scholarly journals Clinical validation of the Siemens quantitative SARS-CoV-2 spike IgG assay (sCOVG) reveals improved sensitivity and a good correlation with virus neutralization titers

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Christian Irsara ◽  
Alexander E. Egger ◽  
Wolfgang Prokop ◽  
Manfred Nairz ◽  
Lorin Loacker ◽  
...  
Keyword(s):  
Immune Response ◽  
Clinical Performance ◽  
General Ward ◽  
Virus Neutralization ◽  
Clinical Validation ◽  
Receptor Binding Domain ◽  
Specific Antibody Response ◽  
Neutralization Capacity ◽  
Humoral Immune ◽  
Antibody Levels

Abstract Objectives Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections cause coronavirus disease 2019 (COVID-19) and induce a specific antibody response. Serological assays detecting IgG against the receptor binding domain (RBD) of the spike (S) protein are useful to monitor the immune response after infection or vaccination. The objective of our study was to evaluate the clinical performance of the Siemens SARS-CoV-2 IgG (sCOVG) assay. Methods Sensitivity and specificity of the Siemens sCOVG test were evaluated on 178 patients with SARS-CoV-2-infection and 160 pre-pandemic samples in comparison with its predecessor test COV2G. Furthermore, correlation with virus neutralization titers was investigated on 134 samples of convalescent COVID-19 patients. Results Specificity of the sCOVG test was 99.4% and sensitivity was 90.5% (COV2G assay 78.7%; p<0.0001). S1-RBD antibody levels showed a good correlation with virus neutralization titers (r=0.843; p<0.0001) and an overall qualitative agreement of 98.5%. Finally, median S1-RBD IgG levels increase with age and were significantly higher in hospitalized COVID-19 patients (median levels general ward: 25.7 U/mL; intensive care: 59.5 U/mL) than in outpatients (3.8 U/mL; p<0.0001). Conclusions Performance characteristics of the sCOVG assay have been improved compared to the predecessor test COV2G. Quantitative SARS-CoV-2 S1-RBD IgG levels could be used as a surrogate for virus neutralization capacity. Further harmonization of antibody quantification might assist to monitor the humoral immune response after COVID-19 disease or vaccination.

scholarly journals Clinical validation of the quantitative Siemens SARS-CoV-2 spike IgG assay (sCOVG) reveals improved sensitivity and a good correlation with virus neutralization titers

2021 ◽  
Author(s):  
Christian Irsara ◽  
Alexander E. Egger ◽  
Wolfgang Prokop ◽  
Manfred Nairz ◽  
Lorin Loacker ◽  
...  
Keyword(s):  
Immune Response ◽  
Clinical Performance ◽  
General Ward ◽  
Virus Neutralization ◽  
Clinical Validation ◽  
Receptor Binding Domain ◽  
Specific Antibody Response ◽  
Neutralization Capacity ◽  
Humoral Immune ◽  
Antibody Levels

AbstractObjectivesSevere Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infections cause Coronavirus Disease 2019 (COVID-19) and induce a specific antibody response. Serological assays detecting IgG against the receptor binding domain (RBD) of the spike (S) protein are useful to monitor the immune response after infection or vaccination. The objective of our study was to evaluate the clinical performance of the Siemens SARS-CoV-2 IgG (sCOVG) assay.MethodsSensitivity and specificity of the Siemens sCOVG test were evaluated on 178 patients with SARS-CoV-2-infection and 160 pre-pandemic samples in comparison with its predecessor test COV2G. Furthermore, correlation with virus neutralization titers was investigated on 134 samples of convalescent COVID-19 patients.ResultsSpecificity of the sCOVG test was 99.4% and sensitivity was 90.5% (COV2G assay 78.7%; p<0.0001). S1-RBD antibody levels showed a good correlation with virus neutralization titers (r=0.843; p<0.0001) and an overall qualitative agreement of 98.5%. Finally, median S1-RBD IgG levels increase with age and were significantly higher in hospitalized COVID-19 patients (median levels general ward: 25.7 U/ml; intensive care: 59.5 U/ml) than in outpatients (3.8 U/ml; p<0.0001).ConclusionsPerformance characteristics of the sCOVG assay have been improved compared to the predecessor test COV2G. Quantitative SARS-CoV-2 S1-RBD IgG levels could be used as a surrogate for virus neutralization capacity. Further harmonization of antibody quantification might assist to monitor the humoral immune response after COVID-19 disease or vaccination.

