scholarly journals Evaluating SARS-CoV-2 spike and nucleocapsid proteins as targets for IgG antibody detection in severe and mild COVID-19 cases using a Luminex bead-based assay

2020 ◽  
Author(s):  
Joachim Marien ◽  
Johan Michiels ◽  
Leo Heyndrickx ◽  
Karen Kerkhof ◽  
Nikki Foque ◽  
...  
Keyword(s):  
Large Scale ◽  
Detection Threshold ◽  
Neutralizing Antibody ◽  
Cost Effective ◽  
Antibody Detection ◽  
Igg Antibodies ◽  
Igg Antibody ◽  
Serological Tests ◽  
Specific Igg ◽  
Antibody Levels

Large-scale serosurveillance of severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) will only be possible if serological tests are sufficiently reliable, rapid and inexpensive. Current assays are either labour-intensive and require specialised facilities (e.g. virus neutralization assays), or expensive with suboptimal specificity (e.g. commercial ELISAs). Bead-based assays offer a cost-effective alternative and allow for multiplexing to test for antibodies of other pathogens. Here, we compare the performance of four antigens for the detection of SARS-CoV-2 specific IgG antibodies in a panel of sera that includes both severe (n=40) and mild (n=52) cases, using a neutralization and a Luminex bead-based assay. While we show that neutralising antibody levels are significantly lower in mild than in severe cases, we demonstrate that a combination of recombinant nucleocapsid protein (NP), receptor-binding domain (RBD) and the whole spike protein (S1S2) results in a highly sensitive (96%) and specific (99%) bead-based assay that can detect IgG antibodies in both groups. Although S1-specific IgG levels correlate most strongly with neutralizing antibody levels, they fall below the detection threshold in 10% of the cases in our Luminex assay. In conclusion, our data supports the use of RBD, NP and S1S2 for the development of SARS-CoV-2 serological bead-based assays. Finally, we argue that low antibody levels in mild/asymptomatic cases might complicate the epidemiological assessment of large-scale surveillance studies.

scholarly journals Comparative analysis of three point-of-care lateral flow immunoassays for detection of anti-SARS-CoV-2 antibodies in COVID-19 confirmed healthcare workers

2020 ◽  
Author(s):  
Danielle Dias Conte ◽  
Joseane Mayara Almeida Carvalho ◽  
Luciano Kleber de Souza Luna ◽  
Klinger Soares Faíco-Filho ◽  
Ana Helena Perosa ◽  
...  
Keyword(s):  
Healthcare Workers ◽  
Large Scale ◽  
Point Of Care ◽  
Antibody Test ◽  
Cost Effective ◽  
Lateral Flow ◽  
Rt Pcr ◽  
Serum Samples ◽  
Igg Antibody ◽  
Serological Tests

AbstractSince the Coronavirus Disease 2019 (COVID-19) pandemic, Brazil has the third-highest number of confirmed cases and the second-highest number of recovered patients. SARS-CoV-2 detection by real-time RT-PCR is the gold standard in certified infrastructured laboratories. However, for large-scale testing, diagnostics should be fast, cost-effective, widely available, and deployed for the community, such as serological tests based on lateral flow immunoassay (LFIA) for IgM/IgG detection. We evaluated three different commercial point-of-care (POC) LFIAs for anti-SARS-CoV-2 IgM and IgG detection in capillary whole blood of 100 healthcare workers (HCW) previously tested by RT-PCR: 1) COVID-19 IgG/IgM BIO (Bioclin, Brazil), 2) Diagnostic kit for IgM/IgG Antibody to Coronavirus (SARS-CoV-2) (Livzon, China); and 3) SARS-CoV-2 Antibody Test (Wondfo, China). A total of 84 positives and 16 negatives HCW were tested. The data was also analyzed by the number of days post symptoms (DPS) in three groups: <30 (n=26), 30-59 (n=42), and >59 (n=16). Overall detection was 85.71%, 47.62%, and 44.05% for Bioclin, Livzon, and Wondfo, respectively, with a specificity of 100%, and 98.75% for Livzon on storage serum samples. Bioclin was more sensitive (p<0.01), regardless of the DPS. Thus, the Bioclin can be used as a POC test to monitor SARS-CoV-2 seroconversion in HCW.

