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1.
Trials ; 21(1): 499, 2020 06 08.
Article in English | MEDLINE | ID: covidwho-768581

ABSTRACT

OBJECTIVES: The aim of this study is to evaluate the efficacy and safety of human anti-SARS-CoV-2 convalescent plasma in hospitalized adults with severe SARS-CoV-2 infection. TRIAL DESIGN: This is a prospective, single-center, phase 2, randomized, controlled trial that is blinded to participants and clinical outcome assessor. PARTICIPANTS: Eligible participants include adults (≥ 18 years) with evidence of SARS-CoV-2 infection by PCR test of nasopharyngeal or oropharyngeal swab within 14 days of randomization, evidence of infiltrates on chest radiography, peripheral capillary oxygen saturation (SpO2) ≤ 94% on room air, and/or need for supplemental oxygen, non-invasive mechanical ventilation, or invasive mechanical ventilation, who are willing and able to provide written informed consent prior to performing study procedures or who have a legally authorized representative available to do so. Exclusion criteria include participation in another clinical trial of anti-viral agent(s)* for coronavirus disease-2019 (COVID-19), receipt of any anti-viral agent(s)* with possible activity against SARS-CoV-2 <24 hours prior to plasma infusion, mechanical ventilation (including extracorporeal membrane oxygenation [ECMO]) for ≥ 5 days, severe multi-organ failure, history of allergic reactions to transfused blood products per NHSN/CDC criteria, known IgA deficiency, and pregnancy. Included participants will be hospitalized at the time of randomization and plasma infusion. *Use of remdesivir as treatment for COVID-19 is permitted. The study will be undertaken at Columbia University Irving Medical Center in New York, USA. INTERVENTION AND COMPARATOR: The investigational treatment is anti-SARS-CoV-2 human convalescent plasma. To procure the investigational treatment, volunteers who recovered from COVID-19 will undergo testing to confirm the presence of anti-SARS-CoV-2 antibody to the spike trimer at a 1:400 dilution. Donors will also be screened for transfusion-transmitted infections (e.g. HIV, HBV, HCV, WNV, HTLV-I/II, T. cruzi, ZIKV). If donors have experienced COVID-19 symptoms within 28 days, they will be screened with a nasopharyngeal swab to confirm they are SARS-CoV-2 PCR-negative. Plasma will be collected using standard apheresis technology by the New York Blood Center. Study participants will be randomized in a 2:1 ratio to receive one unit (200 - 250 mL) of anti-SARS-CoV-2 plasma versus one unit (200 - 250 mL) of the earliest available control plasma. The control plasma cannot be tested for presence of anti-SARS-CoV-2 antibody prior to the transfusion, but will be tested for anti- SARS-CoV-2 antibody after the transfusion to allow for a retrospective per-protocol analysis. MAIN OUTCOMES: The primary endpoint is time to clinical improvement. This is defined as time from randomization to either discharge from the hospital or improvement by one point on the following seven-point ordinal scale, whichever occurs first. 1. Not hospitalized with resumption of normal activities 2. Not hospitalized, but unable to resume normal activities 3. Hospitalized, not requiring supplemental oxygen 4. Hospitalized, requiring supplemental oxygen 5. Hospitalized, requiring high-flow oxygen therapy or non-invasive mechanical ventilation 6. Hospitalized, requiring ECMO, invasive mechanical ventilation, or both 7. Death This scale, designed to assess clinical status over time, was based on that recommended by the World Health Organization for use in determining efficacy end-points in clinical trials in hospitalized patients with COVID-19. A recent clinical trial evaluating the efficacy and safety of lopinavir- ritonavir for patients hospitalized with severe COVID-19 used a similar ordinal scale, as have recent clinical trials of novel therapeutics for severe influenza, including a post-hoc analysis of a trial evaluating immune plasma. The primary safety endpoints are cumulative incidence of grade 3 and 4 adverse events and cumulative incidence of serious adverse events during the study period. RANDOMIZATION: Study participants will be randomized in a 2:1 ratio to receive anti-SARS-CoV-2 plasma versus control plasma using a web-based randomization platform. Treatment assignments will be generated using randomly permuted blocks of different sizes to minimize imbalance while also minimizing predictability. BLINDING (MASKING): The study participants and the clinicians who will evaluate post-treatment outcomes will be blinded to group assignment. The blood bank and the clinical research team will not be blinded to group assignment. NUMBERS TO BE RANDOMIZED (SAMPLE SIZE): We plan to enroll 129 participants, with 86 in the anti-SARS-CoV-2 arm, and 43 in the control arm. Among the participants, we expect ~70% or n = 72 will achieve clinical improvement. This will yield an 80% power for a one-sided Wald test at 0.15 level of significance under the proportional hazards model with a hazard ratio of 1.5. TRIAL STATUS: Protocol AAAS9924, Version 17APR2020, 4/17/2020 Start of recruitment: April 20, 2020 Recruitment is ongoing. TRIAL REGISTRATION: ClinicalTrials.gov: NCT04359810 Date of trial registration: April 24, 2020 Retrospectively registered FULL PROTOCOL: The full protocol is attached as an additional file, accessible from the Trials website (Additional file 1). In the interest of expediting dissemination of this material, the familiar formatting has been eliminated; this Letter serves as a summary of the key elements of the full protocol.


