scholarly journals Patterns and persistence of SARS-CoV-2 IgG antibodies in a US metropolitan site

2020 ◽  
Author(s):  
Alexis R. Demonbreun ◽  
Thomas W. McDade ◽  
Lorenzo Pesce ◽  
Lauren A. Vaught ◽  
Nina L. Reiser ◽  
...  
Keyword(s):  
Receptor Binding ◽  
Virus Detection ◽  
Receptor Binding Domain ◽  
Igg Antibodies ◽  
Repeat Testing ◽  
Seropositive Individual ◽  
Significant Difference ◽  
Viral Testing ◽  
Blood Spot ◽  
Modest Correlation

AbstractBackgroundEstimates of seroprevalence to SARS-CoV-2 vary widely. We ascertained IgG levels across a single US metropolitan site, Chicago, over the 2020 summer, a period when restrictions on activities had been lifted.MethodsWe utilized a self-sampled dried blood spot assay to quantitatively monitor antibodies to the receptor binding domain (RBD) of the spike glycoprotein of SARS-CoV-2 in 1545 participants, with return of blood spot cards either by mail or in-person drop-off.ResultsSeroprevalence was 19.8%, with no significant difference between method of contact, or between essential and non-essential workers. Only a small number (1.2%) of participants reported having had a diagnosis of COVID-19 based on virus detection, consistent with a 16-fold greater exposure to SARS-CoV-2 measured by serology than detected by viral testing. Only a modest correlation was observed between having antibodies to SARS-CoV-2 nucleocapsid compared to RBD, with many only having detectable anti-RBD antibodies. From a subset of those who participated in repeat testing, three-quarters of seropositive individuals retained detectable antibodies for at least 120 days. One seropositive individual experienced a strong boost in IgG levels following a symptomatic illness, suggestive of potential re-exposure.ConclusionsThese data underscore the importance of a self-collected, quantitative assay with adequate sensitivity to detect antibodies at the lower levels among non-hospitalized persons with community-acquired exposure to COVID-19.

scholarly journals High seroprevalence for SARS-CoV-2 among household members of essential workers detected using a dried blood spot assay

2020 ◽  
Author(s):  
Thomas W. McDade ◽  
Elizabeth M. McNally ◽  
Aaron S. Zelikovich ◽  
Richard D’Aquila ◽  
Brian Mustanski ◽  
...  
Keyword(s):  
Receptor Binding ◽  
Venous Blood ◽  
Binding Domain ◽  
Spike Protein ◽  
Dried Blood Spot ◽  
Receptor Binding Domain ◽  
Serological Testing ◽  
Igg Antibodies ◽  
Household Members ◽  
Blood Spot

AbstractObjectiveSerological 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).MethodsAn 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.ResultsAmong 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.ConclusionDBS 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 SARSCoV-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.

scholarly journals 480 Preliminary evaluation of a novel coronavirus vaccine (CORVax) using electroporation of plasmid DNA encoding a stabilized prefusion SARS-CoV-2 spike protein alone or with transfection of plasmid IL-12

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A514-A514
Author(s):  
Shawn Jensen ◽  
Christopher Twitty ◽  
Christopher Paustian ◽  
Madelein Laws ◽  
Glenna McDonnell ◽  
...  
Keyword(s):  
Immune Responses ◽  
Receptor Binding ◽  
Binding Domain ◽  
Tumor Rejection ◽  
Spike Protein ◽  
Preliminary Evaluation ◽  
List Type ◽  
Receptor Binding Domain ◽  
Igg Antibodies ◽  
Viral Neutralization

