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2.
PLoS One ; 16(3): e0247797, 2021.
Article in English | MEDLINE | ID: covidwho-1605332

ABSTRACT

Since the initial identification of the novel coronavirus SARS-CoV-2 in December of 2019, researchers have raced to understand its pathogenesis and begun devising vaccine and treatment strategies. An accurate understanding of the body's temporal immune response against SARS-CoV-2 is paramount to successful vaccine development and disease progression monitoring. To provide insight into the antibody response against SARS-CoV-2, plasma samples from 181 PCR-confirmed COVID-19 patients collected at various timepoints post-symptom onset (PSO) were tested for the presence of anti-SARS-CoV-2 IgM and IgG antibodies via lateral flow. Additionally, 21 donors were tracked over time to elucidate patient-specific immune responses. We found sustained levels of anti-SARS-CoV-2 antibodies past 130 days PSO, with 99% positivity observed at 31-60 days PSO. By 61-90 days PSO, the percentage of IgM-/IgG+ results were nearly equal to that of IgM+/IgG+ results, demonstrating a shift in the immune response with a decrease in IgM antibody levels. Results from this study not only provide evidence that the antibody response to COVID-19 can persist for over 4 months, but also demonstrates the ability of Easy Check™ to monitor seroconversion and antibody response of patients. Easy Check was sufficiently sensitive to detect antibodies in patient samples as early as 1-4 days PSO with 86% positivity observed at 5-7 days PSO. Further studies are required to determine the longevity and efficacy of anti-SARS-CoV-2 antibodies, and whether they are protective against re-infection.


Subject(s)
Antibodies, Viral/blood , COVID-19/blood , Immunoglobulin G/blood , Immunoglobulin M/blood , SARS-CoV-2/immunology , Adolescent , Adult , Aged , Aged, 80 and over , Antibodies, Viral/immunology , COVID-19/immunology , COVID-19 Serological Testing/instrumentation , COVID-19 Serological Testing/methods , Equipment Design , Female , Humans , Immunoglobulin G/immunology , Immunoglobulin M/immunology , Longitudinal Studies , Male , Middle Aged , SARS-CoV-2/isolation & purification , Young Adult
3.
PLoS One ; 17(1): e0262162, 2022.
Article in English | MEDLINE | ID: covidwho-1605852

ABSTRACT

Analysis of convalescent plasma derived from individuals has shown that IgG3 has the most important role in binding to SARS-CoV-2 antigens; however, this has not yet been confirmed in large studies, and the link between binding and neutralization has not been confirmed. By analyzing plasma pools consisting of 247-567 individual convalescent donors, we demonstrated the binding of IgG3 and IgM to Spike-1 protein and the receptor-binding domain correlates strongly with viral neutralization in vitro. Furthermore, despite accounting for only approximately 12% of total immunoglobulin mass, collectively IgG3 and IgM account for approximately 80% of the total neutralization. This may have important implications for the development of potent therapies for COVID-19, as it indicates that hyperimmune globulins or convalescent plasma donations with high IgG3 concentrations may be a highly efficacious therapy.


Subject(s)
Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , COVID-19/blood , COVID-19/immunology , Convalescence , Immunoglobulin G/immunology , Animals , Antibodies, Neutralizing/blood , Antibodies, Viral/blood , Chlorocebus aethiops , Enzyme-Linked Immunosorbent Assay , Humans , Immunoglobulin G/blood , Immunoglobulin M/blood , Immunoglobulin M/immunology , SARS-CoV-2/physiology , Vero Cells
4.
Viruses ; 13(12)2021 12 20.
Article in English | MEDLINE | ID: covidwho-1580419

ABSTRACT

A microarray-based assay to detect IgG and IgM antibodies against betacoronaviruses (SARS-CoV-2, SARS, MERS, OC43, and HKU1), other respiratory viruses and type I interferons (IFN-Is) was developed. This multiplex assay was applied to track antibody cross-reactivity due to previous contact with similar viruses and to identify antibodies against IFN-Is as the markers for severe COVID-19. In total, 278 serum samples from convalescent plasma donors, COVID-19 patients in the intensive care unit (ICU) and patients who recovered from mild/moderate COVID-19, vaccine recipients, prepandemic and pandemic patients with autoimmune endocrine disorders, and a heterogeneous prepandemic cohort including healthy individuals and chronically ill patients were analyzed. The anti-SARS-CoV-2 microarray results agreed well with the ELISA results. Regarding ICU patients, autoantibodies against IFN-Is were detected in 10.5% of samples, and 10.5% of samples were found to simultaneously contain IgM antibodies against more than two different viruses. Cross-reactivity between IgG against the SARS-CoV-2 nucleocapsid and IgG against the OC43 and HKU1 spike proteins was observed, resulting in positive signals for the SARS-CoV-2 nucleocapsid in prepandemic samples from patients with autoimmune endocrine disorders. The presence of IgG against the SARS-CoV-2 nucleocapsid in the absence of IgG against the SARS-CoV-2 spike RBD should be interpreted with caution.


