scholarly journals Waning antibody levels after vaccination with mRNA BNT162b2 and inactivated CoronaVac COVID-19 vaccines in Hong Kong blood donors

2021 ◽  
Author(s):  
Shirley LL Kwok ◽  
Samuel MS Cheng ◽  
Jennifer NS Leung ◽  
Kathy Leung ◽  
Cheuk-Kwong Lee ◽  
...  
Keyword(s):  
Hong Kong ◽  
Vaccination Programme ◽  
Blood Donors ◽  
Neutralization Test ◽  
Virus Neutralization Test ◽  
Virus Neutralization ◽  
Inactivated Vaccine ◽  
Immunosorbent Assays ◽  
Antibody Levels

AbstractBoth inactivated vaccine (CoronaVac; Sinovac) and mRNA vaccine (Comirnaty/BNT162b2; Fosun-Pharma/BioNTech) are available in Hong Kong’s COVID-19 Vaccination Programme. We reported waning antibody levels by enzyme-linked immunosorbent assays (ELISA) and surrogate virus neutralization test (sVNT) among 850 fully vaccinated blood donors (i.e., received two doses). The BNT162b2 group’s antibody levels remain over the 50% protection threshold within six months, and the CoronaVac’s group’s median antibody levels begin to fall below the 50% protection threshold two months after vaccination.

scholarly journals Waning antibody levels after COVID-19 vaccination with mRNA Comirnaty and inactivated CoronaVac vaccines in blood donors, Hong Kong, April 2020 to October 2021

2022 ◽  
Vol 27 (2) ◽  
Author(s):  
Shirley LL Kwok ◽  
Samuel MS Cheng ◽  
Jennifer NS Leung ◽  
Kathy Leung ◽  
Cheuk-Kwong Lee ◽  
...  
Keyword(s):  
Hong Kong ◽  
Vaccination Programme ◽  
Blood Donors ◽  
Inactivated Vaccine ◽  
Antibody Levels

The mRNA vaccine Comirnaty and the inactivated vaccine CoronaVac are both available in Hong Kong’s COVID-19 vaccination programme. We observed waning antibody levels in 850 fully vaccinated (at least 14 days passed after second dose) blood donors using ELISA and surrogate virus neutralisation test. The Comirnaty-vaccinated group’s (n = 593) antibody levels remained over the ELISA and sVNT positive cut-offs within the first 6 months. The CoronaVac-vaccinated group’s (n = 257) median antibody levels began to fall below the cut-offs 4 months after vaccination.

scholarly journals Quantitative SARS-CoV-2 Spike Antibody Response in COVID-19 Patients Using Three Fully Automated Immunoassays and a Surrogate Virus Neutralization Test

Diagnostics ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1496
Author(s):  
Yoonjoo Kim ◽  
Ji Hyun Lee ◽  
Geon Young Ko ◽  
Ji Hyeong Ryu ◽  
Joo Hee Jang ◽  
...  
Keyword(s):  
Time Course ◽  
Neutralization Test ◽  
Severe Disease ◽  
Area Under The Curve ◽  
Virus Neutralization Test ◽  
Virus Neutralization ◽  
S Protein ◽  
Antibody Assays ◽  
Sequential Samples ◽  
Antibody Levels

Quantitative SARS-CoV-2 antibody assays against the spike (S) protein are useful for monitoring immune response after infection or vaccination. We compared the results of three chemiluminescent immunoassays (CLIAs) (Abbott, Roche, Siemens) and a surrogate virus neutralization test (sVNT, GenScript) using 191 sequential samples from 32 COVID-19 patients. All assays detected >90% of samples collected 14 days after symptom onset (Abbott 97.4%, Roche 96.2%, Siemens 92.3%, and GenScript 96.2%), and overall agreement among the four assays was 91.1% to 96.3%. When we assessed time-course antibody levels, the Abbott and Siemens assays showed higher levels in patients with severe disease (p < 0.05). Antibody levels from the three CLIAs were correlated (r = 0.763–0.885). However, Passing–Bablok regression analysis showed significant proportional differences between assays and converting results to binding antibody units (BAU)/mL still showed substantial bias. CLIAs had good performance in predicting sVNT positivity (Area Under the Curve (AUC), 0.959–0.987), with Abbott having the highest AUC value (p < 0.05). SARS-CoV-2 S protein antibody levels as assessed by the CLIAs were not interchangeable, but showed reliable performance for predicting sVNT results. Further standardization and harmonization of immunoassays might be helpful in monitoring immune status after COVID-19 infection or vaccination.

