Serum levels of anti-corona virus specific -IgG and -IgM antibodies in COVID-19 patients at admission and at discharge

Introduction. Clear understanding of duration of antibody based protective immunity following natural infection with SARSCoV- 2 will give idea about the efficacy of proposed prophylactic vaccines against SARS-CoV-2, establishment of herd immunity and use of convalescent plasma. Aim. This study clarified the kinetics and magnitude of the initial antibody response against SARS-CoV-2 in a cohort of symptomatic COVID-19 patients from Ibadan, Nigeria. Material and methods. This study quantified immunoglobulin M (IgM) and G (IgG) antibodies recognizing the SARS-CoV-2 Spike (S) protein in 35 symptomatic COVID-19 patients at admission and at discharge using ELISA. Results. CovIgG was positive in none (0)% and 20% of COVID-19 patients at admission and at discharge respectively while CovIgM was positive in 54% and 69% of COVID-19 patients at admission and at discharged respectively. The level of CovIgG was significantly higher in COVID-19 patients at discharge compared with the level at admission while the level of CovIgM was insignificantly reduced in COVID-19 patients at discharge compared with the level at admission. Conclusion. The data indicates increased anti-SARS-COV-2 IgG Spike antibody in symptomatic COVID-19 at discharge, thus providing basis for antibody-based therapies to treat COVID-19 patients.

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Endogenously Produced SARS-CoV-2 Specific IgG Antibodies May Have a Limited Impact on Clearing Nasal Shedding of Virus during Primary Infection in Humans

Viruses ◽

10.3390/v13030516 ◽

2021 ◽

Vol 13 (3) ◽

pp. 516

Author(s):

Shuyi Yang ◽

Keith R. Jerome ◽

Alexander L. Greninger ◽

Joshua T. Schiffer ◽

Ashish Goyal

Keyword(s):

Production Rate ◽

Neutralizing Antibodies ◽

Primary Infection ◽

Natural Infection ◽

Viral Clearance ◽

Clinical Severity ◽

Igg Antibodies ◽

Igm Antibodies ◽

Specific Igg ◽

Specific Igg Antibodies

While SARS-CoV-2 specific neutralizing antibodies have been developed for therapeutic purposes, the specific viral triggers that drive the generation of SARS-CoV-2 specific IgG and IgM antibodies remain only partially characterized. Moreover, it is unknown whether endogenously derived antibodies drive viral clearance that might result in mitigation of clinical severity during natural infection. We developed a series of non-linear mathematical models to investigate whether SARS-CoV-2 viral and antibody kinetics are coupled or governed by separate processes. Patients with severe disease had a higher production rate of IgG but not IgM antibodies. Maximal levels of both isotypes were governed by their production rate rather than different saturation levels between people. Our results suggest that an exponential surge in IgG levels occurs approximately 5–10 days after symptom onset with no requirement for continual antigenic stimulation. SARS-CoV-2 specific IgG antibodies appear to have limited to no effect on viral dynamics but may enhance viral clearance late during primary infection resulting from the binding effect of antibody to virus, rather than neutralization. In conclusion, SARS-CoV-2 specific IgG antibodies may play only a limited role in clearing infection from the nasal passages despite providing long-term immunity against infection following vaccination or prior infection.

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Declining Levels of Neutralizing Antibodies Against SARS-CoV-2 in Convalescent COVID-19 Patients One Year Post Symptom Onset

Frontiers in Immunology ◽

10.3389/fimmu.2021.708523 ◽

2021 ◽

Vol 12 ◽

Author(s):

Tiandan Xiang ◽

Boyun Liang ◽

Yaohui Fang ◽

Sihong Lu ◽

Sumeng Li ◽

...