Subject(s)
Antibodies, Viral/immunology , Interferon Type I/immunology , SARS-CoV-2/immunology , Viruses/immunology , Antibodies, Viral/blood , Antigens, Viral/immunology , Autoantibodies/blood , Autoantibodies/immunology , COVID-19/immunology , COVID-19 Serological Testing , Cross Reactions , Humans , Immunoglobulin G/blood , Immunoglobulin G/immunology , Immunoglobulin M/blood , Immunoglobulin M/immunology , Protein Array Analysis , Respiratory Tract Diseases/immunology , Respiratory Tract Diseases/virology , Viruses/classification
5.
Nutrients ; 13(12)2021 Dec 02.
Article in English | MEDLINE | ID: covidwho-1551616

ABSTRACT

A single-center, randomized, double-blind, placebo-controlled study was conducted in 72 volunteers who received a synergistic combination of yeast-based ingredients with a unique ß-1,3/1,6-glucan complex and a consortium of heat-treated probiotic Saccharomyces cerevisiae rich in selenium and zinc (ABB C1®) or placebo on the next day after getting vaccinated against influenza (Chiromas®) (n = 34) or the COVID-19 (Comirnaty®) (n = 38). The duration of treatment was 30 and 35 days for the influenza and COVID-19 vaccine groups, respectively. Mean levels of CD4+T cells increased from 910.7 at baseline to 1000.2 cells/µL after the second dose of the COVID-19 vaccine in the ABB C1® group, whereas there was a decrease from 1055.1 to 929.8 cells/µL in the placebo group. Changes of CD3+T and CD8+T lymphocytes showed a similar trend. In the COVID-19 cohort, the increases in both IgG and IgM were higher in the ABB C1® supplement than in the placebo group. Serum levels of selenium and zinc showed a higher increase in subjects treated with the active product than in those receiving placebo. No serious adverse events related to ABB C1® or tolerance issues were reported. The study findings validate the capacity of the ABB C1® product to stimulate trained immunity.


Subject(s)
COVID-19 Vaccines/administration & dosage , Dietary Supplements , Influenza Vaccines/administration & dosage , Saccharomyces cerevisiae , Selenium/administration & dosage , Zinc/administration & dosage , beta-Glucans/administration & dosage , Antibodies, Viral/immunology , CD4-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/immunology , COVID-19 Vaccines/immunology , Double-Blind Method , Female , Humans , Immunoglobulin G/immunology , Immunoglobulin M/immunology , Influenza Vaccines/immunology , Male , Middle Aged , Selenium/immunology , Zinc/immunology , beta-Glucans/immunology
6.
J Med Virol ; 93(12): 6582-6587, 2021 Dec.
Article in English | MEDLINE | ID: covidwho-1544305

ABSTRACT

The purpose of this study was to evaluate the SARS-CoV-2 immunoglobulin M/immunoglobulin G (IgM/IgG) rapid antibody test results in symptomatic patients with COVID-19 and their chest computed tomography (CT) data. A total of 320 patients admitted to our hospital for different durations due to COVID-19 were included in the study. Serum samples were obtained within 0-7 days from COVID-19 patients confirmed by reverse-transcription polymerase chain reaction (RT-PCR) and chest CT scan. According to the SARS-CoV-2 RT-PCR results, the patients included in the study were divided into two groups: PCR positive group (n = 46) and PCR negative group (n = 274). The relationship between chest CT and rapid antibody test results were compared statistically. Of the 320 COVID-19 serum samples, IgM, IgG, and IgM/IgG were detected in 8.4%, 0.3%, and 11.6% within 1 week, respectively. IgG/IgM antibodies were not detected in 79.7% of the patients. In the study, 249 (77.8%) of 320 patients had positive chest CT scans. Four (5.6%) of 71 patients with negative chest CT scans had IgM and two (2.8%) were both IgM/IgG positive. IgM was detected in 23 (9.2%), IgG in one (0.4%), and IgM/IgG in 35 (14%) of chest CT scan positive patients. The rate of CT findings in patients with antibody positivity was found to be significantly higher than those with antibody negativity. The results of the present study show the accurate and equivalent performance of serological antibody assays and chest CT in detecting SARS-CoV-2 within 0-7 days from the onset of COVID19 symptoms. When RT-PCR is not available, we believe that the combination of immunochromatographic test and chest CT scan can increase diagnostic sensitivity for COVID-19.