scholarly journals Evaluation of six commercial SARS-CoV-2 Enzyme-Linked Immunosorbent assays for clinical testing and serosurveillance

2021 ◽  
Author(s):  
Suellen Nicholson ◽  
Theo Karapanagiotidis ◽  
Arseniy Khvorov ◽  
Celia Douros ◽  
Francesca Mordant ◽  
...  
Keyword(s):  
Neutralization Test ◽  
Virus Neutralization Test ◽  
Virus Neutralization ◽  
Receptor Binding Domain ◽  
Neutralising Antibodies ◽  
Serological Tests ◽  
Patient Diagnosis ◽  
Pandemic Response ◽  
Immunosorbent Assays ◽  
Testing Algorithm

ABSTRACTBackgroundSerological testing for SARS-CoV-2 complements nucleic acid tests for patient diagnosis and enables monitoring of population susceptibility to inform the COVID-19 pandemic response. As we move into the era of vaccines, the detection of neutralising antibody will become increasingly important. Many serological tests have been developed under emergency use authorization, but their reliability remains unclear.MethodsWe evaluated the performance of six commercially-available Enzyme-linked Immunosorbent Assays (ELISAs), including a surrogate virus neutralization test, for detection of SARS-CoV-2 immunoglobulins (IgA, IgM, IgG), total or neutralising antibodies and a subset of results were compared to microneutralisation.ResultsFor sera collected > 14 days post-symptom onset the Wantai total Ab performed best with highest sensitivity 100% (95% confidence interval: 94.6-100) followed by 93.1% for Euroimmun NCP-IgG,93.1% for GenScript Surrogate Virus Neutralization Test, 90.3% for Euroimmun S1-IgG, 88.9% for Euroimmun S1-IgA and 83.3% for Wantai IgM. Specificity for the best performing assay was 99.5% and for the lowest 97.1%.ConclusionWantai ELISA, detecting total immunoglobulins against SARS-CoV-2 receptor binding domain, had the best performance. Antibody target, timing and longevity of the immune response, and the objectives of testing should be considered in test choice. ELISAs should be used within a confirmatory testing algorithm to ensure reliable results. ELISAs provide high quality results, with flexibility for test numbers without the need for manufacturer specific analyzers.

STUDIES ON PASSIVE IMMUNITY IN POLIOMYELITIS

1952 ◽  
Vol 30 (1) ◽  
pp. 54-67 ◽  
Author(s):  
A. J. Rhodes ◽  
Eina M. Clark ◽  
F. T. Shimada ◽  
W. L. Donohue ◽  
R. C. Ritchie ◽  
...  
Keyword(s):  
Rhesus Monkeys ◽  
Neutralization Test ◽  
Immune Serum ◽  
Virus Neutralization Test ◽  
Virus Neutralization ◽  
Passive Immunity ◽  
Intramuscular Route ◽  
Paraffin Oil ◽  
Rest Periods ◽  
Antibody Levels

Thirty rhesus monkeys have been repeatedly injected with Lansing polio-myelitis virus by the intramuscular route. Antibody, as measured by a virus-neutralization test in mice, rapidly developed in the serum. About 3 liters of immune serum with a 50% neutralizing titer of 10−3.0 or higher were collected with a view to fractionation. Antibody levels tended to be maintained during rest periods when no injections were given. The evidence suggests that, on the whole, antibody levels were higher in animals receiving virus incorporated in paraffin oil adjuvant than in those receiving virus suspended in water. Certain individual monkeys receiving virus in water responded as well, however, as monkeys receiving virus in adjuvant.

scholarly journals Five Commercial Immunoassays for SARS-CoV-2 Antibody Determination and Their Comparison and Correlation with the Virus Neutralization Test

Diagnostics ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 593
Author(s):  
Václav Šimánek ◽  
Ladislav Pecen ◽  
Zuzana Krátká ◽  
Tomáš Fürst ◽  
Hana Řezáčková ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Neutralization Test ◽  
Young Patients ◽  
Virus Neutralization Test ◽  
Virus Neutralization ◽  
Age Dependent ◽  
Previous Contact ◽  
Dependent Elderly ◽  
Protein Assays ◽  
Antibody Determination

There is an ongoing debate as to whether SARS-CoV-2 antibodies can be found in patients who have recovered from COVID-19 disease. Currently, there is no consensus on whether the antibodies, if present, are protective. Our regular measurements of SARS-CoV-2 antibodies, starting in July 2020, have provided us with the opportunity of becoming acquainted with the five different immunoassays. A total of 149 patients were enrolled in our study. We measured the samples using each immunoassay, then performing a virus neutralization test and comparing the results of SARS-CoV-2 antibodies with this test. We observed that the production of neutralizing antibodies is age-dependent. Elderly patients have a higher proportion of high neutralizing titers than young patients. Based on our results, and in combination with the literature findings, we can conclude that the serological SARS-CoV-2 antibody measurement is a helpful tool in the fight against COVID-19. The assays can provide information about the patient’s previous contact with the virus. Anti-spike protein assays correlate well with the virus neutralization test and can be used in the screening of potential convalescent plasma donors.