scholarly journals Immunogenicity of 10-valent pneumococcal conjugate vaccine among infants attending Mbagathi District Hospital, Kenya

F1000Research ◽  
2015 ◽  
Vol 4 ◽  
pp. 165
Author(s):  
Michael Walekhwa ◽  
Margaret Muturi ◽  
Elizabeth Bukusi
Keyword(s):  
Chronic Illness ◽  
Conjugate Vaccine ◽  
Pneumococcal Conjugate Vaccine ◽  
District Hospital ◽  
Maternal Diet ◽  
Igg Antibodies ◽  
Igg Antibody ◽  
Specific Igg ◽  
Socio Demographic Factors ◽  
Antibody Levels

Introduction: This study aimed to determine the serum concentration of IgG antibodies as an indicator of immunogenicity, alongside the assessment of socio-demographic factors that affect IgG antibody levels in infants immunized with 10-valent pneumococcal conjugate vaccine (PCV-10) at the Mbagathi District Hospital in Kenya.Materials and methods: This cross-sectional study measured serum IgG antibodies among infants who had completed a 3-dose course of PCV-10. IgG antibodies to pneumococcal serotype-specific capsular polysaccharide were measured through enzyme-linked immunosorbent assay (ELISA).Results: The majority (83%) of infants who completed the required dose of pneumococcal conjugate vaccine had serum titres of pneumococcal disease- (PD) specific IgG antibodies of between 0.34 mg/dl and 0.36 mg/dl. 4% of infants had serum titres of 0.30 mg/dl to 0.33 mg/dl. The remaining 2% had IgG antibody titres of either ≤0.25 mg/dl, or between 0.25 mg/dl to 0.29 mg/dl. Additionally, there was multi-collinearity among the IgG antibody levels of the infants studied and several variables that had an effect on these levels. These included: alcohol consumption by infants’ biological mothers during pregnancy (r =.595, p ≤ 0.05); maternal diet during pregnancy (r =.137, p ≤ 0.05); breastfeeding frequency (r =.220, p ≤ 0.05); proximity to other children (r =.133, p ≤ 0.05); child hospitalization (r =.131, p ≤ 0.05) and chronic illness (r =.154, p ≤0.01).Conclusion: PCV-10 is immunogenic against PD four weeks after completion of 3-doses among the infants attending the Child Welfare clinic at the Mbagathi District Hospital in Kenya. Socio-demographic factors which include consumption of alcoholic drinks by infant’s biological mother during pregnancy and study infant chronic illness negatively affect the development of PD specific IgG. A balanced maternal diet during pregnancy and a breastfeeding frequency superior to three times per day have a significant positive effect on serum pneumococcal IgG levels among infants.

scholarly journals Seroprevalence, waning, and correlates of anti-SARS-CoV-2 IgG antibodies in Tyrol, Austria: Large-scale study of 35,193 blood donors conducted between June 2020 and September 2021

2021 ◽  
Author(s):  
Anita Siller ◽  
Lisa Seekircher ◽  
Gregor A Wachter ◽  
Manfred Astl ◽  
Lena Tschiderer ◽  
...  
Keyword(s):  
Large Scale ◽  
Blood Donors ◽  
Participation Rate ◽  
Federal State ◽  
Igg Antibodies ◽  
Serum Samples ◽  
Serological Tests ◽  
Nucleocapsid Proteins ◽  
Antibody Levels ◽  
Prior Infection