BackgroundSARS-CoV-2 (CoV2) has precipitated a global pandemic and the effectiveness of standard vaccine strategies to induce potent and persistent immunity to CoV2 is in question, particularly for the elderly. This problem is not dissimilar to what we have struggled with in our quest to induce immunity to cancer antigens, where vaccine-induced anti-cancer immune responses can be weak. Here, we describe a novel vaccine approach which leverages electroporation (EP) of a plasmid encoding a prefusion stabilized CoV2 spike protein (CORVax). As IL-12 has been shown to augment the efficacy of immunotherapy in aged mice,1 we have initiated studies to evaluate if plasmid IL-12 (TAVO™) can similarly augment anti-CoV2 immune responses in young mice and have planned studies in aged animals.MethodsA prefusion stabilized CoV2 spike plasmid expression vector was constructed, a master cell bank generated and clinical-grade plasmid manufactured. C57BL/6 and BALB/c were vaccinated via intramuscular (IM) and/or intradermal (ID) injection followed immediately by EP of plasmids encoding the CoV2 spike protein with or without plasmid-encoded murine IL-12 on days 1 and 14 or 21. Mice were followed for >120 days to assess safety. Splenocytes and serum were harvested at different time points to interrogate virus-specific cellular responses as well anti-spike IgG1/IgG2 antibody titers. A surrogate viral neutralization test (sVNT) assessed serum blockade of soluble hACE2R binding to immobilized CoV2 spike.ResultsPreliminary data shows that EP of CORVax alone or combined with IL-12 was safe. EP of CORVax was able to elicit anti-Spike IgG antibodies (IC50 = 1/2112), as well as IgG antibodies targeting the receptor binding domain of the Spike protein (IC50 = 1/965) approximately 40 days after the booster vaccination. In 2 of 2 experiments, CORVax combined with IL-12 significantly (P<0.0001) increased the sVNT titers at 2 months, but this benefit was lost by 3 months.ConclusionsEarly preclinical data shows that EP of CORVax can induce IgG responses to CoV2 Spike and the receptor binding domain (RBD) as well as apparent viral neutralizing activity. The addition of IL-12, at least transiently, increased sVNT titer. We plan to investigate alternate vaccine boosting strategies while extending these studies into aged animals and initiate a clinical trial in the near future.ReferencesRuby CE, Weinberg AD. OX40-Enhanced tumor rejection and effector T cell differentiation decreases with age. J Immunol2009;182:1481–9. https://doi.org/10.4049/jimmunol.182.3.1481.

scholarly journals Immunogenicity Studies of Plant-Produced SARS-CoV-2 Receptor Binding Domain-Based Subunit Vaccine Candidate with Different Adjuvant Formulations

Vaccines ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 744
Author(s):  
Konlavat Siriwattananon ◽  
Suwimon Manopwisedjaroen ◽  
Balamurugan Shanmugaraj ◽  
Eakachai Prompetchara ◽  
Chutitorn Ketloy ◽  
...  
Keyword(s):  
Immune Response ◽  
Receptor Binding ◽  
Neutralizing Antibodies ◽  
Lipid A ◽  
Binding Domain ◽  
Poly I:C ◽  
Receptor Binding Domain ◽  
Monophosphoryl Lipid A ◽  
Polycytidylic Acid ◽  
Significant Difference

Due to the rapid transmission of the coronavirus disease 2019 (COVID-19) causing serious public health problems and economic burden, the development of effective vaccines is a high priority for controlling the virus spread. Our group has previously demonstrated that the plant-produced receptor-binding domain (RBD) of SARS-CoV-2 fused with Fc of human IgG was capable of eliciting potent neutralizing antibody and cellular immune responses in animal studies, and the immunogenicity could be improved by the addition of an alum adjuvant. Here, we performed a head-to-head comparison of different commercially available adjuvants, including aluminum hydroxide gel (alum), AddaVax (MF59), monophosphoryl lipid A from Salmonella minnesota R595 (mPLA-SM), and polyinosinic-polycytidylic acid (poly(I:C)), in mice by combining them with plant-produced RBD-Fc, and the differences in the immunogenicity of RBD-Fc with different adjuvants were evaluated. The specific antibody responses in terms of total IgG, IgG1, and IgG2a subtypes and neutralizing antibodies, as well as vaccine-specific T-lymphocyte responses, induced by the different tested adjuvants were compared. We observed that all adjuvants tested here induced a high level of total IgG and neutralizing antibodies, but mPLA-SM and poly (I:C) showed the induction of a balanced IgG1 and IgG2a (Th2/Th1) immune response. Further, poly (I:C) significantly increased the frequency of IFN-γ-expressing cells compared with control, whereas no significant difference was observed between the adjuvanted groups. This data revealed the adjuvants’ role in enhancing the immune response of RBD-Fc vaccination and the immune profiles elicited by different adjuvants, which could prove helpful for the rational development of next-generation SARS-CoV-2 RBD-Fc subunit vaccines. However, additional research is essential to further investigate the efficacy and safety of this vaccine formulation before clinical trials.

