Background & objectives: Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) continues to be a devastating pandemic. This study was aimed at performance assessment of SARS-CoV-2 IgM and IgG ELISAs, and investigation of their utility for patient diagnosis and sero-epidemiologic investigations. Methods: Serum/plasma samples from COVID-19 patients or asymptomatic contacts (n=180) and healthy donors (n=90) were tested in parallel using two commercial IgM ELISAs (Erbalisa and Inbios), and four IgG ELISAs (Kavach, Euroimmun, Erbalisa and Inbios) along with an indigenous ß-propiolactone inactivated virus-based ELISA (IRSHA-IgG-ELISA). Plaque reduction neutralization test (PRNT) was used as reference test. Results: Among 180 COVID-19 patients, 125 tested positive by PRNT. Inbios-IgM-ELISA showed sensitivity (Se)/specificity (Sp)/positive predictive value (PPV)/negative predictive value (NPV) of 93.6/97.8/98.4/94.4 per cent in relation to PRNT, and performed better than Erbalisa-IgM-ELISA (Se: 48%, Sp: 95.6%, PPV: 95.2%, NPV: 65.2%). During the first week of disease, only 47.4 per cent of the COVID-19 patients tested IgM positive by Inbios-IgM-ELISA, detection improving at two weeks and beyond (~86-100%). Among IgG tests, Inbios-IgG-ELISA ranked first in terms of sensitivity (83.2%), followed by IRSHA (64.8%), Euroimmun (64%), Erbalisa (57.6%) and Kavach (56%) tests. For all IgG tests, sensitivity improved during the third (73.9-95.7%) and fourth week (100%) of illness. The specificity (96.7-100%) and PPV (96.2-100%) of all IgG tests were high; NPV ranged between 71.9 and 87.1 per cent with Inbios-IgG-ELISA scoring highest. Interpretation & conclusions: Our results show that IgM detection by the current, most sensitive ELISAs cannot replace molecular diagnosis, but may aid as a supplement test. The available IgG tests are suitable for serosurveys for the assessment of previous virus exposure.


Subject(s)
COVID-19 , SARS-CoV-2 , Antibodies, Viral , Enzyme-Linked Immunosorbent Assay , Humans , Immunoglobulin G , Immunoglobulin M , Neutralization Tests , Sensitivity and Specificity
8.
Front Physiol ; 12: 653045, 2021.
Article in English | MEDLINE | ID: covidwho-1268280

ABSTRACT

Background: Tobacco smoking is known to be involved in the pathogenesis of several cardiopulmonary diseases. Additionally, smokers are highly susceptible to infectious agents due to weakened immunity. However, the progression of lung injury based on SARS-CoV-2-mediated COVID-19 pathogenesis amongst smokers and those with pre-existing pulmonary diseases is not known. We determined the systemic levels and activity of COVID-19 associated proteins, cytokine/chemokines, and lipid mediators (lipidomics) amongst COVID-19 patients with and without a history of smoking to understand the underlying susceptible factor in the pathogenesis of COVID-19. Methods: We obtained serum from healthy (CoV-), COVID-19 positive (CoV+), and COVID-19 recovered (CoV Rec) subjects with and without a history of smoking. We conducted a Luminex multiplex assay (cytokine levels), LC/MS (eicosanoids or oxylipin panel), and ACE2 enzymatic activity assays on the serum samples to determine the systemic changes in COVID-19 patients. Results: On comparing the levels of serum ACE2 amongst COVID-19 (positive and recovered) patients and healthy controls, we found a pronounced increase in serum ACE2 levels in patients with COVID-19 infection. Furthermore, ACE2 enzyme activity was significantly increased amongst COVID-19 patients with a smoking history. Also, we analyzed the levels of Angiotensin 1-7 (Ang1-7) peptide, the product of enzymatic action of ACE2, in the serum samples. We found significantly high levels of Ang1-7 in the serum of both CoV+ and CoV Rec patients. Our data further demonstrated a smoking-induced increase in serum furin and inflammatory cytokine [IFNγ(p = 0.0836), Eotaxin (p < 0.05), MCP-1 (p < 0.05), and IL-9 (p = 0.0991)] levels in COVID-19 patients as compared to non-smoking controls. Overall, our results show that smoking adversely affects the levels of systemic inflammatory markers and COVID-19 associated proteins, thus suggesting that COVID-19 infection may have severe outcomes amongst smokers.