Subject(s)
Antibodies, Viral/blood , COVID-19 Testing/methods , COVID-19/diagnosis , Reverse Transcriptase Polymerase Chain Reaction/methods , Adolescent , Adult , Aged , Aged, 80 and over , Antibodies, Viral/immunology , COVID-19/diagnostic imaging , Female , Humans , Immunoglobulin G/blood , Immunoglobulin G/immunology , Immunoglobulin M/blood , Immunoglobulin M/immunology , Male , Middle Aged , Radiography, Thoracic , Retrospective Studies , Tomography, X-Ray Computed , Young Adult
7.
Pan Afr Med J ; 38: 55, 2021.
Article in French | MEDLINE | ID: covidwho-1547713

ABSTRACT

The first outbreak of epidemic respiratory disease due to unknown etiology was reported in the Chinese city of Wuhan December 2019. The World Health Organization (WHO) firstly used the term "new coronavirus 2019" on December 29, 2019. This pandemic, which is currently called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is a disease caused by SARS-CoV-2. It was subsequently called coronavirus disease 2019 (COVID-19) by the WHO. The purpose of this study was to determine the prevalence of antibodies against SARS-CoV-2 in all employees of the Nouakchott National Hospital Center (CHN). The study was conducted during the week 20/05/2020 to 27/05/2020. It involved 853 employees of all ranks (doctors, pharmacists, nurses, secretaries, security personnel, administrators...) of whom 504 were male and 331 were female, with a sex ratio of 1,52 with an average age of 39 years, ranging from 20 to 60 years. The screening for IgG and IgM antibodies to SARS-CoV-2 was performed using Biotime (Xiamen Biotime Biotechnology Co., Ltd.) immunochromatographic technique. Out of 835 employees included in our study, 14 were positive (1.67%) of whom 12 had IgM and IgG anti-SARS-CoV-2 antibodies and 2 had isolated IgM. Nasopharyngeal swab polymerase chain reaction (PCR) was performed in these 14 patients and was positive in six. While PCR is the gold standard for the diagnosis of SARS-CoV-2, serological tests for SARS-CoV-2 antibodies, in particular rapid tests (RDTs) are a diagnostic complement to COVID-19. They have the advantage of being easy to realize, of being safe both in the laboratories and outside the laboratories. RDTs enabled us to detect asymptomatic SARS-CoV-2 carriers within CHN employees. This allowed for patients management and isolation to protect patients and their environments.


Subject(s)
COVID-19 Testing , COVID-19/diagnosis , Health Personnel , SARS-CoV-2/isolation & purification , Adult , Antibodies, Viral/blood , COVID-19/epidemiology , Female , Humans , Immunoglobulin G/immunology , Immunoglobulin M/immunology , Male , Mauritania/epidemiology , Middle Aged , Serologic Tests/methods , Young Adult
8.
Front Immunol ; 12: 777103, 2021.
Article in English | MEDLINE | ID: covidwho-1528826

ABSTRACT

Background: Data regarding symptoms in the lactating mother-infant dyad and their immune response to COVID-19 mRNA vaccination during lactation are needed to inform vaccination guidelines. Methods: From a prospective cohort of 50 lactating individuals who received mRNA-based vaccines for COVID-19 (mRNA-1273 and BNT162b2), blood and milk samples were collected prior to first vaccination dose, immediately prior to 2nd dose, and 4-10 weeks after 2nd dose. Symptoms in mother and infant were assessed by detailed questionnaires. Anti-SARS-CoV-2 antibody levels in blood and milk were measured by Pylon 3D automated immunoassay and ELISA. In addition, vaccine-related PEGylated proteins in milk were measured by ELISA. Blood samples were collected from a subset of infants whose mothers received the vaccine during lactation (4-15 weeks after mothers' 2nd dose). Results: No severe maternal or infant adverse events were reported in this cohort. Two mothers and two infants were diagnosed with COVID-19 during the study period before achieving full immune response. PEGylated proteins were not found at significant levels in milk after vaccination. After vaccination, levels of anti-SARS-CoV-2 IgG and IgM significantly increased in maternal plasma and there was significant transfer of anti-SARS-CoV-2-Receptor Binding Domain (anti-RBD) IgA and IgG antibodies to milk. Milk IgA levels after the 2nd dose were negatively associated with infant age. Anti-SARS-CoV-2 IgG antibodies were not detected in the plasma of infants whose mothers were vaccinated during lactation. Conclusions: COVID-19 mRNA vaccines generate robust immune responses in plasma and milk of lactating individuals without severe adverse events reported.


