scholarly journals Immunogenicity of a third dose viral-vectored COVID-19 vaccine after receiving two-dose inactivated vaccines in healthy adults

2021 ◽  
Author(s):  
Ritthideach Yorsaeng ◽  
Nungruthai Suntronwong ◽  
Harit Phowatthanasathian ◽  
Suvichada Assawakosri ◽  
Sitthichai Kanokudom ◽  
...  
Keyword(s):  
Healthcare Workers ◽  
Neutralization Test ◽  
Enzyme Linked Immunosorbent Assay ◽  
Receptor Binding Domain ◽  
Wild Type ◽  
Serum Samples ◽  
Inactivated Vaccines ◽  
Specific Igg ◽  
June July ◽  
High Immunogenicity

In June 2021, Thailand was hit by the delta variant of SARS-CoV-2 resulting in the biggest wave of COVID-19. Due to the widespread delta variant, more than 600 healthcare workers had COVID-19 despite completion of two-dose CoronaVac. The Ministry of Public Health recommended that healthcare workers received a third dose of AZD1222 to increase level of protection against SARS-CoV-2. However, immune response after the third vaccination with AZD1222 are limited. In this study, sera from those who received a booster of AZD1222 in June-July 2021 were tested for SARS-CoV-2 spike receptor-binding-domain (RBD) IgG, anti-RBD total immunoglobulins and anti-spike protein 1 (S1) IgA. The neutralizing activities in a subset of serum samples were tested against the wild type and variants of concern (B.1.1.7, B.1.617.2, and B.1.351) using an enzyme-linked immunosorbent assay-based surrogate virus neutralization test. Participants who received the booster of AZD1222 possessed higher levels of spike RBD-specific IgG, total immunoglobulins, and anti-S1 IgA than that two-dose vaccines (p < 0.001). They also elicited higher neutralizing activity against the wild type and all variants of concern than those in the recipients of the two-dose vaccines. This study demonstrated a high immunogenicity of the AZD1222 booster who completed the two-dose inactivated vaccines.

scholarly journals SARS-CoV-2 Seroprevalence in Healthcare Workers of Kaunas Hospitals during the First Wave of the COVID-19 Pandemic

Medicina ◽  
2021 ◽  
Vol 57 (2) ◽  
pp. 148 ◽  
Author(s):  
Laura Pereckaitė ◽  
Asta Dambrauskienė ◽  
Daiva Urbonienė ◽  
Saulius Sadauskas ◽  
Kęstutis Petrikonis ◽  
...  
Keyword(s):  
Healthcare Workers ◽  
Lateral Flow ◽  
Immunoglobulin M ◽  
Lateral Flow Immunoassay ◽  
Enzyme Linked Immunosorbent Assay ◽  
Antibody Testing ◽  
Serum Samples ◽  
Positive Group ◽  
Percent Agreement ◽  
Specific Igg

Background and objective: Serologic testing is a useful additional method for the diagnosis of COVID-19. It is also used for population-based seroepidemiological studies. The objective of the study was to determine SARS-CoV-2 seroprevalence in healthcare workers of Kaunas hospitals and to compare two methods for specific SARS-CoV-2 antibody testing. Materials and Methods: A total of 432 healthcare workers in Kaunas hospitals were enrolled in this study. Each participant filled a questionnaire including questions about their demographics, contact with suspected or confirmed COVID-19, acute respiratory symptoms, and whether they contacted their general practitioner, could not come to work, or had to be hospitalized. Capillary blood was used to test for SARS-CoV-2 specific immunoglobulin G (IgG) and immunoglobulin M (IgM) a lateral flow immunoassay. Serum samples were used to test for specific IgG and IgA class immunoglobulins using semiquantitative enzyme-linked immunosorbent assay (ELISA) method. Results: 24.77% of study participants had direct contact with a suspected or confirmed case of COVID-19. A total of 64.81% of studied individuals had at least one symptom representing acute respiratory infection, compatible with COVID-19. Lateral flow immunoassay detected SARS-CoV-2 specific IgG class immunoglobulins in 1.16% of the tested group. Fever, cough, dyspnea, nausea, diarrhea, headache, conjunctivitis, muscle pain, and loss of smell and taste predominated in the anti-SARS-CoV-2 IgG-positive group. Using ELISA, specific IgG were detected in 1.32% of the tested samples. Diarrhea, loss of appetite, and loss of smell and taste sensations were the most predominant symptoms in anti-SARS-CoV-2 IgG-positive group. The positive percent agreement of the two testing methods was 50%, and negative percent agreement was 99.66%. Conclusions: 1.16% of tested healthcare workers of Kaunas hospitals were anti-SARS-CoV-2 IgG-positive. The negative percent agreement of the lateral flow immunoassay and ELISA exceeded 99%.

