scholarly journals Neutralization against Omicron SARS-CoV-2 from previous non-Omicron infection

2021 ◽  
Author(s):  
jing Zou ◽  
Hongjie Xia ◽  
Xuping Xie ◽  
Chaitanya Kurhade ◽  
Rafael R. Machado ◽  
...  
Keyword(s):  
High Throughput ◽  
Post Infection ◽  
Health Impact ◽  
Neutralization Assay ◽  
Cross Protection ◽  
Spike Gene ◽  
Fold Reduction ◽  
Cross Neutralization ◽  
The Cross

The explosive spread of the Omicron SARS-CoV-2 variant underscores the importance of analyzing the cross-protection from previous non-Omicron infection. We developed a high-throughput neutralization assay for Omicron SARS-CoV-2 by engineering the Omicron spike gene into an mNeonGreen USA-WA1/2020 SARS-CoV-2 (isolated in January 2020). Using this assay, we determined the neutralization titers of patient sera collected at 1- or 6-months after infection with non-Omicron SARS-CoV-2. From 1- to 6-month post-infection, the neutralization titers against USA-WA1/2020 decreased from 601 to 142 (a 4.2-fold reduction), while the neutralization titers against Omicron-spike SARS-CoV-2 remained low at 38 and 32, respectively. Thus, at 1- and 6-months after non-Omicron SARS-CoV-2 infection, the neutralization titers against Omicron were 15.8- and 4.4-fold lower than those against USA-WA1/2020, respectively. The low cross-neutralization against Omicron from previous non-Omicron infection supports vaccination of formerly infected individuals to mitigate the health impact of the ongoing Omicron surge.

scholarly journals Correlates of Neutralization Against SARS-CoV-2 Variants of Concern by Early Pandemic Sera

2021 ◽  
Author(s):  
Samuel J. Vidal ◽  
Ai-ris Y. Collier ◽  
Jingyou Yu ◽  
Katherine McMahan ◽  
Lisa H. Tostanoski ◽  
...  
Keyword(s):  
Natural Infection ◽  
Neutralizing Antibody ◽  
Natural Immunity ◽  
Spike Gene ◽  
Cell Responses ◽  
Fold Reduction ◽  
Cross Neutralization ◽  
Protection Against Infection ◽  
Induced Immunity ◽  
Shed Light

Emerging SARS-CoV-2 variants of concern that overcome natural and vaccine-induced immunity threaten to exacerbate the COVID-19 pandemic. Increasing evidence suggests that neutralizing antibody (NAb) responses are a primary mechanism of protection against infection. However, little is known about the extent and mechanisms by which natural immunity acquired during the early COVID-19 pandemic confers cross-neutralization of emerging variants. In this study, we investigated cross-neutralization of the B.1.1.7 and B.1.351 SARS-CoV-2 variants in a well-characterized cohort of early pandemic convalescent subjects. We observed modestly decreased cross-neutralization of B.1.1.7 but a substantial 4.8-fold reduction in cross-neutralization of B.1.351. Correlates of cross-neutralization included receptor binding domain (RBD) and N-terminal domain (NTD) binding antibodies, homologous NAb titers, and Membrane-directed T cell responses. These data shed light on cross-neutralization of emerging variants by early pandemic convalescent immune responses. IMPORTANCE Widespread immunity to SARS-CoV-2 will be necessary to end the COVID-19 pandemic. Neutralizing antibody (NAb) responses are a critical component of immunity that can be stimulated by natural infection as well as vaccines. However, SARS-CoV-2 variants are emerging that contain mutations in the Spike gene that promote evasion from NAb responses. These variants may therefore delay control of the COVID-19 pandemic. We studied whether NAb responses from early COVID-19 convalescent patients are effective against the two SARS-CoV-2 variants B.1.1.7 and B.1.351. We observed that the B.1.351 variant demonstrates significantly reduced susceptibility to early pandemic NAb responses. We additionally characterized virologic, immunologic, and clinical features that correlate with cross-neutralization. These studies increase our understanding of emerging SARS-CoV-2 variants.

scholarly journals Evaluation of a Pseudovirus Neutralization Assay for SARS-CoV-2 and Correlation with Live Virus-Based Micro Neutralization Assay