scholarly journals Maternally Derived Antibody Levels Influence on Vaccine Protection against PCV2d Challenge

Animals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 2231
Author(s):  
István Kiss ◽  
Krisztina Szigeti ◽  
Zalán G. Homonnay ◽  
Vivien Tamás ◽  
Han Smits ◽  
...  
Keyword(s):  
Immune Response ◽  
Humoral Immune Response ◽  
Subunit Vaccine ◽  
Porcine Circovirus Type ◽  
Porcine Circovirus ◽  
Vaccine Protection ◽  
Humoral Immune ◽  
Negative Effect ◽  
Antibody Levels

Piglets from a porcine circovirus type 2 (PCV2) stable farm of low and high levels of maternally derived antibodies (MDA) against PCV2 were vaccinated either with a whole virus type or a PCV2 ORF2 antigen-based commercial subunit vaccine at three weeks of age. Two non-vaccinated groups served as low and high MDA positive controls. At four weeks post vaccination, all piglets were challenged with a PCV2d-2 type virus strain and were checked for parameters related to vaccine protection over a four-week observation period. MDA levels evidently impacted the outcome of the PCV2d-2 challenge in non-vaccinated animals, while it did not have a significant effect on vaccine-induced protection levels. The humoral immune response developed faster in the whole virus vaccinates than in the subunit vaccinated pigs in the low MDA groups. Further, high MDA levels elicited a stronger negative effect on the vaccine-induced humoral immune response for the subunit vaccine than for the whole virus vaccine. The group-based oral fluid samples and the group mean viraemia and faecal shedding data correlated well, enabling this simple, and animal welfare-friendly sampling method for the evaluation of the PCV2 viral load status of these nursery piglets.

scholarly journals Dynamics of humoral immune response in pregnant mares and foals vaccinated with Theileria equi recombinant EMA-2

2018 ◽  
Vol 38 (6) ◽  
pp. 1105-1109
Author(s):  
Alice C. Santos ◽  
Fábio P.L. Leite ◽  
Ana M. Vianna ◽  
Guilherme B. Weege ◽  
Ilusca S. Finger ◽  
...  
Keyword(s):  
Immune Response ◽  
Humoral Immune Response ◽  
Fold Increase ◽  
Serum Levels ◽  
Vaccination Schedule ◽  
Theileria Equi ◽  
Humoral Immune ◽  
Baseline Values ◽  
Antibody Levels ◽  
First Time

ABSTRACT: Theileria equi is an infectious hemoprotozoan agent of equine piroplasmosis, a disease that has severe economic and sanitary impact internationally. In addition to its common clinical features, piroplasmosis can cause gestational losses and neonatal damage, which makes neonates susceptible to this disease. The aim of this study was to evaluate the dynamics of humoral immune response to recombinant EMA-2 of T. equi in pregnant mares and foals, as well as the transfer of vaccine antibodies through the colostrum ingested by sucking foals. For vaccine production, the EMA-2 expression gene was cloned and expressed in the yeast species, Pichia pastoris. Thirty-six horses were used, of which 18 were pregnant mares and 18 were foals. The mares were divided into control and vaccinated groups, and the vaccinated group received three doses of rEMA-2 every 21 days starting at 300 days of gestation. Foals from vaccinated and control groups were evaluated until the sixth month of life. The production of antibodies by foals on the rEMA-2 vaccination schedule was also evaluated from the second month of life. Foals in the vaccinated group had received three doses of the vaccine every 21 days. The method used to evaluate serum and colostrum samples was indirect ELISA, and plates were sensitized with the rEMA-2 protein. At the end of the vaccination schedule, vaccinated mares showed a 2.3-fold increase in antibody levels when compared to baseline values. The colostrum of vaccinated mares presented antibody levels of 1.0432±0.33. Foals delivered by vaccinated mares presented levels of antibodies greater than those of foals delivered by control mares after their first time sucking (at about twelve hours after birth). Foals vaccinated in the second month of life showed an 8.3-fold increase in antibody levels when compared to baseline values. The vaccination schedule with rEMA-2 was able to stimulate humoral immunity in pregnant mares. Vaccine immunoglobins were concentrated in the colostrum of vaccinated mares and foals delivered by these mares showed an increase in serum levels of vaccine antibodies after the first-time sucking.