9.
Clin Microbiol Infect ; 27(10): 1520.e1-1520.e5, 2021 Oct.
Article in English | MEDLINE | ID: covidwho-1260695

ABSTRACT

OBJECTIVES: To evaluate severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, hospitalization and fatality rates in residents of homeless shelters run by Samusocial of Paris. METHODS: We conducted a retrospective serological study between July and August 2020 on all residents and staff members of three homeless shelters run by Samusocial of Paris: two centres providing healthcare accommodation (HCA) and one a women's dormitory. We included all adults present in the shelters or who died of a proven SARS-CoV-2 infection during the first wave (March-May). SARS-CoV-2 antibodies were detected in serum samples using the SARS-CoV-2 IgG Architect (Abbott) test. Any participant with a positive PCR or serology was defined as a confirmed SARS-CoV-2 case. RESULTS: We included 100 residents and 83 staff members. The confirmed SARS-CoV-2 rate by PCR or serology was 72/100 (72.0%) for residents and 17/83 (20.5%) for staff members. Women accommodated in the dormitory had the highest infection rate (90.6%). The hospitalization rate in residents was 17/72 (23.6%) and the death rate 4/72 (5.6%). All hospitalizations and deaths occurred among HCA residents. Among the residents of HCA shelters, 34/68 (50%) presented at least two comorbidity factors associated with being at high risk for severe SARS-CoV-2 infection. CONCLUSION: The SARS-CoV-2 infection rate was high in residents of these homeless shelters (10.6% seroprevalence in the Île-de-France region during the first wave). Severe SARS-CoV-2 infection was highly associated with the prevalence of comorbidities. This population should be considered as a priority in vaccination campaigns and in access to individual housing units when at risk.


Subject(s)
COVID-19/epidemiology , Homeless Persons/statistics & numerical data , Adult , COVID-19/blood , COVID-19/mortality , Female , France/epidemiology , Hospitalization , Humans , Incidence , Male , Middle Aged , Prevalence , Retrospective Studies , Risk Factors , SARS-CoV-2/immunology , SARS-CoV-2/isolation & purification , Seroepidemiologic Studies
10.
Biosens Bioelectron ; 190: 113414, 2021 Oct 15.
Article in English | MEDLINE | ID: covidwho-1252505

ABSTRACT

Antibody detection methods for viral infections have received broad attention due to the COVID-19 pandemic. In addition, there remains an ever-increasing need to quantitatively evaluate the immune response to develop vaccines and treatments for COVID-19. Here, we report an analytical method for the rapid and quantitative detection of SARS-CoV-2 antibody in human serum by fluorescence polarization immunoassay (FPIA). A recombinant SARS-CoV-2 receptor binding domain (RBD) protein labeled with HiLyte Fluor 647 (F-RBD) was prepared and used for FPIA. When the anti-RBD antibody in human serum binds to F-RBD, the degree of polarization (P) increases by suppressing the rotational diffusion of F-RBD. The measurement procedure required only mixing a reagent containing F-RBD with serum sample and measuring the P value with a portable fluorescence polarization analyzer after 15 min incubation. We evaluated analytical performance of the developed FPIA system using 30 samples: 20 COVID-19 positive sera and 10 negative sera. The receiver operating characteristic curve drawn with the obtained results showed that this FPIA system had high accuracy for discriminating COVID-19 positive or negative serum (AUC = 0.965). The total measurement time was about 20 min, and the serum volume required for measurement was 0.25 µL. Therefore, we successfully developed the FPIA system that enables rapid and easy quantification of SARS-CoV-2 antibody. It is believed that our FPIA system will facilitate rapid on-site identification of infected persons and deepen understanding of the immune response to COVID-19.