Diagnostics ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 994
Author(s):  
Ahmed Majdi K. Tolah ◽  
Sayed S. Sohrab ◽  
Khaled Majdi K. Tolah ◽  
Ahmed M. Hassan ◽  
Sherif A. El-Kafrawy ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Epidemiological Studies ◽  
Neutralization Assay ◽  
Serum Samples ◽  
Live Virus ◽  
Spike Gene ◽  
Microneutralization Assay ◽  
Viral Particles ◽  
Reliable Performance ◽  
Prior Infection

The unusual cases of pneumonia outbreak were reported from Wuhan city in late December 2019. Serological testing provides a powerful tool for the identification of prior infection and for epidemiological studies. Pseudotype virus neutralization assays are widely used for many viruses and applications in the fields of serology. The accuracy of pseudotype neutralizing assay allows for its use in low biosafety lab and provides a safe and effective alternative to the use of wild-type viruses. In this study, we evaluated the performance of this assay compared to the standard microneutralization assay as a reference. The lentiviral pseudotype particles were generated harboring the Spike gene of SARS-CoV-2. The generated pseudotype particles assay was used to evaluate the activity of neutralizing antibodies in 300 human serum samples from a COVID-19 sero-epidemiological study. Testing of these samples resulted in 55 positive samples and 245 negative samples by pseudotype viral particles assay while microneutralization assay resulted in 64 positive and 236 negative by MN assay. Compared to the MN, the pseudotyped viral particles assay showed a sensitivity of 85.94% and a specificity of 100%. Based on the data generated from this study, the pseudotype-based neutralization assay showed a reliable performance for the detection of neutralizing antibodies against SARS-CoV-2 and can be used safely and efficiently as a diagnostic tool in a biosafety level 2 laboratory.

scholarly journals An Optimized High-Throughput Neutralization Assay for Hepatitis E Virus (HEV) Involving Detection of Secreted Porf2

Viruses ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 64 ◽  
Author(s):  
Chang Liu ◽  
Wei Cai ◽  
Xin Yin ◽  
Zimin Tang ◽  
Guiping Wen ◽  
...  
Keyword(s):  
High Throughput ◽  
Hepatitis E Virus ◽  
Hepatitis E ◽  
Neutralization Assay ◽  
The Novel ◽  
Specific Antibodies ◽  
Neutralizing Activity ◽  
Elisa Kit ◽  
Neutralizing Capacity ◽  
Potential Threshold

Hepatitis E virus (HEV) is a common cause of acute hepatitis worldwide. Current methods for evaluating the neutralizing activity of HEV-specific antibodies include immunofluorescence focus assays (IFAs) and real-time PCR, which are insensitive and operationally complicated. Here, we developed a high-throughput neutralization assay by measuring secreted pORF2 levels using an HEV antigen enzyme-linked immunosorbent assay (ELISA) kit based on the highly replicating HEV genotype (gt) 3 strain Kernow. We evaluated the neutralizing activity of HEV-specific antibodies and the sera of vaccinated individuals (n = 15) by traditional IFA and the novel assay simultaneously. A linear regression analysis shows that there is a high degree of correlation between the two assays. Furthermore, the anti-HEV IgG levels exhibited moderate correlation with the neutralizing titers of the sera of vaccinated individuals, indicating that immunization with gt 1 can protect against gt 3 Kernow infection. We then determined specificity of the novel assay and the potential threshold of neutralizing capacity using anti-HEV IgG positive sera (n = 27) and anti-HEV IgG negative sera (n = 23). The neutralizing capacity of anti-HEV IgG positive sera was significantly stronger than that of anti-HEV IgG negative. In addition, ROC curve analysis shows that the potential threshold of neutralizing capacity of sera was 8.07, and the sensitivity and specificity of the novel assay was 88.6% and 100%, respectively. Our results suggest that the neutralization assay using the antigen ELISA kit could be a useful tool for HEV clinical research.

Development of a high-throughput β-Gal-based neutralization assay for quantitation of herpes simplex virus-neutralizing antibodies in human samples

Vaccine ◽  
2016 ◽  
Vol 34 (33) ◽  
pp. 3901-3906 ◽  
Author(s):  
Amy Baccari ◽  
Michael Cooney ◽  
Tamara P. Blevins ◽  
Lynda A. Morrison ◽  
Shane Larson ◽  
...  
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
High Throughput ◽  
Neutralizing Antibodies ◽  
Neutralization Assay ◽  
Human Samples ◽  
Simplex Virus

scholarly journals High-throughput neutralization assay for multiple flaviviruses based on single-round infectious particles using dengue virus type 1 reporter replicon