scholarly journals Recombinant Mycobacterium paragordonae Expressing SARS-CoV-2 Receptor-Binding Domain as a Vaccine Candidate Against SARS-CoV-2 Infections

2021 ◽  
Vol 12 ◽  
Author(s):  
Byoung-Jun Kim ◽  
Hyein Jeong ◽  
Hyejun Seo ◽  
Mi-Hyun Lee ◽  
Hyun Mu Shin ◽  
...  
Keyword(s):  
Immune Response ◽  
Single Dose ◽  
Immune Responses ◽  
Receptor Binding ◽  
Humoral Immune Response ◽  
Vaccine Candidate ◽  
Binding Domain ◽  
Receptor Binding Domain ◽  
Live Virus ◽  
Humoral Immune

At present, concerns that the recent global emergence of SARS-CoV-2 variants could compromise the current vaccines have been raised, highlighting the urgent demand for new vaccines capable of eliciting T cell-mediated immune responses, as well as B cell-mediated neutralizing antibody production. In this study, we developed a novel recombinant Mycobacterium paragordonae expressing the SARS-CoV-2 receptor-binding domain (RBD) (rMpg-RBD-7) that is capable of eliciting RBD-specific immune responses in vaccinated mice. The potential use of rMpg-RBD-7 as a vaccine for SARS-CoV-2 infections was evaluated in in vivo using mouse models of two different modules, one for single-dose vaccination and the other for two-dose vaccination. In a single-dose vaccination model, we found that rMpg-RBD-7 versus a heat-killed strain could exert an enhanced cell-mediated immune (CMI) response, as well as a humoral immune response capable of neutralizing the RBD and ACE2 interaction. In a two-dose vaccination model, rMpg-RBD-7 in a two-dose vaccination could also exert a stronger CMI and humoral immune response to neutralize SARS-CoV-2 infections in pseudoviral or live virus infection systems, compared to single dose vaccinations of rMpg-RBD or two-dose RBD protein immunization. In conclusion, our data showed that rMpg-RBD-7 can lead to an enhanced CMI response and humoral immune responses in mice vaccinated with both single- or two-dose vaccination, highlighting its feasibility as a novel vaccine candidate for SARS-CoV-2. To the best of our knowledge, this study is the first in which mycobacteria is used as a delivery system for a SARS-CoV-2 vaccine.

Erythropoietin Augments Antibody Response to DNP in Immunized Mice.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 4232-4232
Author(s):  
Lidor Yeyni ◽  
Odelia Katz ◽  
Sari Prutchi-Sagiv ◽  
Alon Skaat ◽  
Eran Barzilay ◽  
...  
Keyword(s):  
Immune Response ◽  
Initial Phase ◽  
Recombinant Human Erythropoietin ◽  
Keyhole Limpet Hemocyanin ◽  
Hemodialysis Patients ◽  
Humoral Immune ◽  
Human Erythropoietin ◽  
Antibody Levels ◽  
Control Antigen ◽  
Main Growth