Background: There is uncertainty about the seroprevalence of anti-SARS-CoV-2 antibodies in the general population of Austria, and about the extent to which antibodies elicited by vaccination or infection wane over time. Aim: To estimate seroprevalence, waning, and correlates of anti-SARS-CoV-2 IgG antibodies in the Federal State of Tyrol, Austria. Methods: We conducted a seroepidemiological study between June 2020 and September 2021, enrolling blood donors aged 18-70 years across Tyrol, Austria (participation rate 84.0%). We analysed serum samples for antibodies against spike or nucleocapsid proteins of SARS-CoV-2 with Abbott SARS-CoV-2 IgG assays. Results: We performed 47,363 serological tests among 35,193 individuals (median age 43.1 years [IQR: 29.3-53.7], 45.3% women, 10.0% with prior SARS-CoV-2 infection). Seroprevalence increased from 3.4% (95% CI: 2.8-4.2%) in June 2020 to 82.7% (95% CI: 81.4-83.8%) in September 2021, largely due to vaccination. Anti-spike IgG seroprevalence was 99.6% (99.4-99.7%) among fully vaccinated individuals, 90.4% (88.8-91.7%) among unvaccinated with prior infection, and 11.5% (10.8-12.3%) among unvaccinated without known prior infection. Anti-spike IgG levels were reduced by 44.0% (34.9-51.7%) at 5-6 months compared to 0-3 months after infection. In fully vaccinated individuals, they decreased by 31.7% (29.4-33.9%) per month. In multivariable adjusted analyses, both seropositivity among unvaccinated and antibody levels among fully vaccinated individuals were higher at young age (<25 years), higher with a known prior infection, and lower in current smokers. Conclusion: Seroprevalence in Tyrol increased to 82.7% in September 2021, with the bulk of seropositivity stemming from vaccination. Antibody levels substantially and gradually declined after vaccination or infection.

scholarly journals Large-Scale Study of Antibody Titer Decay following BNT162b2 mRNA Vaccine or SARS-CoV-2 Infection

Vaccines ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 64
Author(s):  
Ariel Israel ◽  
Yotam Shenhar ◽  
Ilan Green ◽  
Eugene Merzon ◽  
Avivit Golan-Cohen ◽  
...  
Keyword(s):  
Large Scale ◽  
Immune Protection ◽  
Igg Antibodies ◽  
Igg Antibody ◽  
Exponential Decrease ◽  
Previous Infection ◽  
History Of ◽  
Antibody Titers ◽  
Antibody Levels ◽  
Kinetics Of

Immune protection following either vaccination or infection with SARS-CoV-2 is thought to decrease over time. We designed a retrospective study, conducted at Leumit Health Services in Israel, to determine the kinetics of SARS-CoV-2 IgG antibodies following administration of two doses of BNT162b2 vaccine, or SARS-CoV-2 infection in unvaccinated individuals. Antibody titers were measured between 31 January 2021, and 31 July 2021 in two mutually exclusive groups: (i) vaccinated individuals who received two doses of BNT162b2 vaccine and had no history of previous infection with COVID-19 and (ii) SARS-CoV-2 convalescents who had not received the vaccine. A total of 2653 individuals fully vaccinated by two doses of vaccine during the study period and 4361 convalescent patients were included. Higher SARS-CoV-2 IgG antibody titers were observed in vaccinated individuals (median 1581 AU/mL IQR [533.8–5644.6]) after the second vaccination than in convalescent individuals (median 355.3 AU/mL IQR [141.2–998.7]; p < 0.001). In vaccinated subjects, antibody titers decreased by up to 38% each subsequent month while in convalescents they decreased by less than 5% per month. Six months after BNT162b2 vaccination 16.1% subjects had antibody levels below the seropositivity threshold of <50 AU/mL, while only 10.8% of convalescent patients were below <50 AU/mL threshold after 9 months from SARS-CoV-2 infection. This study demonstrates individuals who received the Pfizer-BioNTech mRNA vaccine have different kinetics of antibody levels compared to patients who had been infected with the SARS-CoV-2 virus, with higher initial levels but a much faster exponential decrease in the first group.