scholarly journals COMPARISON OF RESULTS OBTAINED BY ELISA AND NEUTRALIZATION TEST IN ASSESSING THE PROTECTION OF POPULATION FROM TICK-BORNE ENCEPHALITIS

2018 ◽  
Vol 63 (1) ◽  
pp. 36-40 ◽  
Author(s):  
L. L. Chernokhaeva ◽  
G. B. Maikova ◽  
Yu. V. Rogova ◽  
V. V. Romanenko ◽  
A. V. Ankudinova ◽  
...  
Keyword(s):  
Blood Serum ◽  
Neutralizing Antibodies ◽  
Neutralization Test ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Protection Level ◽  
Tick Borne Encephalitis ◽  
Inactivated Vaccines ◽  
Total Pool ◽  
The Difference

The enzyme-linked immunosorbent assay (ELISA) and the neutralization test (NT) are often used to determine the level of seropositive population and to evaluate the immunogenicity of vaccines. ELISA provides information on the total pool of antiviral antibodies, while NT allows the antiviral protection level of a person to be estimated. It is assumed that the 1:100 titer in ELISA and the 1:10 titer in NT are protective. Obviously, the ratio of the total pool and virus neutralizing antibodies can vary as a result of natural immunization or vaccination. In this study, two methods were used to study the blood serum samples taken in a group of inhabitants of the Sverdlovsk region aged from 1 to 60 years. The samples were collected before immunization and 30 days after two immunizations with inactivated vaccines against tick-borne encephalitis of different manufacturers. Immunizations were performed either according to a standard scheme (30-day interval between immunizations), or according to an emergency scheme (14-day interval). It was shown that the data on the presence of antiviral antibodies in protective titers obtained by ELISA and NT were consistent in more than 85% of cases. The discrepancies between the data are due, in the first place, to the difference in the sensitivities of the two methods. The proportion of seropositive people according to NT data is always greater than that according to the results of ELISA. Nevertheless, among 174 children, about 5% of recipients after a double immunization were seropositive according to ELISA, but did not have neutralizing antibodies in protective titers.

scholarly journals Development of SARS-CoV-2 Specific IgG and Virus-Neutralizing Antibodies after Infection with Variants of Concern or Vaccination

Vaccines ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 700
Author(s):  
Franziska Neumann ◽  
Ruben Rose ◽  
Janine Römpke ◽  
Olaf Grobe ◽  
Thomas Lorentz ◽  
...  
Keyword(s):  
Immune Response ◽  
Receptor Binding ◽  
Neutralizing Antibodies ◽  
Neutralization Test ◽  
Vaccine Dose ◽  
High Avidity ◽  
Receptor Binding Domain ◽  
Robust Immune Response ◽  
Specific Igg ◽  
Nucleoprotein N