Keyword(s):

Symptom Onset ◽

Neutralizing Antibodies ◽

Natural Infection ◽

Protein S ◽

Igg Antibodies ◽

Neutralizing Activity ◽

Specific Igg ◽

One Year ◽

Kinetics Of

Major advances have been made in understanding the dynamics of humoral immunity briefly after the acute coronavirus disease 2019 (COVID-19). However, knowledge concerning long-term kinetics of antibody responses in convalescent patients is limited. During a one-year period post symptom onset, we longitudinally collected 162 samples from 76 patients and quantified IgM and IgG antibodies recognizing the nucleocapsid (N) protein or the receptor binding domain (RBD) of the spike protein (S). After one year, approximately 90% of recovered patients still had detectable SARS-CoV-2-specific IgG antibodies recognizing N and RBD-S. Intriguingly, neutralizing activity was only detectable in ~43% of patients. When neutralization tests against the E484K-mutated variant of concern (VOC) B.1.351 (initially identified in South Africa) were performed among patients who neutralize the original virus, the capacity to neutralize was even further diminished to 22.6% of donors. Despite declining N- and S-specific IgG titers, a considerable fraction of recovered patients had detectable neutralizing activity one year after infection. However, neutralizing capacities, in particular against an E484K-mutated VOC were only detectable in a minority of patients one year after symptomatic COVID-19. Our findings shed light on the kinetics of long-term immune responses after natural SARS-CoV-2 infection and argue for vaccinations of individuals who experienced a natural infection to protect against emerging VOC.

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SEROPREVALENCE OF ANTI-MEASLES IGG IN THE POPULATION OF KHARKIV REGION IN 2018-2019

Immunology and Allergy: Science and Practice ◽

10.37321/immunology.2019.04-03 ◽

2019 ◽

pp. 22-25

Author(s):

Igor Yudin ◽

Irina Kuchma ◽

Andriy Voliansky

Keyword(s):

Herd Immunity ◽

Age Groups ◽

Igg Antibodies ◽

Prevention Strategies ◽

Elisa Method ◽

Negative Results ◽

Specific Igg ◽

Susceptible Populations ◽

Vaccination Campaigns ◽

Specific Igg Antibodies

Aim. The aim of this study was to evaluate herd immunity against measles in different age groups of the Kharkiv region of Ukraine’s population. Materials and methods. Seroprevalence of specific IgG antibodies was studied among different age groups of the Kharkiv region population from February 2018 to July 2019 by ELISA method. Results. A number of 6564 sera samples were processed. The overall seropositivity level was 91.3%; negative results were 5.3% and 3.3% equivocal. The highest seropositivity for IgG (> 98%) was in people aged 50 years and older. The lowest seropositivity rates were observed in the cohorts of 20-29 years (87.2%), 30-39 years (86.9%), and 40-49 years (91.1%). Conclusions. Measles-susceptible populations were identified for which new prevention strategies should be applied in the form of personalized vaccination campaigns to increase herd immunity.

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Profiles of Immunoglobulin M (IgM) and IgG Antibodies against Defined Carbohydrate Epitopes in Sera of Schistosoma-Infected Individuals Determined by Surface Plasmon Resonance

Infection and Immunity ◽

10.1128/iai.69.4.2396-2401.2001 ◽

2001 ◽

Vol 69 (4) ◽

pp. 2396-2401 ◽

Cited By ~ 53

Author(s):

Alexandra van Remoortere ◽

Govert J. van Dam ◽

Cornelis H. Hokke ◽

Dirk H. van den Eijnden ◽

Irma van Die ◽

...

Keyword(s):

Immune Response ◽

Surface Plasmon Resonance ◽

Surface Plasmon ◽

Plasmon Resonance ◽

Serum Levels ◽

Immunoglobulin M ◽

Igg Subclass ◽

Igg Antibodies ◽

Humoral Immune ◽

Carbohydrate Epitopes

ABSTRACT We report here that sera of children and adults infected withSchistosoma mansoni, S. haematobium, or S. japonicum contain antibodies against GalNAcβ1-4(Fucα1-2Fucα1-3)GlcNAc (LDN-DF) and to a lesser extent to Galβ1-4(Fucα1-3)GlcNAc (Lewisx) and GalNAcβ1-4GlcNAc (LDN). Surface plasmon resonance (SPR) spectroscopy was used to monitor the presence of serum antibodies to neoglycoconjugates containing these carbohydrate epitopes and to define the immunoglobulin M (IgM) and IgG subclass distribution of the antibodies. The serum levels of antibodies to LDN-DF are high related to LDN and Lewisx for all examined groups ofSchistosoma-infected individuals. A higher antibody response to the LDN-DF epitope was found in sera of infected children than in sera of infected adults regardless of the schistosome species. With respect to the subclasses, we found surprisingly that individuals infected with S. japonicum have predominantly IgG antibodies, while individuals infected with S. mansonimainly show an IgM response; high levels of both isotypes were measured in sera of individuals infected with S. haematobium. These data provide new insights in the human humoral immune response to schistosome-derived glycans.