scholarly journals The positive rate of IgM and IgG antibodies against SARS-CoV-2 is similar in severe and non-severe COVID-19 patients

2021 ◽  
Vol 29 (1) ◽  
pp. 85-91
Author(s):  
Nan Jiang ◽  
Yaoyao Sun ◽  
Hongyan Sun ◽  
Bo Yang ◽  
Juan Tan ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Diagnostic Method ◽  
Effective Means ◽  
Antibody Detection ◽  
Igg Antibodies ◽  
Igg Antibody ◽  
Nucleic Acid Test ◽  
Positive Rate ◽  
Antibody Levels ◽  
Acid Test

Abstract Background: Coronavirus disease 2019 (COVID-19) has spread rapidly in China and globally. In order to control the spread of the epidemic, it is important to find an efficient diagnostic method. Objectives: The aim of this study was to assess the responses of antibodies during SARS-CoV-2 infection in relation to disease severity and to evaluate the association between the positive rate of antibody detection and nucleic acid test. Methods: Ninety patients with SARS-CoV-2 infection were recruited in this retrospective observational study. Demographic, clinical data, and SARS-CoV-2 IgM and IgG antibodies in serum specimens were detected at 4 and 6 weeks after diagnosis. Results: IgM and IgG antibody levels showed a decreased tendency, the titers at week 4 were higher than the titers at week 6: The positive rates of IgM at week 4 and 6 were 92.9% and 67.9%, respectively. The positive rates of IgG at week 4 and week 6 were 100%. No association was found between the positive rate of antibody detection at week 4 or 6 and that of nucleic acid test (P>0.05). No difference between the positive rate of antibodies against SARS-CoV-2 in severe and non-severe COVID-19 patients was observed. Conclusions: Antibody detection is an effective means in the diagnosis of COVID-19. The titer and positive rate of IgM are lower than those of IgG in the first six weeks after infection. Positive rate of antibodies was not different between severe and non-severe patients.

scholarly journals A Single Drop of Fingerstick Blood for Quantitative Antibody Response Evaluation After SARS-CoV-2 Vaccination

2021 ◽  
Author(s):  
Jinwei Du ◽  
Dayu Zhang ◽  
Hannah May ◽  
Yulia Loginova ◽  
Eric Chu ◽  
...  
Keyword(s):  
Large Scale ◽  
Venous Blood ◽  
Vaccine Dose ◽  
Neutralizing Antibody ◽  
Cost Effective ◽  
Quantitative Detection ◽  
Single Drop ◽  
Antibody Testing ◽  
Igg Antibody ◽  
Blood Draw

Among several COVID vaccines that have been approved, the Moderna and Pfizer-BioNTech vaccines are mRNA vaccines that are safe and highly effective at preventing COVID-19 illness. Studies have demonstrated that neutralizing antibody responses elicited by these vaccines correlate strongly with antibodies measured by immunoassays such as ELISA. To monitor the antibody level duration of vaccine-induced immune responses in vaccinated population, cost-effective and easily implementable antibody testing methodologies are urgently needed. In this study, we evaluated the feasibility of using a single drop of fingerstick blood collected with flocked swabs for a high-throughput and quantitative anti-SARS-CoV-2 spike (S1) IgG antibody immunoassay. A total of 50 voluntary subjects participated and donated fingerstick blood samples before and after receiving the Moderna mRNA vaccine. Among all individuals tested, no anti-SARS-CoV-2 S1 IgG antibody was detected before vaccination and on day 7 after receiving the first vaccine dose. On day 14 after the first dose, a significant amount of anti-SARS-CoV-2 S1 IgG antibody was detected in all participants samples. By the end the third week from the first dose, the median anti-SARS-CoV-2 S1 IgG concentration increased to 44.9 ug/mL. No anti-SARS-CoV-2 nucleocapsid (N) protein IgG antibody was detected in any of the participants during the study period, indicating that the anti-SARS-CoV-2 S1 IgG assay is specific for the mRNA vaccine induced antibodies. Comaprison of venous blood plasma and fingerstick blood for anti-SARS-CoV-2 S1 IgG shown a higher correlation. Furthermore, the fingerstick blood dried swab samples are stable for at least 4 days. In summary, we demonstrated that a single drop of fingerstick blood collected with flocked swab can be used for quantitative detection and monitoring of anti-SARS-CoV-2 spike IgG responses after receiving COVID-19 vaccination. This testing platform does not require venous blood draw and can be easily implemented for large scale antibody testing in vaccinated populations.