The humoral immunity after SARS-CoV-2 infection or vaccination was examined. Convalescent sera after infection with variants of concern (VOCs: B.1.1.7, n = 10; B.1.351, n = 1) and sera from 100 vaccinees (Pfizer/BioNTech, BNT162b2, n = 33; Moderna, mRNA-1273, n = 11; AstraZeneca, ChAdOx1 nCoV-19/AZD1222, n = 56) were tested for the presence of immunoglobulin G (IgG) directed against the viral spike (S)-protein, its receptor-binding domain (RBD), the nucleoprotein (N) and for virus-neutralizing antibodies (VNA). For the latter, surrogate assays (sVNT) and a Vero-cell based neutralization test (cVNT) were used. Maturity of IgG was determined by measuring the avidity in an immunoblot (IB). Past VOC infection resulted in a broad reactivity of anti-S IgG (100%), anti-RBD IgG (100%), and anti-N IgG (91%), while latter were absent in 99% of vaccinees. Starting approximately two weeks after the first vaccine dose, anti-S IgG (75–100%) and particularly anti-RBD IgG (98–100%) were detectable. After the second dose, their titers increased and were higher than in the convalescents. The sVNT showed evidence of VNA in 91% of convalescents and in 80–100%/100% after first/second vaccine dose, respectively. After the second dose, an increase in VNA titer and IgGs of high avidity were demonstrated by cVNT and IB, respectively. Re-vaccination contributes to a more robust immune response.

scholarly journals Monoclonal Antibody-Based Antigen Capture Enzyme-Linked Immunosorbent Assay Reveals High Sensitivity of the Nucleocapsid Protein in Acute-Phase Sera of Severe Acute Respiratory Syndrome Patients

2005 ◽  
Vol 12 (1) ◽  
pp. 135-140 ◽  
Author(s):  
Biao Di ◽  
Wei Hao ◽  
Yang Gao ◽  
Ming Wang ◽  
Ya-di Wang ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Acute Phase ◽  
Detection Rate ◽  
Neutralization Test ◽  
Protein Detection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
N Protein ◽  
Antigen Capture ◽  
Healthy Donors

ABSTRACT Accurate and timely diagnosis of severe acute respiratory syndrome coronavirus (SARS-CoV) infection is a critical step in preventing another global outbreak. In this study, 829 serum specimens were collected from 643 patients initially reported to be infected with SARS-CoV. The sera were tested for the N protein of SARS-CoV by using an antigen capture enzyme-linked immunosorbent assay (ELISA) based on monoclonal antibodies against the N protein of SARS-CoV and compared to 197 control serum samples from healthy donors and non-SARS febrile patients. The results of the N protein detection analysis were directly related to the serological analysis data. From 27 SARS patients who tested positive with the neutralization test, 100% of the 24 sera collected from 1 to 10 days after the onset of symptoms were positive for the N protein. N protein was not detected beyond day 11 in this group. The positive rates of N protein for sera collected at 1 to 5, 6 to 10, 11 to 15, and 16 to 20 days after the onset of symptoms for 414 samples from 298 serologically confirmed patients were 92.9, 69.8, 36.4, and 21.1%, respectively. For 294 sera from 248 serological test-negative patients, the rates were 25.6, 16.7, 9.3, and 0%, respectively. The N protein was not detected in 66 patients with cases of what was initially suspected to be SARS but serologically proven to be negative for SARS and in 197 serum samples from healthy donors and non-SARS febrile patients. The specificity of the assay was 100%. Furthermore, of 16 sera collected from four patients during the SARS recurrence in Guangzhou, 5 sera collected from 7 to 9 days after the onset of symptoms were positive for the N protein. N protein detection exhibited a high positive rate, 96 to 100%, between day 3 and day 5 after the onset of symptoms for 27 neutralization test-positive SARS patients and 298 serologically confirmed patients. The N protein detection rate continually decreased beginning with day 10, and N protein was not detected beyond day 19 after the onset of symptoms. In conclusion, an antigen capture ELISA reveals a high N protein detection rate in acute-phase sera of patients with SARS, which makes it useful for early diagnosis of SARS.