Subject(s)
Betacoronavirus/immunology , Coronavirus Infections/therapy , Pneumonia, Viral/therapy , Randomized Controlled Trials as Topic , Adult , Antibodies, Viral/blood , Antibodies, Viral/immunology , Clinical Trials, Phase II as Topic , Humans , Immunization, Passive/adverse effects , Immunization, Passive/methods , Pandemics , Prospective Studies
2.
Methods Mol Biol ; 2203: 55-65, 2020.
Article in English | MEDLINE | ID: covidwho-761346

ABSTRACT

Middle East respiratory syndrome coronavirus (MERS-CoV) is the etiological agent of MERS, a severe respiratory disease first reported in the Middle East in 2012. Serological assays are used to diagnose MERS-CoV infection and to screen for serum antibodies in seroepidemiological studies. The conventional enzyme-linked immunosorbent assay (ELISA) is the preferred tool for detecting serum antibodies specific for pathogens; however, the utility of conventional ELISA with respect to detection of MERS-CoV antibodies is limited due to the number of false-positives caused by cross-reactivity of serum antibodies with antigens that are conserved among coronaviruses. The competitive ELISA (cELISA) uses a pathogen-specific monoclonal antibody (MAb) that competes with serum antibodies for binding to an antigen; therefore, it is used widely for serological surveillance of many pathogens. In this chapter, I describe detection of serum antibodies using cELISA based on MAbs specific for MERS-CoV.


Subject(s)
Antibodies, Viral/blood , Coronavirus Infections/diagnosis , Enzyme-Linked Immunosorbent Assay/methods , Middle East Respiratory Syndrome Coronavirus/immunology , Animals , Antibodies, Monoclonal , Cross Reactions , Enzyme-Linked Immunosorbent Assay/instrumentation , Humans , Mice, Inbred BALB C
3.
J Coll Physicians Surg Pak ; 30(8): 801-804, 2020 Aug.
Article in English | MEDLINE | ID: covidwho-745629

ABSTRACT

OBJECTIVE: To determine the percentage of seroconverted real time reverse transcriptase polymerase chain reaction (RT-PCR) positive coronavirus disease (COVID-19) cases at different days post-symptom onset; and also find the agreement of chemiluminescence assay used for total antibody detection using RT-PCR as a reference method. STUDY DESIGN: Cross-sectional study. PLACE AND DURATION OF STUDY: Chughtai Institute of Pathology from April to May 2020. METHODOLOGY: Fifty pre-pandemic samples (healthy population) and 75 COVID-19 patients were included in the study. RT-PCR confirmed COVID-19 patients were divided into 3 equal groups (25 each), according to the days of symptom onset. The samples were analysed using electro-chemiluminescence as assay principle. Positive and negative agreement of COVID-19 antibodies was calculated using EP evaluator to find out the sensitivity of chemiluminescence assay for total antibody detection. The results were analysed using SPSS version 23.0. RESULTS: All the pre-pandemic samples tested were negative for antibodies with a negative agreement of 100%. Total agreement at day 7 post-symptom onset was 84%; whereas, it was 94% at day 14 and increased rapidly to 100% at day 21 post-symptom onset. At day 7 post-symptom onset, 68% of patients were seroconverted; and this percentage was 88% and 100% at day 14 and 21 post-symptom onset, respectively. CONCLUSION: Pre-pandemic samples were non-reactive for COVID-19 antibodies and seroconversion started within the first week post-virus exposure. There was 100% concordance between RT-PCR result and antibody positivity 21 days post-symptom onset. Key Words: COVID-19, SARS CoV-2, Seroconversion, Chemiluminescence.


Subject(s)
Antibodies, Viral/blood , Coronavirus Infections/diagnosis , Coronavirus/isolation & purification , Pneumonia, Viral/diagnosis , Adolescent , Adult , Betacoronavirus , Coronavirus/genetics , Coronavirus/immunology , Coronavirus Infections/epidemiology , Cross-Sectional Studies , Female , Humans , Luminescence , Male , Middle Aged , Pakistan/epidemiology , Pandemics , Pneumonia, Viral/epidemiology , Real-Time Polymerase Chain Reaction , Risk Factors , Seroconversion
4.
MMWR Morb Mortal Wkly Rep ; 69(35): 1221-1226, 2020 Sep 04.
Article in English | MEDLINE | ID: covidwho-745360