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Protective Immunity Induced by an Eimeria tenella Whole Sporozoite Vaccine Elicits Specific B-Cell Antigens

Animals ◽

10.3390/ani11051344 ◽

2021 ◽

Vol 11 (5) ◽

pp. 1344

Author(s):

Marco A. Juárez-Estrada ◽

Amanda Gayosso-Vázquez ◽

Guillermo Tellez-Isaias ◽

Rogelio A. Alonso-Morales

Keyword(s):

B Cell ◽

Protective Immunity ◽

Animal Species ◽

Eimeria Tenella ◽

Igg Antibodies ◽

Recognition Pattern ◽

Life Cycle Stages ◽

Specific Pathogen ◽

Specific Igg ◽

Specific Igg Antibodies

This study investigated protection against Eimeria tenella following the vaccination of chicks with 5.3 × 106 E. tenella whole-sporozoites emulsified in the nanoparticle adjuvant IMS 1313 N VG Montanide™ (EtSz-IMS1313). One-day-old specific pathogen-free (SPF) chicks were subcutaneously injected in the neck with EtSz-IMS1313 on the 1st and 10th days of age. Acquired immunity was assayed through a challenge with 3 × 104 homologous sporulated oocysts at 21 days of age. The anticoccidial index (ACI) calculated for every group showed the effectiveness of EtSz-IMS1313 as a vaccine with an ACI of 186; the mock-injected control showed an ACI of 18 and the unimmunized, challenged control showed an ACI of −28. In a comparison assay, antibodies from rabbits and SPF birds immunized with EtSz-IMS1313 recognized almost the same polypeptides in the blotting of E. tenella sporozoites and merozoites. However, rabbit antisera showed the clearest recognition pattern. Polypeptides of 120, 105, 94, 70, 38, and 19 kDa from both E. tenella life cycle stages were the most strongly recognized by both animal species. The E. tenella zoite-specific IgG antibodies from the rabbits demonstrated the feasibility for successful B cell antigen identification.

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Influence of obesity on serum levels of SARS-CoV-2-specific antibodies in COVID-19 patients

PLoS ONE ◽

10.1371/journal.pone.0245424 ◽

2021 ◽

Vol 16 (3) ◽

pp. e0245424

Author(s):

Daniela Frasca ◽

Lisa Reidy ◽

Carolyn Cray ◽

Alain Diaz ◽

Maria Romero ◽

...

Keyword(s):

Humoral Immunity ◽

Serum Levels ◽

Obese Patients ◽

Igg Antibodies ◽

Nonesterified Fatty Acids ◽

Negatively Associated ◽

Amyloid A ◽

Serum Amyloid A Protein ◽

Specific Igg ◽

Specific Igg Antibodies

SARS-CoV-2 (Severe Acute Respiratory Syndrome Corona Virus-2), cause of COVID-19 (Coronavirus Disease of 2019), represents a significant risk to people living with pre-existing conditions associated with exacerbated inflammatory responses and consequent dysfunctional immunity. In this paper, we have evaluated the influence of obesity, a condition associated with chronic systemic inflammation, on the secretion of SARS-CoV-2-specific IgG antibodies in the blood of COVID-19 patients. Our hypothesis is that obesity is associated with reduced amounts of specific IgG antibodies. Results have confirmed our hypothesis and have shown that SARS-CoV-2 IgG antibodies are negatively associated with Body Mass Index (BMI) in COVID-19 obese patients, as expected based on the known influence of obesity on humoral immunity. Antibodies in COVID-19 obese patients are also negatively associated with serum levels of pro-inflammatory and metabolic markers of inflammaging and pulmonary inflammation, such as SAA (serum amyloid A protein), CRP (C-reactive protein), and ferritin, but positively associated with NEFA (nonesterified fatty acids). These results altogether could help to identify an inflammatory signature with strong predictive value for immune dysfunction. Inflammatory markers identified may subsequently be targeted to improve humoral immunity in individuals with obesity and in individuals with other chronic inflammatory conditions.