scholarly journals Mass Antibody Detection: Can It be An Avenger for Infectivity War against COVID-19

2020 ◽  
Author(s):  
Sarfaraz Ahmad Ejazi ◽  
Sneha Ghosh ◽  
Nahid Ali
Keyword(s):  
Large Scale ◽  
Point Of Care ◽  
Cost Effective ◽  
Antibody Detection ◽  
Serological Tests ◽  
Ongoing Research ◽  
Molecular Tests ◽  
Immunological Assays ◽  
Commercial Kits ◽  
Vaccination Therapy

The ongoing pandemic of COVID-19 has not only commenced a global health emergency but agitated various aspects of humanity. During this period of crisis researchers over the world have ramped their efforts to constrain the disease in all possible ways whether it is vaccination, therapy, or diagnosis. Since the spread of the disease has not yet elapsed sharing the ongoing research findings could be the key to disease control and management. An early and efficient diagnosis could leverage the outcome until a successful vaccine is developed. Molecular tests both in-house and commercial kits are preferably being used worldwide in the COVID-19 diagnosis. However, the limitation of high prices and lengthy procedures impede their use for mass testing. Keeping the constant rise of infection in mind search for an alternative test that should be cost-effective, simple, and suitable for large scale testing and surveillance is a need of an hour. One such alternative could be the immunological tests. Therefore, in the last few months deluge of immunological rapid tests has been developed and validated across the globe. The objective of the present review is to share the diagnostic performance of various immunological assays reported so far in SARS-CoV-2 case detection. The article consolidated the studies (published and preprints) related to the serological tests such as chemiluminescence, enzyme-linked and lateral flow-based point-of-care tests in COVID-19 diagnosis and updated the current scenario. This review will hopefully be an add-on in COVID-19 research and will contribute to congregate the evidence for decision-making.

scholarly journals Application of Food-specific IgG Antibody Detection in Allergy Dermatosis

Open Medicine ◽  
2015 ◽  
Vol 10 (1) ◽  
Author(s):  
Hu Yine ◽  
Dai Shufang ◽  
Wang Bin ◽  
Qu Wei ◽  
Muhammad Aqeel Ashraf ◽  
...  
Keyword(s):  
Antibody Detection ◽  
Igg Antibodies ◽  
Igg Antibody ◽  
Allergic Dermatitis ◽  
Positive Antibody ◽  
Significant Difference ◽  
Positive Rate ◽  
High Incidence Rate ◽  
Specific Igg ◽  
Specific Igg Antibodies

AbstractThe application of food-specific IgG antibody detection in allergy dermatoses was explored. 181 patients with allergy dermatoses were diagnosed from January to September 2014 and 20 healthy subjects were selected. Fourteen kinds of food-specific IgG antibodies were detected by ELISA method among all the subjects. The positive rates of IgG antibody of the patient group and the healthy group were respectively 65.2% and 5.0%. The positive rates of IgG antibody of egg, milk, shrimp and crab took a large proportion in three groups of patients with three kinds of allergy dermatoses of urticaria, eczema and allergic dermatitis, the proportion of which was respectively 70.2%, 77.8% and 71.7%. Among urticaria and allergic dermatitis patients with positive antibody, the positive rate of children was significantly higher than that of adults (p<0.05) while there was no significant difference between children and adults among eczema patients with positive antibody (p>0.05). Allergy dermatoses are closely related to food-specific IgG antibodies, and the allergy dermatoses patients have a high incidence rate of food intolerance; detecting IgG antibody in the serum of patients is of great significance for the diagnosis and treatment of allergy dermatoses.