Abstract Recombinant human erythropoietin (rHuEpo), the main growth regulator of red blood cells, has been used in clinical practice for the treatment of anemia of various etiologies. Over the last decade several reports have indicated that the action of Epo is not restricted to the erythroid lineage. Studies indicate that rHuEpo treatment may have an immunomodulatory effect on hemodialysis patients. Here we address the effects of rHuEpo on the humoral immune response of mice. Naïve BALB/c mice (two groups of 16 mice each) were immunized with 2mg antigen dinitrophenylated keyhole limpet hemocyanin (DNP-KLH). Concomitant to antigen injection, the mice were injected three times weekly with rHuEpo (180U per injection) or with diluent (control). Blood samples were taken 2 and 4 weeks after immunization and anti-DNP antibody levels were measured by ELISA. Production of anti DNP antibodies increased significantly (1.5–2 fold) in the initial phase of the response (2 weeks following DNP-KLH injection) in mice injected with rHuEpo compared to their counterpart control antigen-injected mice, that received diluent only. These data indicate that erythropoietin may have a role in stimulating the humoral arm of the immune system, suggesting an immunomodulatory and/or immunostimulatory role for rHuEpo and may open new avenues in improving the immune response of immunocompromised patients.

scholarly journals A genetic basis for atrophy: dominant non-responsiveness and helicobacter induced gastritis in F1 hybrid mice

Gut ◽  
1999 ◽  
Vol 45 (3) ◽  
pp. 335-340 ◽  
Author(s):  
P Sutton ◽  
J Wilson ◽  
R Genta ◽  
D Torrey ◽  
A Savinainen ◽  
...  
Keyword(s):  
Immune Response ◽  
Serum Antibody ◽  
Antibody Responses ◽  
Host Factors ◽  
Mouse Strains ◽  
F1 Hybrid ◽  
Helicobacter Felis ◽  
Humoral Immune ◽  
Antibody Levels ◽  
Hybrid Mice

BACKGROUNDThe importance of host factors in helicobacter induced gastritis has been shown in animal models. Infection of most mouse strains withHelicobacter felis results in a functional atrophic gastritis, while other strains remain gastritis free.AIMSTo investigate these host factors further by using genetic crosses of responder and non-responder mice.METHODSF1 hybrids of the non-responder CBA/Ca strain and three strains of mice known to develop H felis induced gastritis were infected for three months with H felis. Gastritis was assessed by histopathology and serum antibody responses by ELISA.RESULTSInfection of CBA/Ca mice and F1 hybrids induced little or no gastritis. Analyses of the antibody responses in these mice revealed virtually undetectable anti-helicobacter antibody levels despite colonisation with high numbers of H felis. In contrast, infection of H felis responsive strains induced gastritis and a significant humoral immune response.CONCLUSIONSThe non-responsiveness of CBA/Ca mice to H felis infection is dominantly inherited. The lack of gastritis in CBA mice and their offspring is probably due to active suppression of the immune response normally mounted against H felis. Investigation of these mechanisms will provide important insights relevant to induction of gastric atrophy and cancer in humans.

B subunit ofEscherichia coliheat-labile enterotoxin as adjuvant of humoral immune response in recombinant BCG vaccination

2008 ◽  
Vol 54 (8) ◽  
pp. 677-686 ◽  
Author(s):  
Andréa da Silva Ramos Rocha ◽  
Fabricio Rochedo Conceição ◽  
André Alex Grassmann ◽  
Valeska Lizzi Lagranha ◽  
Odir Antônio Dellagostin
Keyword(s):  
Immune Response ◽  
Humoral Immune Response ◽  
Biological Properties ◽  
Adjuvant Effect ◽  
Strong Immune Response ◽  
Humoral Immune ◽  
B Subunit ◽  
Th2 Immune Response ◽  
Antibody Levels ◽  
Recombinant Bcg