Subject(s)
Antibodies, Viral/immunology , COVID-19 Vaccines/administration & dosage , Lactation/immunology , Milk, Human/immunology , SARS-CoV-2/immunology , Adult , Antibodies, Viral/blood , COVID-19/prevention & control , Female , Humans , Immunoglobulin A/immunology , Immunoglobulin G/blood , Immunoglobulin G/immunology , Immunoglobulin M/blood , Immunoglobulin M/immunology , Infant , Infant, Newborn , Male , Middle Aged
9.
Microbiol Spectr ; 9(2): e0141621, 2021 10 31.
Article in English | MEDLINE | ID: covidwho-1495015

ABSTRACT

The rapid worldwide spread of SARS-CoV-2 has accelerated research and development for controlling the COVID-19 pandemic. A multi-coronavirus protein microarray was created containing full-length proteins, overlapping protein fragments of various lengths, and peptide libraries from SARS-CoV-2 and four other human coronaviruses. Sera from confirmed COVID-19 patients as well as unexposed individuals were applied to multicoronavirus arrays to identify specific antibody reactivity. High-level IgG, IgM, and IgA reactivity to structural proteins S, M, and N of SARS-CoV-2, as well as accessory proteins such as ORF3a and ORF7a, were observed that were specific to COVID-19 patients. Antibody reactivity against overlapping 100-, 50-, and 30-amino acid fragments of SARS-CoV-2 proteins was used to identify antigenic regions. Numerous proteins of SARS-CoV, Middle East respiratory syndrome coronavirus (MERS-CoV), and the endemic human coronaviruses HCoV-NL63 and HCoV-OC43 were also more reactive with IgG, IgM, and IgA in COVID-19 patient sera than in unexposed control sera, providing further evidence of immunologic cross-reactivity between these viruses. Whereas unexposed individuals had minimal reactivity against SARS-CoV-2 proteins that poorly correlated with reactivity against HCoV-NL63 and HCoV-OC43 S2 and N proteins, COVID-19 patient sera had higher correlation between SARS-CoV-2 and HCoV responses, suggesting that de novo antibodies against SARS-CoV-2 cross-react with HCoV epitopes. Array responses were compared with validated spike protein-specific IgG enzyme-linked immunosorbent assays (ELISAs), showing agreement between orthologous methods. SARS-CoV-2 microneutralization titers were low in the COVID-19 patient sera but correlated with array responses against S and N proteins. The multi-coronavirus protein microarray is a useful tool for mapping antibody reactivity in COVID-19 patients. IMPORTANCE With novel mutant SARS-CoV-2 variants of concern on the rise, knowledge of immune specificities against SARS-CoV-2 proteins is increasingly important for understanding the impact of structural changes in antibody-reactive protein epitopes on naturally acquired and vaccine-induced immunity, as well as broader topics of cross-reactivity and viral evolution. A multi-coronavirus protein microarray used to map the binding of COVID-19 patient antibodies to SARS-CoV-2 proteins and protein fragments as well as to the proteins of four other coronaviruses that infect humans has shown specific regions of SARS-CoV-2 proteins that are highly reactive with patient antibodies and revealed cross-reactivity of these antibodies with other human coronaviruses. These data and the multi-coronavirus protein microarray tool will help guide further studies of the antibody response to COVID-19 and to vaccination against this worldwide pandemic.


Subject(s)
Antibodies, Viral/immunology , Coronavirus NL63, Human/immunology , Coronavirus OC43, Human/immunology , Epitopes/immunology , Middle East Respiratory Syndrome Coronavirus/immunology , SARS-CoV-2/immunology , Antibodies, Viral/blood , Binding Sites, Antibody/immunology , COVID-19/immunology , Coronavirus Nucleocapsid Proteins/immunology , Cross Reactions/immunology , Enzyme-Linked Immunosorbent Assay , Humans , Immunoglobulin A/immunology , Immunoglobulin G/immunology , Immunoglobulin M/immunology , Phosphoproteins/immunology , Protein Array Analysis , Spike Glycoprotein, Coronavirus/immunology , Viral Proteins/immunology , Viroporin Proteins/immunology
10.
Cells ; 10(10)2021 09 26.
Article in English | MEDLINE | ID: covidwho-1438527

ABSTRACT

Specific memory B cells and antibodies are a reliable read-out of vaccine efficacy. We analysed these biomarkers after one and two doses of BNT162b2 vaccine. The second dose significantly increases the level of highly specific memory B cells and antibodies. Two months after the second dose, specific antibody levels decline, but highly specific memory B cells continue to increase, thus predicting a sustained protection from COVID-19. We show that although mucosal IgA is not induced by the vaccination, memory B cells migrate in response to inflammation and secrete IgA at mucosal sites. We show that the first vaccine dose may lead to an insufficient number of highly specific memory B cells and low concentration of serum antibodies, thus leaving vaccinees without the immune robustness needed to ensure viral elimination and herd immunity. We also clarify that the reduction of serum antibodies does not diminish the force and duration of the immune protection induced by vaccination. The vaccine does not induce sterilizing immunity. Infection after vaccination may be caused by the lack of local preventive immunity because of the absence of mucosal IgA.


