scholarly journals Quantification of SARS-CoV-2 neutralizing antibody by a pseudotyped virus based assay

2020 ◽  
Author(s):  
Jianhui Nie ◽  
Qianqian Li ◽  
Jiajing Wu ◽  
Chenyan Zhao ◽  
Huan Hao ◽  
...  
Keyword(s):  
Small Molecules ◽  
Neutralizing Antibody ◽  
Neutralization Assay ◽  
Pseudotyped Virus ◽  
Serum Samples ◽  
Virus Stock ◽  
Virus Attachment ◽  
Fusion Inhibitors ◽  
Level 2 ◽  
Biosafety Level

Abstract Jianhui Nie, Qianqian Li, and Jiajing Wu contributed equally to this work.Pseudotyped viruses are useful virological tools due to their safety and versatility. Based on a VSV pseudotyped virus production system, we developed a pseudotyped virus-based neutralization assay against SARS-CoV-2 in biosafety level 2 facilities. This protocol includes production, titration of the SARS-CoV-2 S pseudotyped virus and neutralization assay based on it. Various types of samples targeting virus attachment and entry could be evaluated for their potency, including serum samples derived from animals and humans, monoclonal antibodies, fusion inhibitors (peptides or small molecules). If the pseudotyped virus stock has been prepared in advance, it will take 2 days to get the potency data for the candidate samples. Experience of handling cells is needed before implementing this protocol.

scholarly journals Use of a Surrogate Chimeric Virus To Detect West Nile Virus-Neutralizing Antibodies in Avian and Equine Sera

2008 ◽  
Vol 16 (1) ◽  
pp. 134-135 ◽  
Author(s):  
Nicholas Komar ◽  
Stanley Langevin ◽  
Thomas P. Monath
Keyword(s):  
West Nile Virus ◽  
Neutralizing Antibodies ◽  
Yellow Fever Virus ◽  
Neutralizing Antibody ◽  
Serum Samples ◽  
West Nile ◽  
Virus West Nile ◽  
Antibody Titers ◽  
Level 2 ◽  
Biosafety Level

ABSTRACT A chimeric yellow fever virus/West Nile virus (WNV) was compared to WNV alone as a biosafety level 2 reagent in the plaque reduction neutralization test for determining WNV infection histories. Concordance was 96.3% among 188 avian and equine serum samples. Neutralizing antibody titers were frequently more than twofold lower with the chimera.

scholarly journals Kinetics of Neutralizing Antibody Response Underscores Clinical COVID-19 Progression

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Qing Lei ◽  
Hongyan Hou ◽  
Caizheng Yu ◽  
Yandi Zhang ◽  
Jo-Lewis Banga Ndzouboukou ◽  
...  
Keyword(s):  
Viral Infections ◽  
Onset Time ◽  
Neutralizing Antibody ◽  
Neutralization Assay ◽  
Multiple Organ ◽  
Pseudotyped Virus ◽  
Serum Samples ◽  
Virus Neutralization Assay ◽  
Effective Interventions

Background. Neutralizing antibody (nAb) response is generated following infection or immunization and plays an important role in the protection against a broad of viral infections. The role of nAb during clinical progression of coronavirus disease 2019 (COVID-19) remains little known. Methods. 123 COVID-19 patients during hospitalization in Tongji Hospital were involved in this retrospective study. The patients were grouped based on the severity and outcome. The nAb responses of 194 serum samples were collected from these patients within an investigation period of 60 days after the onset of symptoms and detected by a pseudotyped virus neutralization assay. The detail data about onset time, disease severity and laboratory biomarkers, treatment, and clinical outcome of these participants were obtained from electronic medical records. The relationship of longitudinal nAb changes with each clinical data was further assessed. Results. The nAb response in COVID-19 patients evidently experienced three consecutive stages, namely, rising, stationary, and declining periods. Patients with different severity and outcome showed differential dynamics of the nAb response over the course of disease. During the stationary phase (from 20 to 40 days after symptoms onset), all patients evolved nAb responses. In particular, high levels of nAb were elicited in severe and critical patients and older patients (≥60 years old). More importantly, critical but deceased COVID-19 patients showed high levels of several proinflammation cytokines, such as IL-2R, IL-8, and IL-6, and anti-inflammatory cytokine IL-10 in vivo, which resulted in lymphopenia, multiple organ failure, and the rapidly decreased nAb response. Conclusion. Our results indicate that nAb plays a crucial role in preventing the progression and deterioration of COVID-19, which has important implications for improving clinical management and developing effective interventions.