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Mami Matsuda ◽  
Atsushi Yamanaka ◽  
Keigo Yato ◽  
Kentaro Yoshii ◽  
Koichi Watashi ◽  
...  
Keyword(s):  
Dengue Virus ◽  
Virus Type ◽  
High Throughput ◽  
Neutralization Assay

scholarly journals HiSpike Method for High-Throughput Cost Effective Sequencing of the SARS-CoV-2 Spike Gene

2022 ◽  
Vol 8 ◽  
Author(s):  
Ephraim Fass ◽  
Gal Zizelski Valenci ◽  
Mor Rubinstein ◽  
Paul J. Freidlin ◽  
Shira Rosencwaig ◽  
...  
Keyword(s):  
Real Time ◽  
High Throughput ◽  
Cost Effective ◽  
Developed Countries ◽  
Spike Protein ◽  
Medical Community ◽  
Effective Vaccine ◽  
Gene Variants ◽  
Spike Gene ◽  
Field Samples

The changing nature of the SARS-CoV-2 pandemic poses unprecedented challenges to the world's health systems. Emerging spike gene variants jeopardize global efforts to produce immunity and reduce morbidity and mortality. These challenges require effective real-time genomic surveillance solutions that the medical community can quickly adopt. The SARS-CoV-2 spike protein mediates host receptor recognition and entry into the cell and is susceptible to generation of variants with increased transmissibility and pathogenicity. The spike protein is the primary target of neutralizing antibodies in COVID-19 patients and the most common antigen for induction of effective vaccine immunity. Tight monitoring of spike protein gene variants is key to mitigating COVID-19 spread and generation of vaccine escape mutants. Currently, SARS-CoV-2 sequencing methods are labor intensive and expensive. When sequence demands are high sequencing resources are quickly exhausted. Consequently, most SARS-CoV-2 strains are sequenced in only a few developed countries and rarely in developing regions. This poses the risk that undetected, dangerous variants will emerge. In this work, we present HiSpike, a method for high-throughput cost effective targeted next generation sequencing of the spike gene. This simple three-step method can be completed in < 30 h, can sequence 10-fold more samples compared to conventional methods and at a fraction of their cost. HiSpike has been validated in Israel, and has identified multiple spike variants from real-time field samples including Alpha, Beta, Delta and the emerging Omicron variants. HiSpike provides affordable sequencing options to help laboratories conserve resources for widespread high-throughput, near real-time monitoring of spike gene variants.

scholarly journals Neutralization Assay Using a Modified Vaccinia Virus Ankara Vector Expressing the Green Fluorescent Protein Is a High-Throughput Method To Monitor the Humoral Immune Response against Vaccinia Virus

2004 ◽  
Vol 11 (2) ◽  
pp. 406-410 ◽  
Author(s):  
Antonio Cosma ◽  
Silja Bühler ◽  
Rashmi Nagaraj ◽  
Caroline Staib ◽  
Anna-Lena Hammarin ◽  
...  
Keyword(s):  
Immune Response ◽  
Green Fluorescent Protein ◽  
Vaccinia Virus ◽  
High Throughput ◽  
Neutralizing Antibodies ◽  
Fluorescent Protein ◽  
Safety Concern ◽  
Neutralization Assay ◽  
Modified Vaccinia Virus Ankara ◽  
Green Fluorescent

ABSTRACT Vaccination against smallpox is again considered in order to face a possible bioterrorist threat, but the nature and the level of the immune response needed to protect a person from smallpox after vaccination are not totally understood. Therefore, simple, rapid, and accurate assays to evaluate the immune response to vaccinia virus need to be developed. Neutralization assays are usually considered good predictors of vaccine efficacy and more informative with regard to protection than binding assays. Currently, the presence of neutralizing antibodies to vaccinia virus is measured using a plaque reduction neutralization test, but this method is time-consuming and labor-intensive and has a subjective readout. Here, we describe an innovative neutralization assay based on a modified vaccinia virus Ankara (MVA) vector expressing the green fluorescent protein (MVA-gfp). This MVA-gfp neutralization assay is rapid and sensitive and has a high-throughput potential. Thus, it is suitable to monitor the immune response and eventually the efficacy of a large campaign of vaccination against smallpox and to study the vector-specific immune response in clinical trials that use genetically engineered vaccinia viruses. Most importantly, application of the highly attenuated MVA eliminates the safety concern in using the replication-competent vaccinia virus in the standard clinical laboratory.