Subject(s)
Biosensing Techniques , COVID-19 , Antibodies, Viral , Fluorescence Polarization Immunoassay , Humans , Pandemics , SARS-CoV-2
11.
Anal Bioanal Chem ; 413(18): 4645-4654, 2021 Jul.
Article in English | MEDLINE | ID: covidwho-1245612

ABSTRACT

Nucleic acid detection technology based on polymerase chain reaction (PCR) and antibody detection based on immunochromatography still have many problems such as false negatives for the diagnosis of coronavirus disease 2019 (COVID-19). Therefore, it is of great importance to develop new techniques to improve the diagnostic accuracy of COVID-19. We herein developed an ultrasensitive, rapid, and duplex digital enzyme-linked immunosorbent assay (dELISA) for simultaneous detection of spike (S-RBD) and nucleocapsid (N) proteins of SARS-CoV-2 based on a single molecule array. This assay effectively combines magnetic bead encoding technology and the ultrasensitive detection capability of a single molecule array. The detection strategies of S-RBD protein and N-protein exhibited wide response ranges of 0.34-1065 pg/mL and 0.183-338 pg/mL with detection limits of 20.6 fg/mL and 69.8 fg/mL, respectively. It is a highly specific method for the simultaneous detection of S-RBD protein and N-protein and has minimal interference from other blood proteins. Moreover, the spike assay showed a satisfactory and reproducible recovery rate for the detection of S-RBD protein and N-protein in serum samples. Overall, this work provides a highly sensitive method for the simultaneous detection of S-RBD protein and N-protein, which shows ultrasensitivity and high signal-to-noise ratio and contributes to improve the diagnosis accuracy of COVID-19.


Subject(s)
COVID-19/diagnosis , Coronavirus Nucleocapsid Proteins/isolation & purification , SARS-CoV-2/isolation & purification , Single Molecule Imaging/methods , Spike Glycoprotein, Coronavirus/isolation & purification , Antibodies, Viral/isolation & purification , Coronavirus Nucleocapsid Proteins/genetics , Enzyme-Linked Immunosorbent Assay/standards , Humans , Immunoassay/methods , Magnetics , Microspheres , Phosphoproteins/genetics , Phosphoproteins/isolation & purification , SARS-CoV-2/genetics , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/genetics
12.
Protein Expr Purif ; 186: 105908, 2021 10.
Article in English | MEDLINE | ID: covidwho-1243167

ABSTRACT

The current standard for the diagnosis of COVID-19 is the nucleic acid test of SARS-CoV-2 RNA, however, virus antibody detection has the advantages of convenient sample collection, high throughout, and low cost. When combining detection with nucleic acid detection, antibody detection can effectively compensate for nucleic acid detection. Virus infection always induce high antibody titer against SARS-CoV-2 nucleocapsid protein (N protein), which can be used to detect COVID-19 at both infected and convalescent patients. In this study we reported the expression and purification of N protein in E.coli from inclusion bodies by a combination of two cation exchange chromatography, and the yield of N protein was around 50 mg/L fermentation broth with more than 90% purity. A corresponding colloidal gold detection kit prepared with our purified N protein was used to verify the efficiency and accuracy our N protein in antibody detection method. Of the 58 COVID-19 PCR positive patients' inactivated serum samples, 40 samples were IgM positive (69.0%), and 42 samples were IgG positive (72.4%), and all 95 COVID-19 negative patients' inactivated serum samples were both IgM and IgG negative. Our results indicates that the refolded soluble N protein could be used for the preliminary detection of IgG and IgM antibodies against SARS-CoV- 2.


Subject(s)
Antibodies, Viral/blood , COVID-19 Serological Testing/methods , Coronavirus Nucleocapsid Proteins/genetics , Coronavirus Nucleocapsid Proteins/immunology , SARS-CoV-2/immunology , Coronavirus Nucleocapsid Proteins/biosynthesis , Coronavirus Nucleocapsid Proteins/isolation & purification , Escherichia coli/genetics , Humans , Immunoglobulin G/blood , Immunoglobulin M/blood , Inclusion Bodies , Phosphoproteins/biosynthesis , Phosphoproteins/genetics , Phosphoproteins/immunology , Phosphoproteins/isolation & purification , Recombinant Proteins/biosynthesis , Recombinant Proteins/immunology , Recombinant Proteins/isolation & purification , SARS-CoV-2/genetics , Sensitivity and Specificity
13.
Infection ; 49(5): 983-988, 2021 Oct.
Article in English | MEDLINE | ID: covidwho-1241719