ABSTRACT

Health care personnel (HCP) caring for patients with coronavirus disease 2019 (COVID-19) might be at high risk for contracting SARS-CoV-2, the virus that causes COVID-19. Understanding the prevalence of and factors associated with SARS-CoV-2 infection among frontline HCP who care for COVID-19 patients are important for protecting both HCP and their patients. During April 3-June 19, 2020, serum specimens were collected from a convenience sample of frontline HCP who worked with COVID-19 patients at 13 geographically diverse academic medical centers in the United States, and specimens were tested for antibodies to SARS-CoV-2. Participants were asked about potential symptoms of COVID-19 experienced since February 1, 2020, previous testing for acute SARS-CoV-2 infection, and their use of personal protective equipment (PPE) in the past week. Among 3,248 participants, 194 (6.0%) had positive test results for SARS-CoV-2 antibodies. Seroprevalence by hospital ranged from 0.8% to 31.2% (median = 3.6%). Among the 194 seropositive participants, 56 (29%) reported no symptoms since February 1, 2020, 86 (44%) did not believe that they previously had COVID-19, and 133 (69%) did not report a previous COVID-19 diagnosis. Seroprevalence was lower among personnel who reported always wearing a face covering (defined in this study as a surgical mask, N95 respirator, or powered air purifying respirator [PAPR]) while caring for patients (5.6%), compared with that among those who did not (9.0%) (p = 0.012). Consistent with persons in the general population with SARS-CoV-2 infection, many frontline HCP with SARS-CoV-2 infection might be asymptomatic or minimally symptomatic during infection, and infection might be unrecognized. Enhanced screening, including frequent testing of frontline HCP, and universal use of face coverings in hospitals are two strategies that could reduce SARS-CoV-2 transmission.


Subject(s)
Antibodies, Viral/blood , Betacoronavirus/immunology , Coronavirus Infections/epidemiology , Personnel, Hospital/statistics & numerical data , Pneumonia, Viral/epidemiology , Academic Medical Centers , Adult , Asymptomatic Diseases , Coronavirus Infections/prevention & control , Coronavirus Infections/transmission , Cross Infection/prevention & control , Female , Humans , Infectious Disease Transmission, Professional-to-Patient/prevention & control , Male , Middle Aged , Pandemics/prevention & control , Personal Protective Equipment/statistics & numerical data , Pneumonia, Viral/prevention & control , Pneumonia, Viral/transmission , Seroepidemiologic Studies , United States/epidemiology
5.
In Vivo ; 34(5): 3039-3045, 2020.
Article in English | MEDLINE | ID: covidwho-740635

ABSTRACT

BACKGROUND: Antibody testing is necessary to identify immune individuals in the post-initial wave of the COVID-19 pandemic. PATIENTS AND METHODS: We prospectively evaluated the performance of a quantitative point-of-care test (POCT) for SARS-CoV-2 antibodies. The patient group (PG) comprised of hospitalized confirmed COVID-19 cases. Asymptomatic healthcare volunteers with negative rRT-PCR were included in the control group (CG). Measurement of IgM and IgG was obtained by dry fluorescence immunoassay. RESULTS: Twenty-six PG (65.9±15.4 years old, male 57.7%) and 18 CG (45.6±10.1 years old, male 33.3%) were included. By manufacturer's cut-off (≥0.04 mIU/ml), sensitivity and specificity were 73.08% and 88.89% for IgM and 88.46% and 33.33% for IgG, respectively. Estimated areas under the ROC curve were 0.907 and 0.848 for IgM and IgG, respectively. Results were improved using a cut-off of IgM ≥0.05 mIU/ml and IgG ≥0.10 mIU/ml. CONCLUSION: Using stringent cut-off values, SARS-CoV-2 antibody POCT detects immune people and can be used during socioeconomic normalization of communities.


Subject(s)
Antibodies, Viral/isolation & purification , Betacoronavirus/isolation & purification , Coronavirus Infections/diagnosis , Pandemics , Pneumonia, Viral/diagnosis , Aged , Antibodies, Viral/blood , Betacoronavirus/pathogenicity , Coronavirus Infections/epidemiology , Coronavirus Infections/virology , Greece/epidemiology , Humans , Immunoglobulin G/blood , Immunoglobulin G/isolation & purification , Male , Middle Aged , Pneumonia, Viral/epidemiology , Pneumonia, Viral/virology , Point-of-Care Systems , Sensitivity and Specificity
6.
Cien Saude Colet ; 25(9): 3573-3578, 2020 Sep.
Article in English | MEDLINE | ID: covidwho-740450

ABSTRACT

The first case of COVID-19 was reported in China in December 2019, and, as the virus has spread worldwide, the World Health Organization declared it a pandemic. Estimates on the number of COVID-19 cases do not reflect it real magnitude as testing is limited. Population based data on the proportion of the population with antibodies is relevant for planning public health policies. We aim to assess the prevalence of SARS-CoV-2 antibodies, presence of signs and symptoms of COVID-19, and adherence to isolation measures. A random sample comprising 133 sentinel cities from all states of the country will be selected. Three serological surveys, three weeks apart, will be conducted. The most populous municipality in each intermediate region of the country, defined by the Brazilian Institute of Geography and Statistics, was chosen as sentinel city. In each city, 25 census tracts will be selected, and 10 households will be systematically sampled in each tract, totaling 33,250 participants. In each household, one inhabitant will be randomly selected to be interviewed and tested for antibodies against SARS-CoV-2, using WONDFO SARS-CoV-2 Antibody Test. By evaluating a representative sample of Brazilian sentinel sites, this study will provide essential information for the design of health policies.