scholarly journals Correlation of the commercial anti-SARS-CoV-2 receptor binding domain antibody test with the chemiluminescent reduction neutralizing test and possible detection of antibodies to emerging variants

2021 ◽  
Author(s):  
Yoshitomo Morinaga ◽  
Hideki Tani ◽  
Yasushi Terasaki ◽  
Satoshi Nomura ◽  
Hitoshi Kawasuji ◽  
...  
Keyword(s):  
Receptor Binding ◽  
Disease Onset ◽  
Antibody Test ◽  
Binding Domain ◽  
Receptor Binding Domain ◽  
Healthy Individuals ◽  
Wild Type ◽  
Serum Samples ◽  
Serological Tests ◽  
Convalescent Phase

Background Serological tests are beneficial for recognizing the immune response against SARS-CoV-2. To identify protective immunity, optimization of the chemiluminescent reduction neutralizing test (CRNT), using pseudotyped SARS-CoV-2, is critical. Whether commercial antibody tests are comparably accurate is unknown. Methods Serum samples collected before variants were locally found were obtained from confirmed COVID-19 patients (n = 74), confirmed non-COVID-19 individuals (n = 179), and unscreened individuals (suspected healthy individuals, n = 229). The convalescent phase was defined as the period after day 10 from disease onset. The CRNT against pseudotyped viruses displaying the wild-type spike protein and a commercially available anti-receptor binding domain (RBD) antibody test were assayed. The CRNT was also assayed, using South African (SA) and United Kingdom (UK)-derived variants. Results The CRNT (cut off value, 50% inhibition) and the anti-RBD antibody test (cut off value, 0.8 U/mL) concurred regarding symptomatic COVID-19 patients in the convalescent phase and clearly differentiated between patients and suspected healthy individuals (sensitivity; 95.8% and 100%, specificity; 99.1% and 100%, respectively). Anti-RBD antibody test results correlated with neutralizing titer (r = 0.47, 95% CI 0.20-0.68). Compared with the wild-type, CRNT reduction was observed for the SA and UK-derived variants. Of the samples with ≥100 U/mL by the anti-RBD antibody test, 77.8% and 88.9% showed ≥50% neutralization against the UK and the SA variants, respectively. Conclusion The CRNT and commercial anti-RBD antibody test effectively classified convalescent COVID-19 patients. The strong positive results using the commercial antibody test can reflect neutralizing activity against emerging variants.

scholarly journals Immunogenicity of heterologous prime/booster-inactivated and adenoviral-vectored COVID-19 vaccine: real-world data

2021 ◽  
Author(s):  
Nasamon Wanlapakorn ◽  
Nungruthai Suntronwong ◽  
Harit Phowatthanasathian ◽  
Ritthideach Yorsang ◽  
Thanunrat Thongmee ◽  
...  
Keyword(s):  
Neutralizing Antibody ◽  
Enzyme Linked Immunosorbent Assay ◽  
Antibody Activity ◽  
Serum Samples ◽  
Real World Data ◽  
Comparison Groups ◽  
Chemiluminescent Microparticle Immunoassay ◽  
Specific Igg ◽  
Vectored Vaccine ◽  
Sera Samples

Abstract Limited data are available on the responses to heterologous vaccine regimens for SARS-CoV-2, especially among countries using inactivated and adenoviral-vectored vaccines. A total of 77 participants who received heterologous prime/booster-inactivated COVID-19 vaccine and adenoviral-vectored vaccine were enrolled in our study. There were two comparison groups vaccinated with the homologous CoronaVac (N = 79) and AZD1222 (N = 80) regimen. All sera samples were tested for SARS-CoV-2 spike receptor-binding-domain (RBD) IgG using a chemiluminescent microparticle immunoassay (CMIA). The neutralizing activity in a subset of serum samples was tested against the original Wuhan strain and variants of concern, B.1.1.7 and B.1.351, using an enzyme-linked immunosorbent assay (ELISA)-based surrogate virus neutralization test (sVNT). The CoronaVac followed by the AZD1222 vaccine induced higher levels of spike RBD-specific IgG than that of two-dose CoronaVac or AZD1222 vaccines (p < 0.001). Sera samples of the CoronaVac/AZD1222 vaccine recipients elicited higher neutralizing antibody activity against the original Wuhan and the B.1.351 strain than in the recipients of the two-dose CoronaVac or AZD1222. Following the inactivated CoronaVac/adenoviral-vectored (AZD1222) vaccination administered 14–72 days apart, participants receiving the heterologous vaccine regimen had higher spike RBD-specific IgG and neutralizing activities than the homologous CoronaVac vaccine recipients.