Subject(s)
Antibodies, Viral/immunology , B-Lymphocytes/cytology , COVID-19 Vaccines/therapeutic use , COVID-19/immunology , COVID-19/prevention & control , Immunoglobulin A/immunology , Immunologic Memory , Adult , Antibodies, Neutralizing/blood , Antigens, Viral/immunology , B-Lymphocytes/immunology , Cryopreservation , Female , Health Personnel , Healthy Volunteers , Hospitals, Pediatric , Humans , Immunoglobulin G , Immunoglobulin M/immunology , Lactation , Male , Middle Aged , Mucous Membrane/immunology , Patient Safety , SARS-CoV-2 , Vaccination
11.
Microbiol Spectr ; 9(2): e0059021, 2021 10 31.
Article in English | MEDLINE | ID: covidwho-1434909

ABSTRACT

To assess the persistence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies produced by natural infection and describe the serological characteristics over 7 months after symptom onset among coronavirus disease 2019 (COVID-19) patients by age and severity group, we followed up COVID-19 convalescent patients confirmed from 1 January to 20 March 2020 in Jiangsu, China and collected serum samples for testing IgM/IgG and neutralizing antibodies against SARS-CoV-2 between 26 August and 28 October 2020. In total, 284 recovered participants with COVID-19 were enrolled in our study. Patients had a mean age of 46.72 years (standard deviation [SD], 17.09), and 138 (48.59%) were male. The median follow-up time after symptom onset was 225.5 (interquartile range [IQR], 219 to 232) days. During the follow-up period (162 to 282 days after symptom onset), the seropositive rate of IgM fluctuated around 25.70% (95% confidence interval [CI], 20.72% to 31.20%) and that of IgG fluctuated around 79.93% (95% CI, 74.79% to 84.43%). Of the 284 patients, 64 participants were tested when discharged from hospital. Compared with that at the acute phase, the IgM/IgG antibody levels and IgM seropositivity have decreased; however, the seropositivity of IgG was not significantly lower at this follow-up (78.13% versus 82.81%). Fifty percent inhibitory dilution (ID50) titers of neutralizing antibody for samples when discharged from hospital (geometric mean titer [GMT], 82; 95% CI, 56 to 121) were significantly higher than those at 6 to 7 months after discharge (GMT, 47; 95% CI, 35 to 63) (P < 0.001). After 7 months from symptom onset, the convalescent COVID-19 patients continued to have high IgG seropositive; however, many plasma samples decreased neutralizing activity. IMPORTANCE The long-term characteristics of anti-SARS-CoV-2 antibodies among COVID-19 patients remain largely unclear. Tracking the longevity of these antibodies can provide a forward-looking reference for monitoring COVID-19. We conducted a comprehensive assessment combining the kinetics of specific and neutralizing antibodies over 7 months with age and disease severity and revealed influencing factors of the protection period of convalescent patients. By observing the long-term antibody levels against SARS-CoV-2 and comparing antibody levels at two time points after symptom onset, we found that the convalescent COVID-19 patients continued to have a high IgG seropositive rate; however, their plasma samples decreased neutralizing activity. These findings provide evidence supporting that the neutralizing activity of SARS-CoV-2-infected persons should be monitored and the administration of vaccine may be needed.


Subject(s)
Antibodies, Neutralizing/blood , Antibodies, Viral/blood , Immunoglobulin G/blood , Immunoglobulin M/blood , SARS-CoV-2/immunology , Adolescent , Adult , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , COVID-19/immunology , Child , Female , Humans , Immunoglobulin G/immunology , Immunoglobulin M/immunology , Immunologic Memory/immunology , Male , Middle Aged , Young Adult
12.
PLoS One ; 16(9): e0253090, 2021.
Article in English | MEDLINE | ID: covidwho-1430522

ABSTRACT

BACKGROUND: Background Population-based data on SARS-CoV-2 infection in pregnancy and assessment of passive immunity to the neonate, is lacking. We profiled the maternal and fetal response using a combination of viral RNA from naso-pharyngeal swabs and serological assessment of antibodies against SARS-CoV-2. METHODS: This multicentre prospective observational study was conducted between March 24th and August 31st 2020. Two independent cohorts were established, a symptomatic SARS-CoV-2 cohort and a cohort of asymptomatic pregnant women attending two of the largest maternity hospitals in Europe. Symptomatic women were invited to provide a serum sample to assess antibody responses. Asymptomatic pregnant women provided a nasopharyngeal swab and serum sample. RT-PCR for viral RNA was performed using the Cobas SARS-CoV-2 6800 platform (Roche). Umbilical cord bloods were obtained at delivery. Maternal and fetal serological response was measured using both the Elecsys® Anti-SARS-CoV-2 immunoassay (Roche), Abbott SARS-CoV-2 IgG Assay and the IgM Architect assay. Informed written consent was obtained from all participants. RESULTS: Ten of twenty three symptomatic women had SARS-CoV-2 RNA detected on nasopharyngeal swabs. Five (5/23, 21.7%) demonstrated serological evidence of anti-SARS-CoV-2 IgG antibodies and seven (30.4%, 7/23) were positive for IgM antibodies. In the asymptomatic cohort, the prevalence of SARS-CoV-2 infection in RNA was 0.16% (1/608). IgG SARS-CoV-2 antibodies were detected in 1·67% (10/598, 95% CI 0·8%-3·1%) and IgM in 3·51% (21/598, 95% CI 2·3-5·5%). Nine women had repeat testing post the baseline test. Four (4/9, 44%) remained IgM positive and one remained IgG positive. 3 IgG anti-SARS-CoV-2 antibodies were detectable in cord bloods from babies born to five seropositive women who delivered during the study. The mean gestation at serological test was 34 weeks. The mean time between maternal serologic positivity and detection in umbilical cord samples was 28 days. CONCLUSION: Using two independent serological assays, we present a comprehensive illustration of the antibody response to SARS-CoV-2 in pregnancy, and show a low prevalence of asymptomatic SARS-CoV2. Transplacental migration of anti-SARS-CoV-2 antibodies was identified in cord blood of women who demonstrated antenatal anti-SARS-CoV-2 antibodies, raising the possibility of passive immunity.