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The risk of symptomatic reinfection during the second COVID-19 wave in individuals previously exposed to SARS-CoV-2

10.1101/2021.04.14.21255502 ◽

2021 ◽

Author(s):

Mattia Manica ◽

Serena Pancheri ◽

Piero Poletti ◽

Giulia Giovanazzi ◽

Giorgio Guzzetta ◽

...

Keyword(s):

Cohort Study ◽

Cumulative Incidence ◽

Protective Immunity ◽

Natural Infection ◽

Entire Population ◽

Serological Response ◽

Igg Antibodies ◽

Symptomatic Infection

To what extent infection with SARS-CoV-2 protects against subsequent reinfection or symptomatic reinfection is still unclear. In this cohort study, we analyzed surveillance records of COVID-19 cases identified between June 2020 and January 2021 in five Italian municipalities, where 77.7% of the entire population was screened for IgG antibodies in May 2020. We compared the risk of observing symptomatic infections in two mutually exclusive groups defined by the initial serological response. We estimated that the cumulative incidence of identified symptomatic infections in the IgG negative and positive cohorts was 2.67% (95%CI: 2.12%-3.37%) and 0.14% (95%CI: 0.04%-0.58%), respectively. The adjusted odd ratio of developing symptomatic infection in individuals previously exposed to SARS-CoV-2 was estimated at 0.054 (95%CI: 0.009-0.169). Quantifying protective immunity against COVID-19 disease elicited by natural infection with SARS-CoV-2 is essential to inform strategies for controlling the pandemic in the forthcoming months.

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Adaptive immune responses to SARS-CoV-2 in recovered severe COVID-19 patients

10.1101/2021.01.05.20249027 ◽

2021 ◽

Author(s):

Beatriz Olea ◽

Eliseo Albert ◽

Ignacio Torres ◽

Paula Amat ◽

María José Remigia ◽

...

Keyword(s):

T Cells ◽

Serum Levels ◽

Igg Antibodies ◽

Cell Responses ◽

Adaptive Immune ◽

Specific Serum ◽

M Proteins ◽

Specific Igg ◽

Ifn Γ ◽

Over Time

ABSTRACTObjectivesThere is an imperative need to determine the durability of adaptive immunity to SARS-CoV-2. We enumerated SARS-CoV-2-reactive CD4+ and CD8+ T cells targeting S1 and M proteins and measured RBD-specific serum IgG over a period of 2-6 months after symptoms onset in a cohort of subjects who had recovered from severe clinical forms of COVID-19.MethodsWe recruited 58 patients (38 males and 20 females; median age, 62.5 years), who had been hospitalized with bilateral pneumonia, 60% with one or more comorbidities. IgG antibodies binding to SARS-CoV-2 RBD were measured by ELISA. SARS-CoV-2-reactive CD69+-expressing-IFNγ-producing-CD4+ and CD8+ T cells were enumerated in heparinized whole blood by flow cytometry for ICS.ResultsDetectable SARS-CoV-2-S1/M-reactive CD69+-IFN-γ CD4+ and CD8+ T cells were displayed in 17 (29.3%) and 6 (10.3%) subjects respectively, at a median of 84 days after onset of symptoms (range, 58-191 days). Concurrent comorbidities increased the risk (OR, 3.15; 95% CI, 1.03-9.61; P=0.04) of undetectable T-cell responses in models adjusted for age, sex and hospitalization ward. Twenty-one out of the 35 patients (60%) had detectable RBD-specific serum IgGs at a median of 118 days (range, 60 to 145 days) after symptoms onset. SARS-CoV-2 RBD-specific IgG serum levels were found to drop significantly over time.ConclusionA relatively limited number of subjects who developed severe forms of COVID-19 had detectable SARS-CoV-2-S1/M IFNγ CD4+ and CD8+ T cells at midterm after clinical diagnosis. Our data also indicated that serum levels of RBD-specific IgGs decline over time, becoming undetectable in some patients.