The B subunit of Escherichia coli heat-labile enterotoxin (LTB), a nontoxic molecule with potent biological properties, is a powerful mucosal and parenteral adjuvant that induces a strong immune response against co-administered or coupled antigens. In this paper, the effect of LTB on the humoral immune response to recombinant BCG (rBCG) vaccination was evaluated. Isogenic mice were immunized with rBCG expressing the R1 repeat region of the P97 adhesin of Mycoplasma hyopneumoniae alone (rBCG/R1) or fused to LTB (rBCG/LTBR1). Anti-R1 systemic antibody levels (IgG1, IgG2a, IgG2b, IgG3, IgM, and IgA) were measured by ELISA using recombinant R1 as antigen. With the exception of IgM, LTB doubled the anti-R1 antibody levels in rBCG vaccination. The IgG1/IgG2a mean ratio showed that both rBCG/LTBR1 and rBCG/R1 induced a mixed Th1/Th2 immune response. Interestingly, anti-R1 serum IgA was induced only by rBCG/LTBR1. These results demonstrate that LTB has an adjuvant effect on the humoral immune response to recombinant antigens expressed in BCG.

scholarly journals Development of a Unique Rapid Test to Detect Anti-bodies Directed Against an Extended RBD of SARS-CoV-2 Spike Protein

2021 ◽  
Vol 75 (5) ◽  
pp. 446-452
Author(s):  
Larissa Brosi ◽  
Eric Kübler ◽  
Anna Weston ◽  
Patrick Romann ◽  
Sherin Panikulam ◽  
...  
Keyword(s):  
Immune Response ◽  
Receptor Binding ◽  
Recombinant Expression ◽  
Rapid Test ◽  
High Sensitivity ◽  
Spike Protein ◽  
Receptor Binding Domain ◽  
Serological Testing ◽  
Humoral Immune ◽  
Previous Infection

Serological testing for antibodies directed against SARS-CoV-2 in patients may serve as a diagnostic tool to verify a previous infection and as surrogate for an elicited humoral immune response, ideally conferring immunity after infection or vaccination. Here, we present the recombinant expression of an extended receptor binding domain (RBD) of the SARS-CoV-2 Spike protein used as capture antigen in a unique rapid immunoassay to detect the presence of RBD binding antibodies with high sensitivity and specificity. As currently available vaccines focus on the Spike RBD as target, the developed test can also be used to monitor a successful immune response after vaccination with an RBD based vaccine.

scholarly journals Vaccinated Patients Admitted in ICU with Severe Pneumonia Due to SARS-CoV2: A Multicenter Pilot Study

2021 ◽  
Vol 11 (11) ◽  
pp. 1086
Author(s):  
Ángel Estella ◽  
Mª Luisa Cantón ◽  
Laura Muñoz ◽  
Isabel Rodriguez Higueras ◽  
María Recuerda Núñez ◽  
...  
Keyword(s):  
Immune Response ◽  
Acute Respiratory Distress Syndrome ◽  
Cohort Study ◽  
Pilot Study ◽  
Distress Syndrome ◽  
Serum Antibody ◽  
Severe Pneumonia ◽  
Clinical Profile ◽  
Humoral Immune ◽  
Antibody Levels

Background: The aim of this study was to analyze the percentage of patients admitted to the ICU having received the vaccine against COVID-19, to describe the clinical profile of vaccinated patients admitted to the ICU, and to assess the humoral immune response to vaccination. Methods: In this multicenter prospective descriptive cohort study, consecutive critically ill patients with confirmed SARS-CoV-2 pneumonia who received at least one dose of the SARS-CoV2 vaccine were included. The time of study was from 1 July to 10 August of 2021. Results: Of the 94 consecutive patients from seven Andalusian ICUs admitted during the time of study, 50 (53.2%) received at least one dose of anti SARS-CoV2 vaccine. No patient was admitted having previously had SARS-CoV2 infection. The B.1.617.2 (Delta) variant was the most frequently identified, in 80.76% of cases. Patients with a complete vaccination with non-optimal antibody levels were immunocompromised. Fifteen patients were admitted to the ICU with Acute Respiratory Distress Syndrome (ARDS) without having completed their vaccination; the clinical profile was younger and with less comorbidities compared to patients with full vaccination. There were no differences in severity of ARDS. Conclusions: Most of the patients who were admitted to the ICU having received a dose of the vaccine were not optimally vaccinated; fully vaccinated patients who did not obtain optimal serum antibody levels were patients considered immunocompromised.

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