Subject(s)
COVID-19/diagnosis , COVID-19/immunology , Delivery, Obstetric , SARS-CoV-2/immunology , Antibody Formation/immunology , COVID-19/genetics , COVID-19/virology , Female , Fetal Blood/metabolism , Follow-Up Studies , Humans , Immunoglobulin G/immunology , Immunoglobulin M/immunology , Longitudinal Studies , Pregnancy , Prospective Studies
13.
PLoS One ; 16(9): e0255498, 2021.
Article in English | MEDLINE | ID: covidwho-1410655

ABSTRACT

BACKGROUND: Overcrowded housing, as well as inadequate sanitary conditions, contribute to making homeless people particularly vulnerable to the SARS-CoV-2 infection. We aimed to assess the seroprevalence of the SARS-CoV-2 infection among people experiencing homelessness on a large city-wide scale in Marseille, France, taking into account different types of accommodation. METHODS: A consortium of outreach teams in 48 different locations including streets, slums, squats, emergency or transitional shelters and drop-in centres participated in the inclusion process. All participants consented to have a validated rapid antibody assay for immunoglobulins M (IgM) and G (IgG) and to answer a questionnaire on medical health conditions, comorbidities, and previous COVID-19 symptoms. Information on their housing conditions since the COVID-19 crisis was also collected from the participants. RESULTS: From June 01 to August 05, 2020, 1,156 homeless participants were enrolled in the study and tested. The overall seroprevalence of SARS-CoV-2 IgG/IgM antibodies was 5.6% (95%CI 2.3-7.0), ranging from 2.2% in people living on the streets to 8.1% in people living in emergency shelters (P = 0.009). Around one third of the seropositive participants reported COVID-19 symptoms. Compared to the general population in Marseille (3.6%), the homeless population living in the same urban area experienced a significantly increased risk of SARS-CoV-2 infection (|z| = 3.65 > 1.96). CONCLUSION: These findings highlight the need for regular screening among the homeless to prevent clustering in overcrowded or inadequate accommodations. It is also necessary to provide essential resources to keep homeless people healthy, the vast majority of whom have cumulative risk factors for SARS-CoV-2 infection.


Subject(s)
Antibodies, Viral/immunology , COVID-19/diagnosis , Homeless Persons/statistics & numerical data , Housing/statistics & numerical data , SARS-CoV-2/immunology , Surveys and Questionnaires/statistics & numerical data , Adult , Aged , Antibodies, Viral/blood , COVID-19/epidemiology , COVID-19/virology , Cross-Sectional Studies , Epidemics/prevention & control , Female , France/epidemiology , Geography , Housing/standards , Humans , Immunoglobulin G/blood , Immunoglobulin G/immunology , Immunoglobulin M/blood , Immunoglobulin M/immunology , Male , Middle Aged , Population Surveillance/methods , SARS-CoV-2/physiology , Seroepidemiologic Studies
14.
Front Immunol ; 12: 724763, 2021.
Article in English | MEDLINE | ID: covidwho-1399141

ABSTRACT

Characterizing the serologic features of asymptomatic SARS-CoV-2 infection is imperative to improve diagnostics and control of SARS-CoV-2 transmission. In this study, we evaluated the antibody profiles in 272 plasma samples collected from 59 COVID-19 patients, consisting of 18 asymptomatic patients, 33 mildly ill patients and 8 severely ill patients. We measured the IgG against five viral structural proteins, different isotypes of immunoglobulins against the Receptor Binding Domain (RBD) protein, and neutralizing antibodies. The results showed that the overall antibody response was lower in asymptomatic infections than in symptomatic infections throughout the disease course. In contrast to symptomatic patients, asymptomatic patients showed a dominant IgG-response towards the RBD protein, but not IgM and IgA. Neutralizing antibody titers had linear correlations with IgA/IgM/IgG levels against SARS-CoV-2-RBD, as well as with IgG levels against multiple SARS-CoV-2 structural proteins, especially with anti-RBD or anti-S2 IgG. In addition, the sensitivity of anti-S2-IgG is better in identifying asymptomatic infections at early time post infection compared to anti-RBD-IgG. These data suggest that asymptomatic infections elicit weaker antibody responses, and primarily induce IgG antibody responses rather than IgA or IgM antibody responses. Detection of IgG against the S2 protein could supplement nucleic acid testing to identify asymptomatic patients. This study provides an antibody detection scheme for asymptomatic infections, which may contribute to epidemic prevention and control.