scholarly journals Delayed neutralizing antibody response in the acute phase correlates with severe progression of COVID-19

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hitoshi Kawasuji ◽  
Yoshitomo Morinaga ◽  
Hideki Tani ◽  
Miyuki Kimura ◽  
Hiroshi Yamada ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Neutralization Test ◽  
Neutralizing Antibody ◽  
Pseudotyped Virus ◽  
Serum Samples ◽  
Neutralization Activity ◽  
Neutralizing Activity ◽  
Time Points ◽  
Moderate Disease ◽  
Activity Dynamics

AbstractAdaptive immunity to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) dynamics remain largely unknown. The neutralizing antibody (NAb) levels in patients with coronavirus disease 2019 (COVID-19) are helpful for understanding the pathology. Using SARS-CoV-2 pseudotyped virus, serum sample neutralization values in symptomatic COVID-19 patients were measured using the chemiluminescence reduction neutralization test (CRNT). At least two sequential serum samples collected during hospitalization were analyzed to assess NAbs neutralizing activity dynamics at different time points. Of the 11 patients, four (36.4%), six (54.5%), and one (9.1%) had moderate, severe, and critical disease, respectively. Fifty percent neutralization (N50%-CRNT) was observed upon admission in 90.9% (10/11); all patients acquired neutralizing activity 2–12 days after onset. In patients with moderate disease, neutralization was observed at earliest within two days after symptom onset. In patients with severe-to-critical disease, neutralization activity increased, plateauing 9–16 days after onset. Neutralization activity on admission was significantly higher in patients with moderate disease than in patients with severe-to-critical disease (relative % of infectivity, 6.4% vs. 41.1%; P = .011). Neutralization activity on admission inversely correlated with disease severity. The rapid NAb response may play a crucial role in preventing the progression of COVID-19.

scholarly journals Neutralizing antibody and soluble ACE2 inhibition of a replication-competent VSV-SARS-CoV-2 and a clinical isolate of SARS-CoV-2

2020 ◽  
Author(s):  
James Brett Case ◽  
Paul W. Rothlauf ◽  
Rita E. Chen ◽  
Zhuoming Liu ◽  
Haiyan Zhao ◽  
...  
Keyword(s):  
Clinical Isolate ◽  
Neutralizing Antibodies ◽  
Neutralizing Antibody ◽  
Neutralization Assay ◽  
Spike Protein ◽  
Glycoprotein Gene ◽  
Level 3 ◽  
Focus Reduction ◽  
High Throughput Imaging ◽  
Biosafety Level

ABSTRACTAntibody-based interventions against SARS-CoV-2 could limit morbidity, mortality, and possibly disrupt epidemic transmission. An anticipated correlate of such countermeasures is the level of neutralizing antibodies against the SARS-CoV-2 spike protein, yet there is no consensus as to which assay should be used for such measurements. Using an infectious molecular clone of vesicular stomatitis virus (VSV) that expresses eGFP as a marker of infection, we replaced the glycoprotein gene (G) with the spike protein of SARS-CoV-2 (VSV-eGFP-SARS-CoV-2) and developed a high-throughput imaging-based neutralization assay at biosafety level 2. We also developed a focus reduction neutralization test with a clinical isolate of SARS-CoV-2 at biosafety level 3. We compared the neutralizing activities of monoclonal and polyclonal antibody preparations, as well as ACE2-Fc soluble decoy protein in both assays and find an exceptionally high degree of concordance. The two assays will help define correlates of protection for antibody-based countermeasures including therapeutic antibodies, immune γ-globulin or plasma preparations, and vaccines against SARS-CoV-2. Replication-competent VSV-eGFP-SARS-CoV-2 provides a rapid assay for testing inhibitors of SARS-CoV-2 mediated entry that can be performed in 7.5 hours under reduced biosafety containment.