scholarly journals Assignment of Weight-Based Antibody Units for Seven Additional Serotypes to a Human Pneumococcal Standard Reference Serum, 007sp

2015 ◽  
Vol 22 (11) ◽  
pp. 1154-1159 ◽  
Author(s):  
D. Goldblatt ◽  
C. Y. Tan ◽  
P. Burbidge ◽  
S. McElhiney ◽  
L. McLaughlin ◽  
...  
Keyword(s):  
Polysaccharide Vaccine ◽  
Enzyme Linked Immunosorbent Assay ◽  
Reference Standard ◽  
Concordance Correlation ◽  
Clinical Protocol ◽  
Serum Samples ◽  
Reference Serum ◽  
Specific Igg ◽  
Standard Serum ◽  
Adult Volunteers

ABSTRACTThe pneumococcal enzyme-linked immunosorbent assay (ELISA) reference standard serum, lot 89SF, has been in use since 1990 and was replaced in 2013 with a new reference standard, 007sp, that is projected to be available for the next 25 years. 007sp was generated under an FDA-approved clinical protocol; 278 adult volunteers were immunized with the 23-valent unconjugated polysaccharide vaccine Pneumovax II, and a unit of blood was obtained twice from each immunized subject within 120 days following immunization. Pooled serum was prepared from the plasma of 262 subjects, filled at 6 ml per vial, and lyophilized. Five independent laboratories participated in bridging the serotype-specific IgG assignments for 89SF to the new reference standard, 007sp, to establish equivalent reference values for 13 pneumococcal capsular serotypes (1,3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19A, 19F, and 23F) by using the WHO reference ELISA. In a second study involving three laboratories, a similar protocol was used to assign weight-based IgG concentrations in micrograms per ml to 007sp of seven serotypes (8, 10A, 11A, 12F, 15B, 22F, and 33F) also present in the 23-valent pneumococcal unconjugated polysaccharide vaccine. In addition, the IgG assignments for a 12-member WHO quality control (QC) serum panel were also extended to cover these seven serotypes. Agreement was excellent, with a concordance correlation coefficient (rc) of >0.996 when each laboratory was compared to the assigned values for the 12 WHO QC serum samples. There are four remaining pneumococcal serotypes (2, 9N, 17F, and 20) found in Pneumovax II for which IgG assignments exist for 89SF and remain to be bridged.

Angiostrongylus costaricensis egg antigen for the immunodiagnosis of abdominal angiostrongyliasis

2008 ◽  
Vol 82 (3) ◽  
pp. 251-254 ◽  
Author(s):  
P. Mesén-Ramírez ◽  
E. Abrahams-Sandí ◽  
K. Fernández-Quesada ◽  
P. Morera
Keyword(s):  
The United States ◽  
Enzyme Linked Immunosorbent Assay ◽  
Histopathological Diagnosis ◽  
Parasitic Disease ◽  
Serum Samples ◽  
Widespread Occurrence ◽  
Specific Igg ◽  
Egg Antigen ◽  
Specific Diagnostic Test