Subject(s)
Antibodies, Viral/blood , Asymptomatic Infections , Immunoglobulin G/blood , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/immunology , Viral Structural Proteins/immunology , Adolescent , Adult , Antibodies, Neutralizing/immunology , Antibodies, Viral/physiology , Binding Sites, Antibody , Female , Humans , Immunoglobulin G/classification , Immunoglobulin M/immunology , Kinetics , Male , Middle Aged , Neutralization Tests/statistics & numerical data , SARS-CoV-2/chemistry , Young Adult
15.
Front Immunol ; 12: 722027, 2021.
Article in English | MEDLINE | ID: covidwho-1399138

ABSTRACT

Approximately half of the SARS-CoV-2 infections occur without apparent symptoms, raising questions regarding long-term humoral immunity in asymptomatic individuals. Plasma levels of immunoglobulin G (IgG) and M (IgM) against the viral spike or nucleoprotein were determined for 25,091 individuals enrolled in a surveillance program in Wuhan, China. We compared 405 asymptomatic individuals who mounted a detectable antibody response with 459 symptomatic COVID-19 patients. The well-defined duration of the SARS-CoV-2 endemic in Wuhan allowed a side-by-side comparison of antibody responses following symptomatic and asymptomatic infections without subsequent antigen re-exposure. IgM responses rapidly declined in both groups. However, both the prevalence and durability of IgG responses and neutralizing capacities correlated positively with symptoms. Regardless of sex, age, and body weight, asymptomatic individuals lost their SARS-CoV-2-specific IgG antibodies more often and rapidly than symptomatic patients did. These findings have important implications for immunity and favour immunization programs including individuals after asymptomatic infections.


Subject(s)
Antibodies, Viral/blood , Asymptomatic Infections/epidemiology , COVID-19/immunology , Immunity, Humoral , SARS-CoV-2/immunology , Adult , Antibodies, Neutralizing/immunology , Antibody Formation , COVID-19/epidemiology , China , Epidemiological Monitoring , Female , Humans , Immunoglobulin G/immunology , Immunoglobulin M/immunology , Male , Middle Aged , Retrospective Studies , SARS-CoV-2/pathogenicity , Young Adult
16.
PLoS One ; 16(9): e0248444, 2021.
Article in English | MEDLINE | ID: covidwho-1394535

ABSTRACT

The pandemic of novel coronavirus disease COVID-19 is rapidly expanding across the world. A positive result of antibody tests suggests that the individual has potentially been exposed to SARS-CoV-2, thus allowing to identify asymptomatic infections and determine the seroprevalence in a given population. The aim of this study was to evaluate the performances of a newly developed high throughput immunoassay for anti-SARS-CoV-2 IgM antibody detection on the Luminex MAGPIX platform. Clinical agreement studies were performed in 42 COVID-19 patient serum samples and 162 negative donor serum/plasma samples. Positive percent agreement (PPA) was 42.86% (95% CI: 9.90% to 81.59%), 71.43% (95% CI: 29.04% to 96.33%), and 28.57% (95% CI: 13.22% to 48.67%) for samples collected on 0-7 days, 8-14 days, and 2-8 weeks from symptom onset, respectively. Negative Percent Agreement (NPA) was 97.53% (95% CI: 93.80% to 99.32%). There was no cross-reactivity with the SARS-CoV-2 IgG antibody. Hemoglobin (200 mg/dL), bilirubin (2 mg/dL), triglyceride (250 mg/dL) and EDTA (10 mM) showed no significant interfering effect on this assay. In conclusion, an anti-SARS-CoV-2 IgM antibody assay with high sensitivity and specificity has been developed. With the high throughput, this assay will speed up the anti-SARS-CoV-2 IgM testing.


Subject(s)
Antibodies, Viral/immunology , COVID-19 Serological Testing/methods , Immunoassay/methods , Immunoglobulin M/immunology , Microspheres , SARS-CoV-2/immunology , Antibodies, Viral/blood , High-Throughput Screening Assays/methods , Humans , Immunoglobulin G/blood , Immunoglobulin G/immunology , Immunoglobulin M/blood , ROC Curve , SARS-CoV-2/physiology
17.
PLoS Pathog ; 17(1): e1009161, 2021 01.
Article in English | MEDLINE | ID: covidwho-1388959