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Incidence of COVID-19 reinfection among Midwestern healthcare employees

PLoS ONE ◽

10.1371/journal.pone.0262164 ◽

2022 ◽

Vol 17 (1) ◽

pp. e0262164

Author(s):

Anne Rivelli ◽

Veronica Fitzpatrick ◽

Christopher Blair ◽

Kenneth Copeland ◽

Jon Richards

Keyword(s):

Incidence Rate ◽

Protective Immunity ◽

Healthcare Workers ◽

Natural Infection ◽

Herd Immunity ◽

Primary Objective ◽

Observational Cohort ◽

Frequent Exposure ◽

Prior Infection ◽

Healthcare Employees

Given the overwhelming worldwide rate of infection and the disappointing pace of vaccination, addressing reinfection is critical. Understanding reinfection, including longevity after natural infection, will allow us to better know the prospect of herd immunity, which hinges on the assumption that natural infection generates sufficient, protective immunity. The primary objective of this observational cohort study is to establish the incidence of reinfection of COVID-19 among healthcare employees who experienced a prior COVID-19 infection over a 10-month period. Of 2,625 participants who experienced at least one COVID-19 infection during the 10-month study period, 156 (5.94%) experienced reinfection and 540 (20.57%) experienced recurrence after prior infection. Median days were 126.50 (105.50–171.00) to reinfection and 31.50 (10.00–72.00) to recurrence. Incidence rate of COVID-19 reinfection was 0.35 cases per 1,000 person-days, with participants working in COVID-clinical and clinical units experiencing 3.77 and 3.57 times, respectively, greater risk of reinfection relative to those working in non-clinical units. Incidence rate of COVID-19 recurrence was 1.47 cases per 1,000 person-days. This study supports the consensus that COVID-19 reinfection, defined as subsequent infection ≥ 90 days after prior infection, is rare, even among a sample of healthcare workers with frequent exposure.

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Development and Optimization of In-house ELISA for Detection of Human IgG Antibody to SARS-CoV-2 Full Length Spike Protein

Pathogens ◽

10.3390/pathogens9100803 ◽

2020 ◽

Vol 9 (10) ◽

pp. 803 ◽

Cited By ~ 2

Author(s):

Thamir A. Alandijany ◽

Sherif A. El-Kafrawy ◽

Ahmed M. Tolah ◽

Sayed S. Sohrab ◽

Arwa A. Faizo ◽

...

Keyword(s):

Protective Immunity ◽

Full Length ◽

The Novel ◽

Igg Antibodies ◽

Igg Antibody ◽

Human Coronavirus ◽

Human Igg ◽

Reliable Detection ◽

Human Sera ◽

Specific Igg

The ongoing coronavirus disease 19 (COVID-19) pandemic, caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), poses a threat to human health. Despite this, many affected countries are now in the process of gradual lifting of COVID-19 restrictions that were initially implemented in response to the pandemic. The success of the so-called “exit strategy” requires continued surveillance of virus circulation in the community and evaluation of the prevalence of protective immunity among population. Serology tests are valuable tools for these purposes. Herein, SARS-CoV-2 full-length spike (S) recombinant protein was utilized to develop and optimize an indirect enzyme-linked immunoassay (ELISA) that enables a reliable detection of virus-specific IgG antibody in human sera. Importantly, the performance of this assay was evaluated utilizing micro-neutralization (MN) assay as a reference test. Our developed ELISA offers 100% sensitivity, 98.4% specificity, 98.8% agreement, and high overall accuracy. Moreover, the optical density (OD) values of positive samples significantly correlated with their MN titers. The assay specifically detects human IgG antibodies directed against SARS-CoV-2, but not those to Middle East respiratory syndrome coronavirus (MERS-CoV) or human coronavirus HKU1 (HCoV-HKU1). The availability of this in-house ELISA protocol would be valuable for various diagnostic and epidemiological applications.

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