Subject(s)
Betacoronavirus/isolation & purification , Clinical Laboratory Techniques , Coronavirus Infections/epidemiology , Pneumonia, Viral/epidemiology , Public Health , Antibodies, Viral/blood , Betacoronavirus/immunology , Brazil/epidemiology , Coronavirus Infections/diagnosis , Health Policy , Humans , Pandemics , Pneumonia, Viral/diagnosis , Prevalence , Serologic Tests
7.
BMJ Open ; 10(8): e040448, 2020 08 30.
Article in English | MEDLINE | ID: covidwho-739117

ABSTRACT

OBJECTIVE: To assess the impact of describing an antibody-positive test result using the terms Immunity and Passport or Certificate, alone or in combination, on perceived risk of becoming infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and protective behaviours. DESIGN: 2×3 experimental design. SETTING: Online. PARTICIPANTS: 1204 adults from a UK research panel. INTERVENTION: Participants were randomised to receive one of six descriptions of an antibody test and results showing SARS-CoV-2 antibodies, differing in the terms describing the type of test (Immunity vs Antibody) and the test result (Passport vs Certificate vs Test). MAIN OUTCOME MEASURES: Primary outcome: proportion of participants perceiving no risk of infection with SARS-CoV-2 given an antibody-positive test result. Other outcomes include: intended changes to frequency of hand washing and physical distancing. RESULTS: When using the term Immunity (vs Antibody), 19.1% of participants (95% CI 16.1% to 22.5%) (vs 9.8% (95% CI 7.5% to 12.4%)) perceived no risk of catching coronavirus given an antibody-positive test result (adjusted OR (AOR): 2.91 (95% CI 1.52 to 5.55)). Using the terms Passport or Certificate-as opposed to Test-had no significant effect (AOR: 1.24 (95% CI 0.62 to 2.48) and AOR: 0.96 (95% CI 0.47 to 1.99) respectively). There was no significant interaction between the effects of the test and result terminology. Across groups, perceiving no risk of infection was associated with an intention to wash hands less frequently (AOR: 2.32 (95% CI 1.25 to 4.28)); there was no significant association with intended avoidance of physical contact (AOR: 1.37 (95% CI 0.93 to 2.03)). CONCLUSIONS: Using the term Immunity (vs Antibody) to describe antibody tests for SARS-CoV-2 increases the proportion of people believing that an antibody-positive result means they have no risk of catching coronavirus in the future, a perception that may be associated with less frequent hand washing. TRIAL REGISTRATION NUMBER: Open Science Framework: https://osf.io/tjwz8/files/.


Subject(s)
Antibodies, Viral , Communication , Coronavirus Infections , Health Behavior , Health Knowledge, Attitudes, Practice , Immunity , Pandemics , Pneumonia, Viral , Adult , Antibodies, Viral/blood , Betacoronavirus , Certification , Coronavirus Infections/blood , Coronavirus Infections/prevention & control , Coronavirus Infections/virology , Disclosure , Female , Humans , Internet , Male , Odds Ratio , Pandemics/prevention & control , Pneumonia, Viral/blood , Pneumonia, Viral/prevention & control , Pneumonia, Viral/virology , Risk Assessment , United Kingdom
8.
Anal Chem ; 92(16): 11305-11309, 2020 08 18.
Article in English | MEDLINE | ID: covidwho-733550

ABSTRACT

The SARS-CoV-2 pandemic has created an unprecedented need for rapid diagnostic testing to enable the efficient treatment and mitigation of COVID-19. The primary diagnostic tool currently employed is reverse transcription polymerase chain reaction (RT-PCR), which can have good sensitivity and excellent specificity. Unfortunately, implementation costs and logistical problems with reagents during the global SARS-CoV-2 pandemic have hindered its universal on demand adoption. Lateral flow assays (LFAs) represent a class of diagnostic that, if sufficiently clinically sensitive, may fill many of the gaps in the current RT-PCR testing regime, especially in low- and middle-income countries (LMICs). To date, many serology LFAs have been developed, though none meet the performance requirements necessary for diagnostic use cases, primarily due to the relatively long delay between infection and seroconversion. However, on the basis of previously reported results from SARS-CoV-1, antigen-based SARS-CoV-2 assays may have significantly better clinical sensitivity than serology assays. To date, only a very small number of antigen-detecting LFAs have been developed. Development of a half-strip LFA is a useful first step in the development of any LFA format. In this work, we present a half-strip LFA using commercially available antibodies for the detection of SARS-CoV-2. We have tested this LFA in buffer and measured an LOD of 0.65 ng/mL (95% CI of 0.53 to 0.77 ng/mL) ng/mL with recombinant antigen using an optical reader with sensitivity equivalent to a visual read. Further development, including evaluating the appropriate sample matrix, will be required for this assay approach to be made useful in a point of care setting, though this half-strip LFA may serve as a useful starting point for others developing similar tests.