ABSTRACT

PURPOSE: Seroprevalence surveys from different countries have reported SARS CoV-2 antibodies below 20% even in the most adversely affected areas and herd immunity cannot be predicted till more than half of the population gets the disease. The purpose of this survey was to estimate the magnitude of community-based spread of the infection, associated immunity, and the future prospects and proximity to a 'herd community'. METHODS: The study was undertaken as a cluster randomized, cross-sectional countrywide survey. This largest community-based seroprevalence data of SARS-CoV-2 were collected between 15th and 31st July, 2020 from seven randomly selected cities belonging to the three most populous provinces of Pakistan. The FDA approved kit of ROCHE was used for detection of SARS-CoV-2 antibodies. RESULTS: Serum samples of 15,390 participants were tested for SARS CoV-2 antibodies with an overall seroprevalence of 42.4%. The seroprevalence ranged from 31.1% to 48.1% in different cities with the highest in Punjab province (44.5%). In univariable analysis, the odds of seropositivity was higher in men compared to women (OR: 1.10, 95% CI: 1.01-1.19, P < 0.05). In multivariable analysis, the risk of being seropositive was lower (OR 0.72, 95% CI: 0.60-0.87, P < 0.01) in younger group (≤ 20 years) than in those aged above 60 years. CONCLUSION: The study concluded that despite a reasonable seroprevalence, the country is yet to reach the base minimum of estimations for herd immunity. The durability of immunity though debated at the moment, has shown an evidenced informed shift towards longer side.


Subject(s)
COVID-19 , SARS-CoV-2 , Aged , Antibodies, Viral , Cross-Sectional Studies , Female , Humans , Immunity, Herd , Male , Pakistan/epidemiology , Seroepidemiologic Studies
14.
Int J Hyg Environ Health ; 235: 113771, 2021 06.
Article in English | MEDLINE | ID: covidwho-1240386

ABSTRACT

PURPOSE: The objective of the ongoing study was to investigate how SARS-CoV-2 infection spread within two hospitals in North Rhine-Westphalia, Germany by testing the employees working in high-risk, intermediate-risk and low-risk-areas for the presence of SARS-CoV-2 IgG antibodies. Presented intermediate results evaluate the first infection period until the end of September 2020. METHODS: The study "COVID-19: Hotspot hospital?- Seroprevalence of SARS-CoV-2 antibodies in hospital employees in a secondary care hospital network in Germany " is a prospective, single centre observational cohort study conducted at the St. Vincenz Hospital Datteln with 316 beds. The presented data include one other hospital: St. Laurentius Stift Waltrop, Germany with 172 beds. RESULTS: Between June 2020 and September 2020 we analyzed serum samples of 907 employees which represents 62.1% of all employees. Thirteen employees (1.4%), respectively 13/696 healthcare workers (HCWs) (1.9%) had detectable SARS-CoV-2 IgG antibodies. Among them, 4 (30.8%) were aware of COVID-19 exposure, and 5 (38.5%) reported clinical symptoms. HCWs working in high-risk areas had a seroprevalence rate of 1.6% (1/64), HCWs working in intermediate-risk area 1.7% (11/632) and 0.5% employees (1/211) in low-risk areas with no contact to patients were seropositive. CONCLUSION: Even if we treated COVID-19 positive patients, we found no clear evidence that infection was transmitted to HCWs in contact to these patients. As knowledge about SARS-CoV-2 transmission evolves, the concept of infection prevention must be continuously reviewed and adapted as needed to keep hospitals a safe place.


Subject(s)
COVID-19/epidemiology , Health Personnel/statistics & numerical data , SARS-CoV-2/immunology , Secondary Care Centers/statistics & numerical data , Adolescent , Adult , Antibodies, Viral/blood , COVID-19/diagnosis , COVID-19/prevention & control , Disease Hotspot , Female , Germany/epidemiology , Humans , Immunoglobulin G/blood , Longitudinal Studies , Male , Prospective Studies , Risk Factors , SARS-CoV-2/isolation & purification , Seroepidemiologic Studies , Young Adult
15.
Schizophr Res ; 2021 May 17.
Article in English | MEDLINE | ID: covidwho-1230766