scholarly journals Development of a high-throughput SARS-CoV-2 antibody testing pathway using dried blood spot specimens

2020 ◽  
pp. 000456322098110
Author(s):  
Stuart J Moat ◽  
Wioleta M Zelek ◽  
Emily Carne ◽  
Mark J Ponsford ◽  
Kathryn Bramhall ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Receptor Binding ◽  
Binding Domain ◽  
Dried Blood Spot ◽  
Enzyme Linked Immunosorbent Assay ◽  
Receptor Binding Domain ◽  
Chain Reaction ◽  
Deming Regression ◽  
Polymerase Chain ◽  
Blood Spot

Background Serological assays for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) have roles in seroepidemiology, convalescent plasma-testing, antibody durability and vaccine studies. Currently, SARS-CoV-2 serology is performed using serum/plasma collected by venepuncture. Dried blood spot (DBS) testing offers significant advantages as it is minimally invasive, avoids venepuncture with specimens being mailed to the laboratory. Methods A pathway utilizing a newborn screening laboratory infrastructure was developed using an enzyme-linked immunosorbent assay to detect IgG antibodies against the receptor-binding domain of the SARS-CoV-2 spike protein in DBS specimens. Paired plasma and DBS specimens from SARS-CoV-2 antibody-positive and -negative subjects and polymerase chain reaction positive subjects were tested. DBS specimen stability, effect of blood volume and punch location were also evaluated. Results DBS specimens from antibody-negative ( n = 85) and -positive ( n = 35) subjects and polymerase chain reaction positive subjects ( n = 11) had a mean (SD; range) optical density (OD) of 0.14 (0.046; 0.03–0.27), 0.98 (0.41; 0.31–1.64) and 1.12 (0.37; 0.49–1.54), respectively. An action value OD >0.28 correctly assigned all cases. The weighted Deming regression for comparison of the DBS and the plasma assay yielded: y = 0.004041 + 1.005 x, r = 0.991, Sy/ x 0.171, n = 82. Extraction efficiency of antibodies from DBS specimens was >99%. DBS specimens were stable for at least 28 days at ambient room temperature and humidity. Conclusions SARS-CoV-2 IgG receptor-binding domain antibodies can be reliably detected in DBS specimens. DBS serological testing offers lower costs than either point of care or serum/plasma assays that require patient travel, phlebotomy and hospital/clinic resources; the development of a DBS assay may be particularly important for resource poor settings.

scholarly journals Persistence of serum and saliva antibody responses to SARS-CoV-2 spike antigens in patients with COVID-19

2020 ◽  
Vol 5 (52) ◽  
pp. eabe5511
Author(s):  
Baweleta Isho ◽  
Kento T. Abe ◽  
Michelle Zuo ◽  
Alainna J. Jamal ◽  
Bhavisha Rathod ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Antibody Response ◽  
Receptor Binding ◽  
Antibody Responses ◽  
Spike Protein ◽  
Receptor Binding Domain ◽  
Igg Antibodies ◽  
Surrogate Measure ◽  
Antibody Levels ◽  
Negative Controls

Although the antibody response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been extensively studied in blood, relatively little is known about the antibody response in saliva and its relationship to systemic antibody levels. Here, we profiled by enzyme-linked immunosorbent assays (ELISAs) immunoglobulin G (IgG), IgA, and IgM responses to the SARS-CoV-2 spike protein (full-length trimer) and its receptor binding domain (RBD) in serum and saliva of acute and convalescent patients with laboratory-diagnosed coronavirus disease 2019 (COVID-19) ranging from 3 to 115 days postsymptom onset (PSO), compared with negative controls. Anti–SARS-CoV-2 antibody responses were readily detected in serum and saliva, with peak IgG levels attained by 16 to 30 days PSO. Longitudinal analysis revealed that anti–SARS-CoV-2 IgA and IgM antibodies rapidly decayed, whereas IgG antibodies remained relatively stable up to 105 days PSO in both biofluids. Last, IgG, IgM, and, to a lesser extent, IgA responses to spike and RBD in the serum positively correlated with matched saliva samples. This study confirms that serum and saliva IgG antibodies to SARS-CoV-2 are maintained in most of the patients with COVID-19 for at least 3 months PSO. IgG responses in saliva may serve as a surrogate measure of systemic immunity to SARS-CoV-2 based on their correlation with serum IgG responses.