scholarly journals Evaluation of six commercial SARS-CoV-2 serology assays detecting different antibodies for clinical testing and serosurveillance

2021 ◽  
Author(s):  
Suellen Nicholson ◽  
Theo Karapanagiotidis ◽  
Arseniy Khvorov ◽  
Celia Douros ◽  
Francesca Mordant ◽  
...  
Keyword(s):  
Cell Culture ◽  
Neutralization Test ◽  
Serological Test ◽  
Neutralizing Antibody ◽  
Neutralization Assay ◽  
Virus Neutralization Test ◽  
Virus Neutralization ◽  
Binding Assays ◽  
Humoral Immune ◽  
A Cell

Abstract Background Serological testing for SARS-CoV-2 complements nucleic acid tests for patient diagnosis and enables monitoring of population susceptibility to inform the COVID-19 pandemic response. It is important to understand the reliability of assays with different antigen or antibody targets to detect humoral immunity after SARS-CoV-2 infection and to understand how antibody (Ab) binding assays compare to those detecting neutralizing antibody (nAb), particularly as we move into the era of vaccines. Methods We evaluated the performance of six commercially available Enzyme-linked Immunosorbent Assays (ELISAs), including a surrogate virus neutralization test (sVNT), for detection of SARS-CoV-2 immunoglobulins (IgA, IgM, IgG), total or nAb. A result subset was compared to a cell culture-based microneutralisation (MN) assay. We tested sera from patients with prior RT-PCR confirmed SARS-CoV-2 infection, pre-pandemic sera and potential cross-reactive sera from patients with other non-COVID-19 acute infections. Results For sera collected &gt; 14 days post-symptom onset, the assay achieving the highest sensitivity was the Wantai total Ab at 100% (95% confidence interval: 94.6-100) followed by 93.1% for Euroimmun NCP-IgG, 93.1% for GenScript sVNT, 90.3% for Euroimmun S1-IgG, 88.9% for Euroimmun S1-IgA and 83.3% for Wantai IgM. Specificity for the best performing assay was 99.5% for the Wantai total Ab and for the lowest performing assay was 97.1% for sVNT (as per IFU). The Wantai Total Ab had the best agreement with MN at 98% followed by Euroimmun S1-IgA, Euro NCP-IgG and sVNT (as per IFU) with (97%, 97% and 95% respectively) and Wantai IgM having the poorest agreement at 93%. Conclusion Performance characteristics of the SARS-CoV-2 serology assays detecting different antibody types are consistent with those found in previously published reports. Evaluation of the surrogate virus neutralization test in comparison to the Ab binding assays and a cell culture-based neutralization assay showed good result correlation between all assays. However correlation between the cell-based neutralization test and some assays detecting Ab’s not specifically involved in neutralization was higher than with the sVNT. This study demonstrates the reliability of different assays to detect the humoral immune response following SARS-CoV-2 infection, which can be used to optimise serological test algorithms for assessing antibody responses post SARS-CoV-2 infection or vaccination.

POLIOMYELITIS IN CANADIAN ESKIMOS

1952 ◽  
Vol 30 (5) ◽  
pp. 390-402
Author(s):  
E. M. Clark ◽  
A. J. Rhodes
Keyword(s):  
World Wide ◽  
Neutralization Test ◽  
Virus Neutralization Test ◽  
Virus Neutralization ◽  
Baffin Island ◽  
Poliomyelitis Virus

Studies of the basic immunology of poliomyelitis in Canadian Eskimos have been continued. The sera of 24 Eskimos living at Lake Harbour and of 99 at Pangnirtung, Baffin Island, have been tested for poliomyelitis antibody by means of the Lansing virus neutralization test. Poliomyelitis occurred in Lake Harbour in 1943 but has not been recorded in Pangnirtung. Eighteen of the 24 sera from Lake Harbour contained antibody, but only 10 from the 99 Pangnirtung residents. The positive sera from Pangnirtung were all in persons aged 18 and over. These results are compared with those previously reported by the authors with the sera of Eskimos at Chesterfield Inlet, and with those reported by Paul with the sera of North Alaskan Eskimos. The evidence suggests that poliomyelitis virus is world-wide in distribution.

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