AbstractAngiostrongylus costaricensis is the aetiological agent of human abdominal angiostrongyliasis, a parasitic disease reported from the United States to Argentina, with a widespread occurrence of the nematode throughout Central and South America. This study assesses the performance of A. costaricensis eggs as antigen in an enzyme-linked immunosorbent assay (ELISA), for the determination of parasite-specific IgG1 antibodies. The specificity and the sensitivity of the method were 87% and 90.5%, respectively. Through this test it was possible to demonstrate a sharp and early decline in IgG1 antibody in serum samples taken from patients with histopathological diagnosis of abdominal angiostrongyliasis at different time points after surgical treatment. The present work demonstrated the usefulness of the egg antigen in the development of a specific diagnostic test for abdominal angiostrongylosis.

Use of larval, parasitic female and egg antigens fromStrongyloides venezuelensisto detect parasite-specific IgG and immune complexes in immunodiagnosis of human strongyloidiasis

Parasitology ◽  
2012 ◽  
Vol 139 (7) ◽  
pp. 956-961 ◽  
Author(s):  
A. L. R. GONÇALVES ◽  
D. S. NUNES ◽  
M. R. F. GONÇALVES-PIRES ◽  
M. T. UETA ◽  
J. M. COSTA-CRUZ
Keyword(s):  
Immune Complex ◽  
Immune Complexes ◽  
Enzyme Linked Immunosorbent Assay ◽  
Diagnostic Efficiency ◽  
Serum Samples ◽  
Parasitic Female ◽  
Strongyloides Venezuelensis ◽  
Complex Detection ◽  
Specific Igg ◽  
Sensitivity Specificity

SUMMARYThe aim of this study was to use larval, parasitic female and egg antigens fromStrongyloides venezuelensisto detect parasite-specific IgG and immune complexes in human serum samples by enzyme-linked immunosorbent assay (ELISA). In total, 95 serum samples were analysed, consisting of 30 patients harbouringS. stercoralislarvae, 30 healthy subjects and 35 patients with other parasites. Sensitivity, specificity and diagnostic efficiency were calculated. A significant statistical difference was found in the detection of immune complexes and antibodies in patients harbouringS. stercoralislarvae from larval and eggs antigens, with higher positivity using larval antigen. The larval antigen showed the highest values for sensitivity, specificity and diagnostic efficiency in ELISA from detection of immune complexes. For the first time we used IgG anti-larvae, IgG anti-parasitic females or IgG anti-eggs for immune complex detection. We concluded that the association of antibody and immune complex detection could be used in the diagnosis of human strongyloidiasis.

scholarly journals Comparison of the Serum Neutralization Test and a Competitive Enzyme-Linked Immunosorbent Assay for the Detection of Antibodies to Vesicular Stomatitis Virus New Jersey and Vesicular Stomatitis Virus Indiana

2002 ◽  
Vol 14 (3) ◽  
pp. 240-242 ◽  
Author(s):  
Juan Francisco Alvarado ◽  
Gaby Dolz ◽  
Marco V. Herrero ◽  
Brian McCluskey ◽  
Mo Salman
Keyword(s):  
New Jersey ◽  
Confidence Interval ◽  
Vesicular Stomatitis Virus ◽  
Immunosorbent Assay ◽  
Neutralization Test ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Serum Neutralization ◽  
Serum Neutralization Test ◽  
Vesicular Stomatitis

A competitive enzyme-linked immunosorbent assay (C-ELISA) for the detection of antibodies against vesicular stomatitis virus New Jersey (VSV-NJ) and vesicular stomatitis virus Indiana (VSV-IN) was compared with the serum neutralization test (SNT) using 1,106 serum samples obtained from dairy cattle on sentinel study farms in the Poás region of Costa Rica. Kappa coefficients between the C-ELISA and the SNT were 0.8871 (95% confidence interval [CI]: 0.8587–0.9155) and 0.6912 (95% CI: 0.6246–0.7577) for the VSV-NJ and VSV-IN tests, respectively. These results indicate good to excellent agreement between the 2 tests under these conditions.

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