scholarly journals Fluorescence signatures of SARS CoV-2 spike S1 proteins and an human ACE-2: excitation-emission maps and fluorescence lifetimes

2021 ◽  
Author(s):  
Jonas Grzesiak ◽  
Lea Fellner ◽  
Karin Grünewald ◽  
Christoph Kölbl ◽  
Arne Walter ◽  
...  
Keyword(s):  
Receptor Binding ◽  
Virus Detection ◽  
High Sensitivity ◽  
Binding Domain ◽  
Receptor Binding Domain ◽  
Fluorescence Lifetimes ◽  
Comprehensive Knowledge ◽  
Clean Environment ◽  
Complex Protein ◽  
One Year

Fast and reliable detection of infectious virus loads of the SARS CoV-2 virus is still an important issue even after more than one year of the pandemic's outbreak. The spike protein's S1 subunit (including its receptor-binding domain) and human angiotensin-converting enzyme 2 (hACE2) are known as key players in the reproduction mechanism of the SARS CoV-2 virus. Because of its high sensitivity and simple application, fluorescence spectroscopy is promising to meet the sensitivity requirements for a virus detection in a clean environment. In such highly complex protein systems, a comprehensive knowledge of fluorescence data is presumed in order to evaluate the specificity of the spectra with respect to a possible detection. This includes full featured information on the fluorescence process, i. e. wavelength and time-dependent data. In this work, fluorescence spectral excitation-emission maps of the involved proteins are presented, namely the S1 part of the spike protein and its receptor-binding domain as well as the hACE2 enzyme. In addition, measurements of fluorescence lifetimes of the proteins are presented and analyzed by a bi-exponential kinetic approach.

scholarly journals Identification of IgG antibody response to SARS-CoV-2 spike protein and its receptor binding domain does not predict rapid recovery from COVID-19

2020 ◽  
Author(s):  
Kathleen M. McAndrews ◽  
Dara P. Dowlatshahi ◽  
Janine Hensel ◽  
Luis L. Ostrosky-Zeichner ◽  
Ramesh Papanna ◽  
...  
Keyword(s):  
Health Care ◽  
Antibody Response ◽  
Receptor Binding ◽  
Binding Domain ◽  
Spike Protein ◽  
Quantitative Detection ◽  
Receptor Binding Domain ◽  
Igg Antibodies ◽  
Spike Glycoprotein ◽  
The World

AbstractDiagnostic testing and evaluation of patient immunity against the novel severe acute respiratory syndrome (SARS) corona virus that emerged last year (SARS-CoV-2) are essential for health and economic crisis recovery of the world. It is suggested that potential acquired immunity against SARS-CoV-2 from prior exposure may be determined by detecting the presence of circulating IgG antibodies against viral antigens, such as the spike glycoprotein and its receptor binding domain (RBD). Testing our asymptomatic population for evidence of COVID-19 immunity would also offer valuable epidemiologic data to aid health care policies and health care management. Currently, there are over 100 antibody tests that are being used around the world without approval from the FDA or similar regulatory bodies, and they are mostly for rapid and qualitative assessment, with different degrees of error rates. ELISA-based testing for sensitive and rigorous quantitative assessment of SARS-CoV-2 antibodies can potentially offer mechanistic insights into the COVID-19 disease and aid communities uniquely challenged by limited financial resources and access to commercial testing products. Employing recombinant SARS-CoV-2 RBD and spike protein generated in the laboratory, we devised a quantitative ELISA for the detection of circulating serum antibodies. Serum from twenty SARS-CoV-2 RT-PCR confirmed COVID-19 hospitalized patients were used to detect circulating IgG titers against SARS-CoV-2 spike protein and RBD. Quantitative detection of IgG antibodies to the spike glycoprotein or the RBD in patient samples was not always associated with faster recovery, compared to patients with borderline antibody response to the RBD. One patient who did not develop antibodies to the RBD completely recovered from COVID-19. In surveying 99 healthy donor samples (procured between 2017-February 2020), we detected RBD antibodies in one donor from February 2020 collection with three others exhibiting antibodies to the spike protein but not the RBD. Collectively, our study suggests that more rigorous and quantitative analysis, employing large scale samples sets, is required to determine whether antibodies to SARS-CoV-2 spike protein or RBD is associated with protection from COVID-19 disease. It is also conceivable that humoral response to SARS-CoV-2 spike protein or RBD works in association with adaptive T cell response to determine clinical sequela and severity of COVID-19 disease.