ABSTRACT

Epidemiologic studies have provided evidence that prenatal exposure to maternal infection is associated with an increased risk of developing schizophrenia in the offspring. Research over the past decade has added further to our understanding of the role of prenatal infection in schizophrenia risk. These investigations include several well-powered designs, and like some earlier studies, measured maternal antibodies to specific infectious agents in stored serum samples and large registers to identify clinically diagnosed infections during pregnancy. Convergent findings from antibody studies suggest that prenatal maternal infection with Toxoplasma gondii is associated with increased schizophrenia risk in the offspring, while associations with HSV-2 infection are likely attributable to confounding. Maternal influenza infection remains a viable candidate for schizophrenia, based on an early serological study, though there has been only one attempt to replicate this finding, with a differing methodology. A prior association between maternal serologically confirmed cytomegalovirus infections require further study. Clinically diagnosed maternal infection, particularly bacterial infection, also appears to be associated with increased risk of offspring schizophrenia, and heterogeneity in these findings is likely due to methodological differences between studies. Further clarification may be provided by future studies that address the timing, type, and clinical features of infections. Important insight may be gained by examining the long-term offspring outcomes in emerging epidemics such as Zika virus and COVID-19, and by investigating the interaction between exposure to prenatal infection and other risk or protective factors.

16.
Emerg Infect Dis ; 27(7): 1981-1984, 2021.
Article in English | MEDLINE | ID: covidwho-1225855

ABSTRACT

We detected severe acute respiratory syndrome coronavirus 2 in an otherwise healthy poodle living with 4 family members who had coronavirus disease. We observed antibodies in serum samples taken from the dog, indicating seroconversion. Full-length genome sequencing showed that the canine and human viruses were identical, suggesting human-to-animal transmission.


Subject(s)
COVID-19 , SARS-CoV-2 , Animals , Dogs , Humans , Italy/epidemiology
17.
STAR Protoc ; 2(2): 100573, 2021 06 18.
Article in English | MEDLINE | ID: covidwho-1225430

ABSTRACT

This protocol describes an indirect enzyme-linked immunosorbent assay for qualitative detection of IgG antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in Syrian hamster serum samples. We describe the preparation of inactivated virus antigens and the negative control antigen and the use of antigen-coated microtiter plates to detect SARS-CoV-2-specific antibodies from SARS-CoV-2-infected hamsters, including the criteria for differentiating positive versus negative reaction. The limited batch-to-batch variability of this assay has been verified with two batches of independently prepared antigens. For complete details on the use and execution of this protocol, please refer to Mohandas et al. (2021).


Subject(s)
Antibodies, Viral/blood , COVID-19/diagnosis , Coronavirus Nucleocapsid Proteins/immunology , Enzyme-Linked Immunosorbent Assay/methods , Immunoglobulin G/blood , Immunologic Tests/methods , SARS-CoV-2/immunology , Animals , Antibodies, Viral/immunology , COVID-19/blood , COVID-19/immunology , COVID-19/virology , Immunoglobulin G/immunology , Mesocricetus
18.
Immun Inflamm Dis ; 9(3): 905-917, 2021 09.
Article in English | MEDLINE | ID: covidwho-1224967

ABSTRACT

BACKGROUND: Hamburg is a city state of approximately 1.9 Mio inhabitants in Northern Germany. Currently, the COVID-19 epidemic that had largely subsided during last summer is resurging in Hamburg and in other parts of the world, underlining the need for additional tools to monitor SARS-CoV-2 antibody responses. AIM: We aimed to develop and validate a simple, low-cost assay for detecting antibodies against the native coronavirus 2 spike protein (CoV-2 S) that does not require recombinant protein or virus. METHOD: We transiently co-transfected HEK cells or CHO cells with expression vectors encoding CoV-2 S and nuclear GFP. Spike protein-specific antibodies in human serum samples bound to transfected cells were detected with fluorochrome conjugated secondary antibodies by flow cytometry orimmunofluorescence microscopy. We applied this assay to monitor antibody development in COVID-19 patients, household contacts, and hospital personnel during the ongoing epidemic in the city state of Hamburg. RESULTS: All recovered COVID-19 patients showed high levels of CoV-2 S-specific antibodies. With one exception, all household members that did not develop symptoms also did not develop detectable antibodies. Similarly, lab personnel that worked during the epidemic and followed social distancing guidelines remained antibody-negative. CONCLUSION: We conclude that high-titer CoV-2 S-specific antibodies are found in most recovered COVID-19 patients and in symptomatic contacts, but only rarely in asymptomatic contacts. The assay may help health care providers to monitor disease progression and antibody responses in vaccination trials, to identify health care personnel that likely are resistant to re-infection, and recovered individuals with high antibody titers that may be suitable asplasma and/or antibody donors.


