scholarly journals A Highly Sensitive and Specific SARS-CoV-2 Spike- and Nucleoprotein-Based Fluorescent Multiplex Immunoassay (FMIA) to Measure IgG, IgA, and IgM Class Antibodies

2021 ◽  
Author(s):  
Anna Solastie ◽  
Camilla Virta ◽  
Anu Haveri ◽  
Nina Ekström ◽  
Anu Kantele ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Clinical Performance ◽  
Neutralizing Antibody ◽  
Serological Assay ◽  
Multiplex Immunoassay ◽  
Reliable Estimation ◽  
Highly Sensitive ◽  
Antibody Titers

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) serological assays with excellent clinical performance are essential for reliable estimation of the persistence of immunity after infection or vaccination. In this paper we present a thoroughly validated SARS-CoV-2 serological assay with excellent clinical performance and good comparability to neutralizing antibody titers.

scholarly journals Severe Acute Respiratory Syndrome Coronavirus 2 Neutralizing Antibody Titers in Convalescent Plasma and Recipients in New Mexico: An Open Treatment Study in Patients With Coronavirus Disease 2019

2020 ◽  
Vol 222 (10) ◽  
pp. 1620-1628 ◽  
Author(s):  
Steven B Bradfute ◽  
Ivy Hurwitz ◽  
Alexandra V Yingling ◽  
Chunyan Ye ◽  
Qiuying Cheng ◽  
...  
Keyword(s):  
New Mexico ◽  
Severe Acute Respiratory Syndrome ◽  
Neutralizing Antibody ◽  
Traditional Food ◽  
Neutralizing Activity ◽  
Time Points ◽  
Before And After ◽  
Open Treatment ◽  
Antibody Titers ◽  
Donor Plasma

Abstract Background Convalescent plasma (CP) is a potentially important therapy for coronavirus disease 2019 (COVID-19). However, knowledge regarding neutralizing antibody (NAb) titers in donor plasma and their impact in patients with acute COVID-19 remains largely undetermined. We measured NAb titers in CP and in patients with acute COVID-19 before and after transfusion through the traditional Food and Drug Administration investigational new drug pathway. Methods We performed a single-arm interventional trial measuring NAb and total antibody titers before and after CP transfusion over a 14-day period in hospitalized patients with laboratory-confirmed severe acute respiratory syndrome coronavirus 2 infection. Results NAb titers in the donor CP units were low (<1:40 to 1:160) and had no effect on recipient neutralizing activity 1 day after transfusion. NAb titers were detected in 6 of 12 patients on enrollment and in 11 of 12 at ≥2 time points. Average titers peaked on day 7 and declined toward day 14 (P = .004). Nab titers and immunoglobulin G levels were correlated in donor plasma units (ρ = 0.938; P < .001) and in the cumulative patient measures (ρ = 0.781; P < .001). Conclusions CP infusion did not alter recipient NAb titers. Prescreening of CP may be necessary for selecting donors with high titers of neutralizing activity for infusion into patients with COVID-19. Clinical Trials Registration NCT04434131.

scholarly journals Severe Acute Respiratory Syndrome-Associated Coronavirus Vaccines Formulated with Delta Inulin Adjuvants Provide Enhanced Protection while Ameliorating Lung Eosinophilic Immunopathology

2014 ◽  
Vol 89 (6) ◽  
pp. 2995-3007 ◽  
Author(s):  
Yoshikazu Honda-Okubo ◽  
Dale Barnard ◽  
Chun Hao Ong ◽  
Bi-Hung Peng ◽  
Chien-Te Kent Tseng ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Neutralizing Antibodies ◽  
Case Fatality ◽  
Neutralizing Antibody ◽  
The Elderly ◽  
Spike Protein ◽  
Interleukin 4 ◽  
Unique Problem ◽  
Antibody Titers ◽  
Ifn Γ