Subject(s)
Betacoronavirus/metabolism , Coronavirus Infections/diagnosis , Immunoassay/methods , Nucleocapsid/immunology , Pneumonia, Viral/diagnosis , Point-of-Care Systems , Antibodies, Viral/blood , Antigens/immunology , Betacoronavirus/isolation & purification , Coronavirus Infections/virology , Humans , Limit of Detection , Pandemics , Pneumonia, Viral/virology
9.
Front Cell Infect Microbiol ; 10: 445, 2020.
Article in English | MEDLINE | ID: covidwho-732914

ABSTRACT

A new type of coronavirus-induced pneumonia eventually termed "coronavirus disease 2019" (COVID-19) was diagnosed in patients in Wuhan (Hubei Province, China) in December 2019, and soon spread worldwide. To improve the detection rate of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), we analyzed the results of viral nucleic acid and serum-specific antibody tests on clinical samples from 20 patients with SARS-CoV-2 infection diagnosed at the First Affiliated Hospital of Guangzhou Medical University in China. By comparing various sample types collected from COVID-19 patients, we revealed multiple pathways for SARS-CoV-2 shedding, and a prolonged detectable period for viral nucleic acid test in sputum specimens, demonstrating that the timeline of the viral shedding is of great value in determining the time of release from quarantine or discharge from hospital. We also recommend for the application of serological test to assist in confirming SARS-CoV-2 infection judged by viral nucleic acid test, especially when COVID-19-related symptoms have appeared and the viral nucleic acid test was negative. Our findings are critical for the diagnosis of SARS-CoV-2 infection and for determining deadline of restriction measures to prevent transmission caused by convalescent patients with COVID-19.


Subject(s)
Betacoronavirus/isolation & purification , Clinical Laboratory Techniques , Coronavirus Infections/diagnosis , Feces/virology , Immunoglobulin G/blood , Immunoglobulin M/blood , Pneumonia, Viral/diagnosis , Sputum/virology , Antibodies, Viral/blood , Betacoronavirus/genetics , Betacoronavirus/physiology , Female , Humans , Male , Middle Aged , Pandemics , RNA, Viral/analysis , Reverse Transcriptase Polymerase Chain Reaction , Sensitivity and Specificity , Serologic Tests , Virus Shedding
10.
J Korean Med Sci ; 35(33): e311, 2020 Aug 24.
Article in English | MEDLINE | ID: covidwho-729635

ABSTRACT

Serosurveillance studies reveal the actual disease burden and herd immunity level in the population. In Seoul, Korea, a cross-sectional investigation showed 0.07% anti-severe acute respiratory syndrome coronavirus-2 antibody seropositivity among 1,500 outpatients of the university hospitals. Low seroprevalence reflects well-implemented social distancing. Serosurveillance should be repeated as the pandemic progresses.


Subject(s)
Antibodies, Viral/blood , Betacoronavirus/immunology , Adolescent , Adult , Aged , Aged, 80 and over , Child , Child, Preschool , Coronavirus Infections/epidemiology , Coronavirus Infections/immunology , Cross-Sectional Studies , Female , Hospitals, University , Humans , Infant , Infant, Newborn , Male , Middle Aged , Outpatients , Pandemics , Pneumonia, Viral/epidemiology , Pneumonia, Viral/immunology , Seoul/epidemiology , Seroepidemiologic Studies , Young Adult
11.
Nat Commun ; 11(1): 4207, 2020 08 21.
Article in English | MEDLINE | ID: covidwho-724410

ABSTRACT

The rapid spread of coronavirus SARS-CoV-2 greatly threatens global public health but no prophylactic vaccine is available. Here, we report the generation of a replication-incompetent recombinant serotype 5 adenovirus, Ad5-S-nb2, carrying a codon-optimized gene encoding Spike protein (S). In mice and rhesus macaques, intramuscular injection with Ad5-S-nb2 elicits systemic S-specific antibody and cell-mediated immune (CMI) responses. Intranasal inoculation elicits both systemic and pulmonary antibody responses but weaker CMI response. At 30 days after a single vaccination with Ad5-S-nb2 either intramuscularly or intranasally, macaques are protected against SARS-CoV-2 challenge. A subsequent challenge reveals that macaques vaccinated with a 10-fold lower vaccine dosage (1 × 1010 viral particles) are also protected, demonstrating the effectiveness of Ad5-S-nb2 and the possibility of offering more vaccine dosages within a shorter timeframe. Thus, Ad5-S-nb2 is a promising candidate vaccine and warrants further clinical evaluation.