scholarly journals Increasing IgG antibodies to SARS-CoV-2 in asymptomatic blood donors through the second COVID-19 wave in Karachi associated with exposure and immunity in the population

2021 ◽  
Author(s):  
Muhammad Hasan ◽  
Bushra Moiz ◽  
Shama Qiaser ◽  
Zara Ghous ◽  
Areeba Hussain ◽  
...  
Keyword(s):  
Receptor Binding ◽  
Protective Immunity ◽  
Blood Donors ◽  
Blood Donation ◽  
Clinical Information ◽  
Clinical History ◽  
University Hospital ◽  
Receptor Binding Domain ◽  
Igg Antibodies ◽  
Pandemic Wave

Abstract Introduction One million cases of COVID-19 have been reported in Pakistan until August 1, 2021. However, SARS-CoV-2 PCR testing capacity is limited, and the true level of SARS-CoV-2 infections is unknown. Most individuals have asymptomatic or mild COVID-19 and remain undiagnosed. Volunteer healthy blood donors can be a control population for assessment of SARS-CoV-2 exposure. We determined COVID-19 seroprevalence during the second pandemic wave in Karachi. Materials and Methods We enrolled 558 healthy blood donors at the Aga Khan University Hospital blood bank between December 2020 and February 2021. Serum IgG reactivity were measured to spike and receptor binding domain (RBD) proteins. Clinical history was taken from individuals with a positive IgG result. Results Of the 558 study subjects, 553 (99.1%) were males and 5 (0.9%) were females with a mean (± SD) age of 29.0 ± 7.4 years (range 17–53 years). Positive IgG responses to spike were detected in 298/558 blood donors (53.4%). Of the spike IgG positive cases, 93/298 individuals (31.2%) had IgG antibodies to RBD. Clinical information was available for 63.7% of spike IgG positive cases. Of these, 37% had flu-like symptoms, 25% had travelled, individuals had contact with COVID-19 suspected (18%) or confirmed (15%) cases. Within the year prior to blood donation, 29% of individuals had laboratory confirmed COVID-19. Conclusions The seroprevalence of 53.4% of IgG antibodies to spike and 31.2% of IgG to RBD of SARS-CoV-2 in healthy blood donors indicates high rates of exposure and gives insights into protective immunity in the population.

scholarly journals Serological Profile of Convalescent COVID-19 Patients at an Infectious Diseases Hospital in Nigeria

2021 ◽  
pp. 16-22
Author(s):  
Adeola Fowotade ◽  
Temitayo Oluwaseun Fasuyi ◽  
Ewean Chukwuma Omoruyi ◽  
Temitope Oluwagbenga Alonge
Keyword(s):  
Infectious Diseases ◽  
Immune Responses ◽  
Receptor Binding ◽  
Lateral Flow ◽  
Receptor Binding Domain ◽  
Igg Antibodies ◽  
Rt Pcr ◽  
Ct Value ◽  
Lateral Flow Assays ◽  
The Relationship

Background: IgG antibodies may serve as promising targets to detect and evaluate immune responses against the SARS-CoV-2 virus. Both IgA and IgM antibodies target the spike protein’s receptor binding domain and are rapidly decayed, while IgG antibodies remain relatively stable for longer periods in COVID-19 patients. Objectives: The current study was designed to detect the presence of SARS-CoV-2 antibodies among convalescent COVID-19 patients and to evaluate the relationship between these antibodies, the symptom grade and their baseline Cycle Threshold (CT) by RT-PCR. Methods: Eighty-nine convalescent COVID-19 patients on admission were recruited and tested until negative by RT-PCR. Sera obtained from participants were screened for SARS-CoV-2 IgM and IgG antibodies using rapid lateral flow assays. Results: It was observed that 93,3% and 77,5% respectively had IgM and IgG antibodies against the S1 protein of SARS-CoV-2.  Majority (74,0%) presented with mild COVID-19 symptoms with a mean RT-PCR Ct value of 31,4. Conclusion: Convalescent COVID-19 patients develop a fairly good level of IgG antibodies. The antibody status is not dependent on CT value or symptom grade. However, there was a significant correlation between baseline CT and time taken to test negative by RT-PCR.

Sign in / Sign up

Export Citation Format

Share Document