ABSTRACTAlthough the severe acute respiratory syndrome-associated coronavirus (SARS-CoV) epidemic was controlled by nonvaccine measures, coronaviruses remain a major threat to human health. The design of optimal coronavirus vaccines therefore remains a priority. Such vaccines present major challenges: coronavirus immunity often wanes rapidly, individuals needing to be protected include the elderly, and vaccines may exacerbate rather than prevent coronavirus lung immunopathology. To address these issues, we compared in a murine model a range of recombinant spike protein or inactivated whole-virus vaccine candidates alone or adjuvanted with either alum, CpG, or Advax, a new delta inulin-based polysaccharide adjuvant. While all vaccines protected against lethal infection, addition of adjuvant significantly increased serum neutralizing-antibody titers and reduced lung virus titers on day 3 postchallenge. Whereas unadjuvanted or alum-formulated vaccines were associated with significantly increased lung eosinophilic immunopathology on day 6 postchallenge, this was not seen in mice immunized with vaccines formulated with delta inulin adjuvant. Protection against eosinophilic immunopathology by vaccines containing delta inulin adjuvants correlated better with enhanced T-cell gamma interferon (IFN-γ) recall responses rather than reduced interleukin-4 (IL-4) responses, suggesting that immunopathology predominantly reflects an inadequate vaccine-induced Th1 response. This study highlights the critical importance for development of effective and safe coronavirus vaccines of selection of adjuvants based on the ability to induce durable IFN-γ responses.IMPORTANCECoronaviruses such as SARS-CoV and Middle East respiratory syndrome-associated coronavirus (MERS-CoV) cause high case fatality rates and remain major human public health threats, creating a need for effective vaccines. While coronavirus antigens that induce protective neutralizing antibodies have been identified, coronavirus vaccines present a unique problem in that immunized individuals when infected by virus can develop lung eosinophilic pathology, a problem that is further exacerbated by the formulation of SARS-CoV vaccines with alum adjuvants. This study shows that formulation of SARS-CoV spike protein or inactivated whole-virus vaccines with novel delta inulin-based polysaccharide adjuvants enhances neutralizing-antibody titers and protection against clinical disease but at the same time also protects against development of lung eosinophilic immunopathology. It also shows that immunity achieved with delta inulin adjuvants is long-lived, thereby overcoming the natural tendency for rapidly waning coronavirus immunity. Thus, delta inulin adjuvants may offer a unique ability to develop safer and more effective coronavirus vaccines.

scholarly journals Accurate SARS-CoV-2 seroprevalence surveys require robust multi-antigen assays

2020 ◽  
Author(s):  
Christos Fotis ◽  
Nikolaos Meimetis ◽  
Nikos Tsolakos ◽  
Marianna Politou ◽  
Karolina Akinosoglou ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Blood Donors ◽  
Clinical Performance ◽  
Antibody Responses ◽  
Receptor Binding Domain ◽  
Accurate Identification ◽  
Serological Tests ◽  
Partial Agreement ◽  
Multiplex Immunoassay ◽  
Single Antigen

AbstractThere is a plethora of severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) serological tests based either on nucleocapsid phosphoprotein (N), S1-subunit of spike glycoprotein (S1) or receptor binding domain (RBD). Although these single-antigen based tests demonstrate high clinical performance, there is growing evidence regarding their limitations in epidemiological serosurveys. To address this, we developed a Luminex-based multiplex immunoassay that detects total antibodies (IgG/IgM/IgA) against the N, S1 and RBD antigens and used it to compare antibody responses in 1,225 blood donors across Greece. Seroprevalence based on single-antigen readouts was strongly influenced by both the antigen type and cut-off value and ranged widely [0.8% (95% CI, 0.4-1.5%)-7.5% (95% CI, 6.0-8.9%)]. A multi-antigen approach requiring partial agreement between RBD and N or S1 readouts (RBD&N|S1 rule) was less affected by cut-off selection, resulting in robust seroprevalence estimation [0.6% (95% CI, 0.3-1.1%)-1.2% (95% CI, 0.7-2.0%)] and accurate identification of seroconverted individuals.

scholarly journals A Live Attenuated Severe Acute Respiratory Syndrome Coronavirus Is Immunogenic and Efficacious in Golden Syrian Hamsters

2008 ◽  
Vol 82 (15) ◽  
pp. 7721-7724 ◽  
Author(s):  
Elaine W. Lamirande ◽  
Marta L. DeDiego ◽  
Anjeanette Roberts ◽  
Jadon P. Jackson ◽  
Enrique Alvarez ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Respiratory Tract ◽  
Protective Efficacy ◽  
Neutralizing Antibody ◽  
High Serum ◽  
Wild Type Virus ◽  
Live Attenuated Vaccine ◽  
Virus Challenge ◽  
Antibody Titers ◽  
Efficacious Vaccine