IL-33-ILC2 axis represents a potential adjuvant target to increase the cross-protective efficacy of influenza vaccine

2021 ◽  
Author(s):  
Clare M. Williams ◽  
Sreeja Roy ◽  
Danielle Califano ◽  
Andrew N. J. McKenzie ◽  
Dennis W. Metzger ◽  
...  
Keyword(s):  
Influenza Vaccine ◽  
Humoral Immunity ◽  
Vaccine Efficacy ◽  
Influenza Pandemic ◽  
Influenza Viruses ◽  
Cross Protection ◽  
Lymphoid Cells ◽  
Dependent Manner ◽  
Wide Range ◽  
The Cross

Interleukin (IL)-33 is a multifunctional cytokine that mediates type 2 dominated immune responses. In contrast, the role of IL-33 during viral vaccination, which often aims to induce type 1 immunity, has not been fully investigated. Here we examined the effects of IL-33 on influenza vaccine responses. We found that intranasal co-administration of IL-33 with an inactivated influenza virus vaccine increases the vaccine efficacy against influenza infection, not only with the homologous strain, but also heterologous strains including the 2009 H1N1 influenza pandemic strain. The cross-protection was dependent on group 2 innate lymphoid cells (ILC2s), as the beneficial effect of IL-33 on vaccine efficacy was abrogated in ILC2-deficient C57BL/6 Il7r P Cre/+ P Rora P fl/fl P mice. Further, mechanistic studies revealed that IL-33 activated ILC2s potentiate vaccine efficacy by enhancing mucosal humoral immunity, particularly IgA responses, potentially via a Th2 cytokine dependent manner. Our results demonstrate that IL-33-mediated activation of ILC2s is a critical early event that is important for the induction of mucosal humoral immunity, which in turn is responsible for cross-strain protection against influenza. Thus, we reveal a previously unrecognized role for the IL-33/ILC2 axis in establishing broadly protective and long-lasting humoral mucosal immunity against influenza – knowledge that may help develop a universal influenza vaccine. Importance Current influenza vaccines, although capable of protecting against predicted viruses/strains included in the vaccine, are inept at providing cross-protection against emerging/novel strains. Thus, we are in critical need for a universal vaccine that can protect against a wide range of influenza viruses. Our novel findings show that a mucosal vaccination strategy involving the activation of lung ILC2s is highly effective in eliciting cross-protective humoral immunity in the lungs. This suggests that the biology of lung ILC2s can be exploited to increase the cross-reactivity of commercially available influenza subunit vaccines.

scholarly journals DEVELOPMENT OF AN IMPROVED EPSTEIN-BARR VIRUS (EBV) NEUTRALIZING ANTIBODY ASSAY TO FACILITATE DEVELOPMENT OF A PROPHYLACTIC GP350-SUBUNIT EBV VACCINE

2020 ◽  
Vol 12 (1) ◽  
pp. e2020016
Author(s):  
Hui Liu ◽  
Lorraine Gemmell ◽  
Rui Lin ◽  
Fengrong Zuo ◽  
Henry H. Balfour ◽  
...  
Keyword(s):  
High Throughput ◽  
Neutralizing Antibody ◽  
Neutralization Assay ◽  
Epidemiologic Studies ◽  
Antibody Detection ◽  
Healthy Human ◽  
Barr Virus ◽  
Human Sera ◽  
Epstein Barr ◽  
Bioanalytical Assays

No licensed vaccine is available for prevention of EBV-associated diseases, and robust, sensitive, and high-throughput bioanalytical assays are needed to evaluate immunogenicity of gp350 subunit-based candidate EBV vaccines. Here we have developed and improved analytical tools for such a vaccine’s pre-clinical and clinical validation including a gp350-specific antibody detection assay and an EBV-GFP based neutralization assay for measuring EBV specific antibodies in human donors. The sensitivity of our previously published high-throughput EBV-GFP fluorescent focus (FFA)-based neutralization assay was further improved when guinea pig complement was supplemented using a panel of healthy human sera. Anti-gp350 antibody titers, which were evaluated using an anti-gp350 IgG ELISA assay optimized for capture and detection conditions, were moderately correlated to the FFA-based neutralization titers. Overall, these sensitive, and high-throughput bioanalytical assays are capable of characterizing the serologic response to natural EBV infection, with applications in evaluating EBV antibody status in epidemiologic studies and immunogenicity of candidate gp350-subunit EBV vaccines in clinical studies.

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