Subject(s)
Betacoronavirus/immunology , Coronavirus Infections/prevention & control , Pandemics/prevention & control , Pneumonia, Viral/prevention & control , Viral Vaccines/administration & dosage , Adenoviridae/genetics , Animals , Antibodies, Neutralizing/blood , Antibodies, Viral/blood , Coronavirus Infections/immunology , Dose-Response Relationship, Immunologic , Female , HEK293 Cells , Humans , Immunity, Cellular , Macaca mulatta , Male , Mice , Mice, Inbred BALB C , Pneumonia, Viral/immunology , Respiratory System/pathology , Respiratory System/virology , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/immunology , Vaccines, Synthetic/administration & dosage
12.
J Coll Physicians Surg Pak ; 30(7): 735-739, 2020 Jul.
Article in English | MEDLINE | ID: covidwho-722270

ABSTRACT

OBJECTIVE: To find out the sero-prevalence of COVID-19 IgG antibodies among policemen performing duties at high risk areas of Lahore, Pakistan. STUDY DESIGN: Cross-sectional, observational study. PLACE AND DURATION OF STUDY: Chughtai Lab Lahore from 20th to 30th May 2020. METHODOLOGY: One hundred and fifty-four young policemen (mean age 27.1 ±3.8 years) were included in the study after written consent. Squad officers who had any sign of acute respiratory infection were excluded from the study. The participants were asked to fill a questionnaire regarding nature of exposure with the infected cases, kind of personal protective equipment they are provided with and living arrangements. Three ml of blood samples were collected from the participants and immediately sent to the lab for analysis. COVID-19 IgG antibodies were analysed using chemiluminescence immunoassay method on Architect Ci8200 (Abbott). SPSS 23.0 was used for data analysis. RESULTS: All participants were males and mean age was 27.1 ±3.8 years. Out of 154 squad members, 24 were reactive for COVID-19 IgG antibodies and performing duties at the areas of high virus exposure. None of COVID-19 IgG reactive cases exhibited symptoms and most of them performed duties at high risk areas with only masks provided as personal protective equipment. Only 10% of the participants who were exposed to confirmed cases of COVID-19 were found to have anti-COVID IgG. CONCLUSION: COVID-19 IgG antibody reactive cases may not show any symptoms. Police force is at high risk of exposure. Serosurveys can help to find the spread of infection in the community and aid in planning healthcare strategies. Key Words: COVID-19, SARS CoV-2, Seroprevalence, Pandemic, Asymptomatic cases.


Subject(s)
Betacoronavirus/immunology , Coronavirus Infections/diagnosis , Coronavirus Infections/immunology , Immunoglobulin G/blood , Pneumonia, Viral/diagnosis , Pneumonia, Viral/immunology , Police , Adult , Antibodies, Viral/blood , Asymptomatic Infections , Clinical Laboratory Techniques , Coronavirus Infections/blood , Coronavirus Infections/epidemiology , Cross-Sectional Studies , Female , Humans , Male , Pakistan , Pandemics , Pneumonia, Viral/blood , Pneumonia, Viral/epidemiology , Seroepidemiologic Studies , Young Adult
13.
PLoS One ; 15(8): e0237833, 2020.
Article in English | MEDLINE | ID: covidwho-717610

ABSTRACT

OBJECTIVE: Serological testing is needed to investigate the extent of transmission of SARS-CoV-2 from front-line essential workers to their household members. However, the requirement for serum/plasma limits serological testing to clinical settings where it is feasible to collect and process venous blood. To address this problem we developed a serological test for SARS-CoV-2 IgG antibodies that requires only a single drop of finger stick capillary whole blood, collected in the home and dried on filter paper (dried blood spot, DBS). We describe assay performance and demonstrate its utility for remote sampling with results from a community-based study. METHODS: An ELISA to the receptor binding domain of the SARS-CoV-2 spike protein was optimized to quantify IgG antibodies in DBS. Samples were self-collected from a community sample of 232 participants enriched with health care workers, including 30 known COVID-19 cases and their household members. RESULTS: Among 30 individuals sharing a household with a virus-confirmed case of COVID-19, 80% were seropositive. Of 202 community individuals without prior confirmed acute COVID-19 diagnoses, 36% were seropositive. Of documented convalescent COVID-19 cases from the community, 29 of 30 (97%) were seropositive for IgG antibodies to the receptor binding domain. CONCLUSION: DBS ELISA provides a minimally-invasive alternative to venous blood collection. Early analysis suggests a high rate of transmission among household members. High rates of seroconversion were also noted following recovery from infection. Serological testing for SARS-CoV-2 IgG antibodies in DBS samples can facilitate seroprevalence assessment in community settings to address epidemiological questions, monitor duration of antibody responses, and assess if antibodies against the spike protein correlate with protection from reinfection.


Subject(s)
Betacoronavirus/immunology , Coronavirus Infections/diagnosis , Coronavirus Infections/epidemiology , Dried Blood Spot Testing , Family Characteristics , Health Personnel , Pneumonia, Viral/diagnosis , Pneumonia, Viral/epidemiology , Serologic Tests/methods , Adolescent , Adult , Aged , Antibodies, Viral/blood , Coronavirus Infections/transmission , Coronavirus Infections/virology , Enzyme-Linked Immunosorbent Assay , Female , Humans , Immunoglobulin G/blood , Male , Middle Aged , Pandemics , Pneumonia, Viral/transmission , Pneumonia, Viral/virology , Seroepidemiologic Studies , Spike Glycoprotein, Coronavirus/immunology , Young Adult
14.
Euro Surveill ; 25(32)2020 08.
Article in English | MEDLINE | ID: covidwho-717669

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 viral load in the upper respiratory tract peaks around symptom onset and infectious virus persists for 10 days in mild-to-moderate coronavirus disease (n = 324 samples analysed). RT-PCR cycle threshold (Ct) values correlate strongly with cultivable virus. Probability of culturing virus declines to 8% in samples with Ct > 35 and to 6% 10 days after onset; it is similar in asymptomatic and symptomatic persons. Asymptomatic persons represent a source of transmissible virus.