ABSTRACT

We report the emergency development and application of a robust serologic test to evaluate acute and convalescent antibody responses to SARS-CoV-2 in Argentina. The assays, COVIDAR IgG and IgM, which were produced and provided for free to health authorities, private and public health institutions and nursing homes, use a combination of a trimer stabilized spike protein and the receptor binding domain (RBD) in a single enzyme-linked immunosorbent assay (ELISA) plate. Over half million tests have already been distributed to detect and quantify antibodies for multiple purposes, including assessment of immune responses in hospitalized patients and large seroprevalence studies in neighborhoods, slums and health care workers, which resulted in a powerful tool for asymptomatic detection and policy making in the country. Analysis of antibody levels and longitudinal studies of symptomatic and asymptomatic SARS-CoV-2 infections in over one thousand patient samples provided insightful information about IgM and IgG seroconversion time and kinetics, and IgM waning profiles. At least 35% of patients showed seroconversion within 7 days, and 95% within 45 days of symptoms onset, with simultaneous or close sequential IgM and IgG detection. Longitudinal studies of asymptomatic cases showed a wide range of antibody responses with median levels below those observed in symptomatic patients. Regarding convalescent plasma applications, a protocol was standardized for the assessment of end point IgG antibody titers with COVIDAR with more than 500 plasma donors. The protocol showed a positive correlation with neutralizing antibody titers, and was used for clinical trials and therapies across the country. Using this protocol, about 80% of convalescent donor plasmas were potentially suitable for therapies. Here, we demonstrate the importance of providing a robust and specific serologic assay for generating new information about antibody kinetics in infected individuals and mitigation policies to cope with pandemic needs.


Subject(s)
COVID-19/virology , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/immunology , Adult , Aged , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , Antibody Formation , Argentina/epidemiology , COVID-19/epidemiology , Enzyme-Linked Immunosorbent Assay/methods , Female , Humans , Immunoglobulin G/immunology , Immunoglobulin M/immunology , Longitudinal Studies , Male , Middle Aged , Pandemics , SARS-CoV-2/isolation & purification , Seroepidemiologic Studies
19.
Front Immunol ; 11: 932, 2020.
Article in English | MEDLINE | ID: covidwho-1389160

ABSTRACT

While studying the human public IgM igome as represented by a library of 224,087 linear mimotopes, three exact matches to peptides in the proteins of SARS-CoV-2 were found: two in the open reading frame 1ab and one in the spike protein. Joining the efforts to fast track SARS-CoV-2 vaccine development, here we describe briefly these potential epitopes in comparison to mimotopes representing peptides of SARS-CoV, HCoV 229E and OC43.


Subject(s)
Antibodies, Viral/immunology , Betacoronavirus/immunology , Epitopes/chemistry , Immunoglobulin M/immunology , Antibodies, Viral/chemistry , Humans , Immunoglobulin M/chemistry , Peptides/chemistry , Peptides/immunology , SARS-CoV-2 , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/immunology
20.
Jpn J Infect Dis ; 74(4): 333-336, 2021 Jul 21.
Article in English | MEDLINE | ID: covidwho-1380102

ABSTRACT

This study aimed to evaluate the infection rate of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) among different populations in Wuhan, China. This cross-sectional survey-based study examined the results of SARS-CoV-2-specific serological tests and RT-PCR tests for 4,454 community residents and 4,614 healthcare workers performed from May 15 to May 29, 2020. The healthcare workers were classified as administrative and logistical staff (n = 1,378), non-first-line healthcare workers (n = 2,630), or first-line healthcare workers (n = 606) according to their frequency of contact with coronavirus disease (COVID-19) patients. The positive rates of SARS-CoV-2-specific IgG, IgM, and RNA were 2.9%, 0.4%, and 0.1% for the community residents and 3.3%, 0.6%, and 0.2% for the healthcare workers, respectively. There were no statistically significant differences between the rates of the two groups. Spearman's correlation analysis showed that the frequency of contact with COVID-19 patients negatively correlated with the positive rates of RT-PCR (rs = -0.036, P = 0.016), but did not significantly correlate with the positive rates of IgM (rs = -0.006, P = 0.698) or IgG (rs = 0.017, P = 0.239). There was no statistically significant difference between the SARS-CoV-2-specific IgG, IgM, or RNA positive rates of the community residents and those of the healthcare workers. The positive rate of SARS-CoV-2 RNA was lower for the first-line healthcare workers than for the non-first-line healthcare workers and the administrative and logistical staff.


Subject(s)
COVID-19/blood , COVID-19/immunology , Adult , Antibodies, Viral/blood , Antibodies, Viral/immunology , COVID-19/virology , COVID-19 Testing/methods , China , Cross-Sectional Studies , Female , Health Personnel , Humans , Immunoglobulin G/blood , Immunoglobulin G/immunology , Immunoglobulin M/blood , Immunoglobulin M/immunology , Male , RNA, Viral/genetics , Reverse Transcriptase Polymerase Chain Reaction/methods , SARS-CoV-2/genetics , SARS-CoV-2/immunology , Serology/methods
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