scholarly journals Effective inactivation of nipah virus in serum samples for safe processing in low-containment laboratories

2020 ◽  
Author(s):  
Shumpei Watanabe ◽  
Shuetsu Fukushi ◽  
Toshihiko Harada ◽  
Masayuki Shimojima ◽  
Tomoki Yoshikawa ◽  
...  
Keyword(s):  
Nipah Virus ◽  
Aluminum Foil ◽  
Viral Disease ◽  
Serological Testing ◽  
Serum Samples ◽  
Optimized Protocol ◽  
History Of ◽  
Level 2 ◽  
Biosafety Level ◽  
Local Laboratory

Abstract Background Nipah virus (NiV) is an emerging zoonotic paramyxovirus that causes severe encephalitis and respiratory disease with a high mortality rate in humans. During large outbreaks of the viral disease, serological testing of serum samples could be a useful diagnostic tool, which could provide information on not only the diagnosis of NiV disease but also the history of an individual with previous exposure to the virus, thereby supporting disease control. Therefore, an efficient method for the inactivation of NiV in serum samples is required for serological diagnosis. Methods We determined the optimal conditions for the inactivation of NiV infectivity in human serum using heating and UV treatment. The inactivation method comprised UV irradiation with a cover of aluminum foil for 30 min and heating at 56 °C for 30 min. Results With an optimized protocol for virus inactivation, NiV infectivity in serum samples (containing 6.4 × 105 TCID50) was completely inactivated. Conclusions We developed a recommended protocol for the effective inactivation of NiV. This protocol would enable a regional or local laboratory to safely transport or process samples, including NiV, for serological testing in its biosafety level-2 facility.

scholarly journals Effective inactivation of Nipah virus in serum samples for safe processing in low-containment laboratories

2020 ◽  
Author(s):  
Shumpei Watanabe ◽  
Shuetsu Fukushi ◽  
Toshihiko Harada ◽  
Masayuki Shimojima ◽  
Tomoki Yoshikawa ◽  
...  
Keyword(s):  
Nipah Virus ◽  
Aluminum Foil ◽  
Viral Disease ◽  
Serological Testing ◽  
Serum Samples ◽  
Optimized Protocol ◽  
History Of ◽  
Level 2 ◽  
Biosafety Level ◽  
Local Laboratory

Abstract Background: Nipah virus (NiV) is an emerging zoonotic paramyxovirus that causes severe encephalitis and respiratory disease with a high mortality rate in humans. During large outbreaks of the viral disease, serological testing of serum samples could be a useful diagnostic tool, which could provide information on not only the diagnosis of NiV disease but also the history of an individual with previous exposure to the virus, thereby supporting disease control. Therefore, an efficient method for the inactivation of NiV in serum samples is required for serological diagnosis. Methods: We determined the optimal conditions for the inactivation of NiV infectivity in human serum using heating and UV treatment. The inactivation method comprised UV irradiation with a cover of aluminum foil for 30 min and heating at 56°C for 30 min. Results: With an optimized protocol for virus inactivation, NiV infectivity in serum samples (containing 6.0 ×10 5 TCID 50 ) was completely inactivated. Conclusions: We developed a recommended protocol for the effective inactivation of NiV. This protocol would enable a regional or local laboratory to safely transport or process samples, including NiV, for serological testing in its biosafety level-2 facility.

scholarly journals Inference of SARS-CoV-2 spike-binding neutralizing antibody titers in sera from hospitalized COVID-19 patients by using commercial enzyme and chemiluminescent immunoassays

2020 ◽  
Author(s):  
Arantxa Valdivia ◽  
Ignacio Torres ◽  
Victor Latorre ◽  
Carla Frances-Gomez ◽  
Eliseo Albert ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Neutralizing Antibody ◽  
Neutralization Assay ◽  
Virus Neutralization ◽  
Pseudotyped Virus ◽  
S Protein ◽  
Neutralizing Activity ◽  
Virus Neutralization Assay ◽  
Degree Correlation ◽  
Antibody Titers