scholarly journals Stable IgG-antibody levels in patients with mild SARS-CoV-2 infection

2021 ◽  
Author(s):  
Thomas Akerlund ◽  
Katherina Zakikhany ◽  
Charlotta Lofstrom ◽  
Evelina Lindmark ◽  
Henrik Kallberg ◽  
...  
Keyword(s):  
Nucleocapsid Protein ◽  
Spike Protein ◽  
Igg Antibodies ◽  
Serum Samples ◽  
Igg Antibody ◽  
Time Period ◽  
Specific Igg ◽  
Antibody Levels ◽  
Over Time ◽  
Specific Igg Antibodies

More knowledge regarding persistence of antibody response to SARS-CoV-2 infections in the general population with mild symptoms is needed. We measured and compared levels of SARS-CoV-2 spike- and nucleocapsid-specific IgG-antibodies in serum samples from 145 laboratory-confirmed COVID-19 cases and 324 non-cases. The IgG-antibody levels against the spike protein in cases were stable over the time-period studied (14 to 256 days), while antibody levels against the nucleocapsid protein decreased over time.

scholarly journals Assessment of S1, S2 and NCP-specific IgM, IgA, and IgG antibody kinetics in acute SARS-CoV-2 infection by a microarray and twelve other immunoassays

2021 ◽  
Author(s):  
Georg Semmler ◽  
Marianna Theresia Traugott ◽  
Marianne Graninger ◽  
Wolfgang Hoepler ◽  
Tamara Seitz ◽  
...  
Keyword(s):  
Rapid Test ◽  
Tracheal Aspirate ◽  
Target Antigen ◽  
Igg Antibodies ◽  
Igg Antibody ◽  
Detection Rates ◽  
Specific Igg ◽  
Antibody Levels ◽  
Antibody Kinetics ◽  
Specific Igg Antibodies

In this study, we comprehensively analyzed multispecific antibody kinetics of different immunoglobulins in hospitalized patients with acute SARS-CoV-2 infection. Three-hundred-fifty-four blood samples longitudinally obtained from 81 IgG seroconverting CoVID-19 patients were quantified for spike (S)1, S2, and nucleocapsid protein (NCP)- specific IgM, IgA, IgG, and total Ig antibodies using a microarray, eleven different ELISAs/CLIAs, and one rapid test by seven manufacturers. The assays’ specificity was assessed in 130 non-CoVID19 pneumonia patients. Using the microarray, NCP-specific IgA and IgG antibodies continuously displayed higher detection rates during acute CoVID-19 than S1- and S2-specific ones. S1-specific IgG antibodies, however, reached higher peak values. Until the 26th-day post symptom onset, all patients developed IgG responses against S1, S2, and NCP, respectively. Although detection rates by ELISAs/CLIAs generally resembled those of the microarray, corresponding to the target antigen, sensitivities and specificities varied among all tests. Notably, patients with more severe CoVID-19 displayed higher IgG and IgA levels, but this difference was mainly observed with S1-specific immunoassays. In patients with high SARS-CoV-2 levels in the lower respiratory tract, we observed high detection rates of IgG and total Ig immunoassays with a particular rise of S1-specific IgG antibodies when viral concentrations in the tracheal aspirate subsequently declined over time. In summary, our study demonstrates that differences in sensitivity among commercial immunoassays during acute SARS-CoV-2 infection are only partly related to the target antigen. Importantly, our data indicate that NCP-specific IgA and IgG antibodies are detected earlier, while higher S1-specific IgA antibody levels occur in severely ill patients.

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