Subject(s)
Antibodies, Viral/blood , Coronavirus Infections/diagnosis , Coronavirus/genetics , Coronavirus/pathogenicity , Pandemics , Pneumonia, Viral/diagnosis , RNA, Viral/genetics , Virus Shedding/physiology , Asymptomatic Infections , Betacoronavirus , Clinical Laboratory Techniques , Coronavirus/isolation & purification , Coronavirus Infections/epidemiology , Coronavirus Infections/virology , England/epidemiology , Humans , Pneumonia, Viral/epidemiology , Pneumonia, Viral/virology , Reverse Transcriptase Polymerase Chain Reaction , Serologic Tests , Viral Load , Virus Shedding/genetics
16.
MMW Fortschr Med ; 162(14): 44-46, 2020 08.
Article in German | MEDLINE | ID: covidwho-710032

ABSTRACT

Patients with newly diagnosed COVID-19 (coronavirus disease 2019) develop antibodies against SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2). To date, few data have been obtained of the prevalence of SARS-CoV-2-antibodies in general population and in asymptomatic outpatients in Germany.From March 26 to June 4 2020, 415 asymptomatic outpatients were tested prospectively in Northrhine-Westfalia (Germany), to detect SARS-CoV-2-IgG-antibodies. In case of a positive result, anti-SARS-CoV-2-IgA was determined additionally.5 of 415 asymptomatic outpatients had positive SARS-CoV-2-IgG-antibodies with a calculated prevalence of 1.2%. Reference range of anti-SARS-CoV-2-IgA and IgG was defined as ratio for negative < 0.8, borderline 0.8-1.1 and > 1.1 positive. The mean concentration of SARS-CoV-2-IgG-antibodies of the positive 5 outpatients was lower than in symptomatic patients with COVID-19 (n = 12) and positive PCR of SARS-CoV-2 (3.04 ± 2.58 versus 8.05 ± 6.70; p = 0.002). 4 of 5 patients had elevated SARS-CoV-2-IgA-antibodies (1.61 ± 0.82). In 408 screening-outpatients with negative anti-SARS-CoV-2-ELISA-IgG (< 0.8), the mean ratio was 0.25 ± 0.13. Two patients were in the borderline range (0.83 and 0.86).The prevalence of 1.2% of SARS-CoV-2-IgG-antibodies and consequently the rate of infection in asymptomatic outpatients in Northrhine-Westfalia (Germany) is low. The impact of virus neutralisation by antibodies and consequently immunization is the challenge of further investigations.


Subject(s)
Antibodies, Viral/blood , Asymptomatic Infections , Coronavirus Infections/diagnosis , Immunoglobulin G/blood , Pneumonia, Viral/diagnosis , Betacoronavirus , Germany , Humans , Immunoglobulin A/blood , Outpatients , Pandemics , Prevalence
17.
J Infect Dis ; 222(7): 1086-1089, 2020 09 01.
Article in English | MEDLINE | ID: covidwho-709281

ABSTRACT

The recent development and regulatory approval of a variety of serological assays indicating the presence of antibodies against severe acute respiratory syndrome coronavirus 2 has led to rapid and widespread implementation of seroprevalence studies. Accurate estimates of seroprevalence are needed to model transmission dynamics and estimate mortality rates. Furthermore, seroprevalence levels in a population help guide policy surrounding reopening efforts. The literature to date has focused heavily on issues surrounding the quality of seroprevalence tests and less on the sampling methods that ultimately drive the representativeness of resulting estimates. Seroprevalence studies based on convenience samples are being reported widely and extrapolated to larger populations for the estimation of total coronavirus disease 2019 (COVID-19) infections, comparisons of prevalence across geographic regions, and estimation of mortality rates. In this viewpoint, we discuss the pitfalls that can arise with the use of convenience samples and offer guidance for moving towards more representative and timely population estimates of COVID-19 seroprevalence.