Background: Whether antibody levels measured by commercially-available enzyme or chemiluminescent immunoassays targeting the SARS-CoV-2 spike (S) protein can act as a proxy for serum neutralizing activity remains to be established for many of these assays. Objectives: To evaluate the degree of correlation between neutralizing antibodies (NtAb) binding the SARS-CoV-2 Spike (S) protein and SARS-CoV-2-S-IgG levels measured by four commercial immunoassays in sera drawn from hospitalized COVID-19 patients. Patients and Methods: Ninety sera from 51 hospitalized COVID-19 patients were assayed by a pseudotyped virus neutralization assay, the LIAISON SARS-CoV-2 S1/S2 IgG, the Euroimmun SARS-CoV-2 IgG ELISA, the MAGLUMI 2019-nCoV IgG and the COVID-19 ELISA IgG assays. Results: Overall, the results obtained with the COVID-19 ELISA IgG test showed the highest agreement with the NtAb assay (κ, 0.85; 95% CI, 0.63-1). The most sensitive tests were the pseudotyped virus NtAb assay and the COVID-19 ELISA IgG assay (92.2% for both). Overall, the degree correlation between antibody titers resulting in 50% virus neutralization (NtAb50) in the pseudotyped virus assay and SARS-CoV-2 IgG levels was strong for the Euroimmun SARS-CoV-2 IgG ELISA (Rho=0.73) and moderate for the remaining assays (Rho=0.48 to 0.59). The kinetic profile of serum NtAb50 titers could not be reliably predicted by any of the SARS-CoV-2 IgG immunoassays. Conclusions: the suitability of SARS-CoV-2-S-IgG commercial immunoassays for inferring neutralizing activity of sera from hospitalized COVID-19 patients varies widely across tests and is influenced by the time of sera collection after the onset of symptoms.

scholarly journals Variable loss of antibody potency against SARS-CoV-2 B.1.1.529 (Omicron)

2021 ◽  
Author(s):  
Daniel J. Sheward ◽  
Changil Kim ◽  
Roy A. Ehling ◽  
Alec Pankow ◽  
Xaquin Castro Dopico ◽  
...  
Keyword(s):  
Healthcare Workers ◽  
Blood Donors ◽  
Neutralizing Antibody ◽  
Neutralization Assay ◽  
Antibody Responses ◽  
Pseudotyped Virus ◽  
Virus Neutralization Assay ◽  
Form Part ◽  
Antibody Titers ◽  
Cross Neutralization

The recently-emerged SARS-CoV-2 B.1.1.529 variant (Omicron) is spreading rapidly in many countries, with a spike that is highly diverged from the pandemic founder, raising fears that it may evade neutralizing antibody responses. We cloned the Omicron spike from a diagnostic sample which allowed us to rapidly establish an Omicron pseudotyped virus neutralization assay, sharing initial neutralization results only 13 days after the variant was first reported to the WHO, 8 days after receiving the sample. Here we show that Omicron is substantially resistant to neutralization by several monoclonal antibodies that form part of clinical cocktails. Further, we find neutralizing antibody responses in pooled reference sera sampled shortly after infection or vaccination are substantially less potent against Omicron, with neutralizing antibody titers reduced by up to 45 fold compared to those for the pandemic founder. Similarly, in a cohort of convalescent sera prior to vaccination, neutralization of Omicron was low to undetectable. However, in recent samples from two cohorts from Stockholm, Sweden, antibody responses capable of cross-neutralizing Omicron were prevalent. Sera from infected-then-vaccinated healthcare workers exhibited robust cross-neutralization of Omicron, with an average potency reduction of only 5-fold relative to the pandemic founder variant, and some donors showing no loss at all. A similar pattern was observed in randomly sampled recent blood donors, with an average 7-fold loss of potency. Both cohorts showed substantial between-donor heterogeneity in their ability to neutralize Omicron. Together, these data highlight the extensive but incomplete evasion of neutralizing antibody responses by the Omicron variant, and suggest that increasing the magnitude of neutralizing antibody responses by boosting with unmodified vaccines may suffice to raise titers to levels that are protective.