Subject(s)
Antibodies, Viral/analysis , COVID-19 , Spike Glycoprotein, Coronavirus , Adult , Aged , Aged, 80 and over , Animals , COVID-19/immunology , Cricetinae , Cricetulus , Flow Cytometry , HEK293 Cells , Humans , Middle Aged , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/immunology
19.
Proc Natl Acad Sci U S A ; 118(18)2021 05 04.
Article in English | MEDLINE | ID: covidwho-1220061

ABSTRACT

Novel technologies are needed to facilitate large-scale detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) specific antibodies in human blood samples. Such technologies are essential to support seroprevalence studies and vaccine clinical trials, and to monitor quality and duration of immunity. We developed a microfluidic nanoimmunoassay (NIA) for the detection of anti-SARS-CoV-2 IgG antibodies in 1,024 samples per device. The method achieved a specificity of 100% and a sensitivity of 98% based on the analysis of 289 human serum samples. To eliminate the need for venipuncture, we developed low-cost, ultralow-volume whole blood sampling methods based on two commercial devices and repurposed a blood glucose test strip. The glucose test strip permits the collection, shipment, and analysis of 0.6 µL of whole blood easily obtainable from a simple finger prick. The NIA platform achieves high throughput, high sensitivity, and specificity based on the analysis of 289 human serum samples, and negligible reagent consumption. We furthermore demonstrate the possibility to combine NIA with decentralized and simple approaches to blood sample collection. We expect this technology to be applicable to current and future SARS-CoV-2 related serological studies and to protein biomarker analysis in general.


Subject(s)
Antibodies, Viral/blood , COVID-19 Serological Testing/methods , COVID-19/diagnosis , SARS-CoV-2/isolation & purification , COVID-19/blood , COVID-19 Serological Testing/economics , Dried Blood Spot Testing , High-Throughput Screening Assays/economics , Humans , Immunoassay/economics , Immunoglobulin G/blood , Microfluidic Analytical Techniques/economics , Reproducibility of Results , SARS-CoV-2/immunology , Sensitivity and Specificity , Specimen Handling
20.
Virol Sin ; 35(6): 744-751, 2020 Dec.
Article in English | MEDLINE | ID: covidwho-1217476

ABSTRACT

The coronavirus disease 2019 (COVID-19), caused by SARS-CoV-2, has spread around the world with high mortality. To diagnose promptly and accurately is the vital step to effectively control its pandemic. Dynamic characteristics of SARS-CoV-2-specific antibodies which are important for diagnosis of infection have not been fully demonstrated. In this retrospective, single-center, observational study, we enrolled the initial 131 confirmed cases of COVID-19 at Jin-Yin-Tan Hospital who had at least one-time antibody tested during their hospitalization. The dynamic changes of IgM and IgG antibodies to SARS-CoV-2 nucleocapsid protein in 226 serum samples were detected by ELISA. The sensitivities of IgM and IgG ELISA detection were analyzed. Result showed that the sensitivity of the IgG ELISA detection (92.5%) was significantly higher than that of the IgM (70.8%) (P < 0.001). The meantimes of seroconversion for IgM and IgG were 6 days and 3 days, respectively. The IgM and IgG antibody levels peaked at around 18 days and 23 days, and then IgM fell to below the baseline level at about day 36, whereas IgG maintained at a relatively high level. In conclusion, antibodies should be detected to aid in diagnosis of COVID-19 infection. IgG could be a sensitive indicator for retrospective diagnosis and contact tracing, while IgM could be an indicator of early infection.


Subject(s)
Antibodies, Viral/immunology , COVID-19/immunology , SARS-CoV-2/immunology , Adult , Aged , Aged, 80 and over , Antibodies, Viral/blood , COVID-19/blood , COVID-19/diagnosis , COVID-19/epidemiology , COVID-19 Serological Testing/methods , China/epidemiology , Enzyme-Linked Immunosorbent Assay , Female , Humans , Immunoglobulin G/blood , Immunoglobulin G/immunology , Immunoglobulin M/blood , Immunoglobulin M/immunology , Male , Middle Aged , Nucleocapsid Proteins/immunology , Pandemics , Retrospective Studies , Young Adult
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