Subject(s)
Antibodies, Viral/blood , Betacoronavirus/immunology , Coronavirus Infections/epidemiology , Pneumonia, Viral/epidemiology , Severe Acute Respiratory Syndrome/epidemiology , Coronavirus Infections/transmission , Coronavirus Infections/virology , Humans , Pandemics , Pneumonia, Viral/transmission , Pneumonia, Viral/virology , Population Surveillance , Reproducibility of Results , Sampling Studies , Seroepidemiologic Studies , Severe Acute Respiratory Syndrome/transmission , Severe Acute Respiratory Syndrome/virology
18.
PLoS One ; 15(8): e0236976, 2020.
Article in English | MEDLINE | ID: covidwho-705058

ABSTRACT

SARS-CoV-2 started causing infections in humans in late 2019 and has spread rapidly around the world. While the number of symptomatically infected and severely ill people is high and has overwhelmed the medical systems of many countries, there is mounting evidence that some of the rapid spread of this virus has been driven by asymptomatic infections. In this study, we use a compartmental mathematical model of a viral epidemic that includes asymptomatic infection to examine the role of asymptomatic individuals in the spread of the infection. We apply the model to epidemics in California, Florida, New York, and Texas, finding that asymptomatic infections far outnumber reported symptomatic infections at the peak of the epidemic in all four states. The model suggests that relaxing of social distancing measures too quickly could lead to a rapid rise in the number of cases, driven in part by asymptomatic infections.


Subject(s)
Asymptomatic Infections/epidemiology , Betacoronavirus/immunology , Coronavirus Infections/epidemiology , Coronavirus Infections/transmission , Models, Theoretical , Pneumonia, Viral/epidemiology , Pneumonia, Viral/transmission , Antibodies, Viral/blood , Coronavirus Infections/blood , Coronavirus Infections/virology , Humans , Infection Control/methods , Pandemics , Pneumonia, Viral/blood , Pneumonia, Viral/virology , Seroepidemiologic Studies , United States/epidemiology
19.
J Infect Dis ; 222(4): 551-555, 2020 07 23.
Article in English | MEDLINE | ID: covidwho-704462

ABSTRACT

We simulated 3 transmission modes, including close-contact, respiratory droplets and aerosol routes, in the laboratory. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can be highly transmitted among naive human angiotensin-converting enzyme 2 (hACE2) mice via close contact because 7 of 13 naive hACE2 mice were SARS-CoV-2 antibody seropositive 14 days after being introduced into the same cage with 3 infected-hACE2 mice. For respiratory droplets, SARS-CoV-2 antibodies from 3 of 10 naive hACE2 mice showed seropositivity 14 days after introduction into the same cage with 3 infected-hACE2 mice, separated by grids. In addition, hACE2 mice cannot be experimentally infected via aerosol inoculation until continued up to 25 minutes with high viral concentrations.


Subject(s)
Betacoronavirus , Coronavirus Infections/transmission , Pneumonia, Viral/transmission , Aerosols , Anal Canal/virology , Animals , Antibodies, Viral/blood , Betacoronavirus/genetics , Betacoronavirus/immunology , Betacoronavirus/isolation & purification , Chlorocebus aethiops , Female , Humans , Immunoglobulin G/blood , Lung/pathology , Lung/virology , Male , Mice , Mice, Transgenic , Pandemics , Peptidyl-Dipeptidase A/genetics , Pharynx/virology , RNA, Viral/isolation & purification , Respiratory System/virology , Risk , Specific Pathogen-Free Organisms , Time Factors , Vero Cells , Viral Load , Weight Loss
20.
J Exp Med ; 217(11)2020 11 02.
Article in English | MEDLINE | ID: covidwho-697830

ABSTRACT

The emergence of SARS-CoV-2 and the ensuing explosive epidemic of COVID-19 disease has generated a need for assays to rapidly and conveniently measure the antiviral activity of SARS-CoV-2-specific antibodies. Here, we describe a collection of approaches based on SARS-CoV-2 spike-pseudotyped, single-cycle, replication-defective human immunodeficiency virus type-1 (HIV-1), and vesicular stomatitis virus (VSV), as well as a replication-competent VSV/SARS-CoV-2 chimeric virus. While each surrogate virus exhibited subtle differences in the sensitivity with which neutralizing activity was detected, the neutralizing activity of both convalescent plasma and human monoclonal antibodies measured using each virus correlated quantitatively with neutralizing activity measured using an authentic SARS-CoV-2 neutralization assay. The assays described herein are adaptable to high throughput and are useful tools in the evaluation of serologic immunity conferred by vaccination or prior SARS-CoV-2 infection, as well as the potency of convalescent plasma or human monoclonal antibodies.


Subject(s)
Antibodies, Neutralizing/analysis , Antibodies, Viral/analysis , Betacoronavirus/immunology , Coronavirus Infections/immunology , Immunoassay/methods , Pneumonia, Viral/immunology , Animals , Antibodies, Monoclonal/immunology , Antibodies, Neutralizing/blood , Antibodies, Viral/blood , Betacoronavirus/genetics , Cell Line , Chimera/genetics , Chimera/immunology , Chlorocebus aethiops , Coronavirus Infections/virology , HEK293 Cells , HIV-1/genetics , HIV-1/immunology , Humans , Neutralization Tests/methods , Pandemics , Pneumonia, Viral/virology , Recombination, Genetic , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/immunology , Vero Cells , Vesicular stomatitis Indiana virus/genetics , Vesicular stomatitis Indiana virus/immunology
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