scholarly journals Choosing the right tool for the job: A comprehensive assessment of serological assays for SARS-CoV-2 as surrogates for authentic virus neutralization

2021 ◽  
Author(s):  
Nicholas Wohlgemuth ◽  
Kendall Whitt ◽  
Sean Cherry ◽  
Ericka Kirkpatrick Roubidoux ◽  
Chun-Yang Lin ◽  
...  
Keyword(s):  
Neutralizing Antibody ◽  
Virus Neutralization ◽  
Diagnostic Tools ◽  
Pseudotyped Virus ◽  
Global Pandemic ◽  
Level 3 ◽  
The Right ◽  
Antibody Levels ◽  
Reliable Methods ◽  
Biosafety Level

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in late 2019 and has since caused a global pandemic resulting in millions of cases and deaths. Diagnostic tools and serological assays are critical for controlling the outbreak, especially assays designed to quantitate neutralizing antibody levels, considered the best correlate of protection. As vaccines become increasingly available, it is important to identify reliable methods for measuring neutralizing antibody responses that correlate with authentic virus neutralization but can be performed outside of biosafety level 3 (BSL3) laboratories. While many neutralizing assays using pseudotyped virus have been developed, there have been few studies comparing the different assays to each other as surrogates for authentic virus neutralization. Here we characterized three enzyme-linked immunosorbent assays (ELISAs) and three pseudotyped VSV virus neutralization assays and assessed their concordance with authentic virus neutralization. The most accurate assays for predicting authentic virus neutralization were luciferase and secreted embryonic alkaline phosphatase (SEAP) expressing pseudotyped virus neutralizations, followed by GFP expressing pseudotyped virus neutralization, and then the ELISAs.

scholarly journals SARS-CoV-2 Serum Neutralization Assay: A Traditional Tool for a Brand-New Virus

Viruses ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 655
Author(s):  
Giulia Matusali ◽  
Francesca Colavita ◽  
Daniele Lapa ◽  
Silvia Meschi ◽  
Licia Bordi ◽  
...  
Keyword(s):  
Neutralizing Antibody ◽  
Neutralization Assay ◽  
Serum Samples ◽  
Roc Curve Analysis ◽  
Routine Testing ◽  
Serum Neutralization ◽  
Testing Algorithms ◽  
Set Up ◽  
Testing Algorithm ◽  
Microneutralization Test

SARS-CoV-2 serum neutralization assay represents the gold standard for assessing antibody-mediated protection in naturally infected and vaccinated individuals. In the present study, 662 serum samples collected from February 2020 to January 2021 from acute and convalescent COVID-19 patients were tested to determine neutralizing antibody (NAb) titers using a microneutralization test (MNT) for live SARS-CoV-2. Moreover, anti-SARS-CoV-2 IgG, IgA, and IgM directed against different viral antigens were measured by high-throughput automated platforms. We observed higher levels of NAbs in elderly (>60 years old) individuals and in patients presenting acute respiratory distress syndrome. SARS-CoV-2 NAbs develop as soon as five days from symptom onset and, despite a decline after the second month, persist for over 11 months, showing variable dynamics. Through correlation and receiver operating characteristic (ROC) curve analysis, we set up a testing algorithm, suitable for the laboratory workload, by establishing an optimal cutoff value of anti-SARS-CoV-2 IgG for convalescent plasma donors to exclude from MNT samples foreseen to have low/negative NAb titers and ineligible for plasma donation. Overall, MNT, although cumbersome and not suitable for routine testing of large sample sizes, remains the reference tool for the assessment of antibody-mediated immunity after SARS-CoV-2 infection. Smart testing algorithms may optimize the laboratory workflow to monitor antibody-mediated protection in COVID-19 patients, plasma donors, and vaccinated individuals.

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