ABSTRACT The immunogenicity and protective efficacy of a live attenuated vaccine consisting of a recombinant severe acute respiratory syndrome (SARS) coronavirus lacking the E gene (rSARS-CoV-ΔE) were studied using hamsters. Hamsters immunized with rSARS-CoV-ΔE developed high serum-neutralizing antibody titers and were protected from replication of homologous (SARS-CoV Urbani) and heterologous (GD03) SARS-CoV in the upper and lower respiratory tract. rSARS-CoV-ΔE-immunized hamsters remained active following wild-type virus challenge, while mock-immunized hamsters displayed decreased activity. Despite being attenuated in replication in the respiratory tract, rSARS-CoV-ΔE is an immunogenic and efficacious vaccine in hamsters.

scholarly journals Dynamics of Neutralizing Antibody Titers in the Months After Severe Acute Respiratory Syndrome Coronavirus 2 Infection

2020 ◽  
Author(s):  
Katharine H D Crawford ◽  
Adam S Dingens ◽  
Rachel Eguia ◽  
Caitlin R Wolf ◽  
Naomi Wilcox ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Symptom Onset ◽  
Neutralizing Antibodies ◽  
Severe Disease ◽  
Neutralizing Antibody ◽  
Spike Protein ◽  
Antibody Titers ◽  
Antibody Levels ◽  
Time Frames ◽  
Initial Peak

Abstract Most individuals infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) develop neutralizing antibodies that target the viral spike protein. In this study, we quantified how levels of these antibodies change in the months after SARS-CoV-2 infection by examining longitudinal samples collected approximately 30–152 days after symptom onset from a prospective cohort of 32 recovered individuals with asymptomatic, mild, or moderate-severe disease. Neutralizing antibody titers declined an average of about 4-fold from 1 to 4 months after symptom onset. This decline in neutralizing antibody titers was accompanied by a decline in total antibodies capable of binding the viral spike protein or its receptor-binding domain. Importantly, our data are consistent with the expected early immune response to viral infection, where an initial peak in antibody levels is followed by a decline to a lower plateau. Additional studies of long-lived B cells and antibody titers over longer time frames are necessary to determine the durability of immunity to SARS-CoV-2.

scholarly journals Accurate SARS-CoV-2 seroprevalence surveys require robust multi-antigen assays

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Christos Fotis ◽  
Nikolaos Meimetis ◽  
Nikos Tsolakos ◽  
Marianna Politou ◽  
Karolina Akinosoglou ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Blood Donors ◽  
Clinical Performance ◽  
Antibody Responses ◽  
Receptor Binding Domain ◽  
Accurate Identification ◽  
Serological Tests ◽  
Partial Agreement ◽  
Multiplex Immunoassay ◽  
Single Antigen

AbstractThere is a plethora of severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) serological tests based either on nucleocapsid phosphoprotein (N), S1-subunit of spike glycoprotein (S1) or receptor binding domain (RBD). Although these single-antigen based tests demonstrate high clinical performance, there is growing evidence regarding their limitations in epidemiological serosurveys. To address this, we developed a Luminex-based multiplex immunoassay that detects total antibodies (IgG/IgM/IgA) against the N, S1 and RBD antigens and used it to compare antibody responses in 1225 blood donors across Greece. Seroprevalence based on single-antigen readouts was strongly influenced by both the antigen type and cut-off value and ranged widely [0.8% (95% CI 0.4–1.5%)–7.5% (95% CI 6.0–8.9%)]. A multi-antigen approach requiring partial agreement between RBD and N or S1 readouts (RBD&N|S1 rule) was less affected by cut-off selection, resulting in robust seroprevalence estimation [0.6% (95% CI 0.3–1.1%)–1.2% (95% CI 0.7–2.0%)] and accurate identification of seroconverted individuals.

scholarly journals Longitudinal Serological Analysis and Neutralizing Antibody Levels in Coronavirus Disease 2019 Convalescent Patients

2020 ◽  
Author(s):  
Frauke Muecksch ◽  
Helen Wise ◽  
Becky Batchelor ◽  
Maria Squires ◽  
Elizabeth Semple ◽  
...  
Keyword(s):  
Neutralizing Antibody ◽  
Neutralization Titer ◽  
Serological Assay ◽  
Antibody Assays ◽  
Antibody Titers ◽  
Binding Antibody ◽  
Antibody Levels ◽  
Prior Infection ◽  
Commercial Platform

Abstract Background Understanding the longitudinal trajectory of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies is crucial for diagnosis of prior infection and predicting future immunity. Methods We conducted a longitudinal analysis of coronavirus disease 2019 convalescent patients, with neutralizing antibody assays and SARS-CoV-2 serological assay platforms using SARS-CoV-2 spike (S) or nucleocapsid (N) antigens. Results Sensitivities of serological assays in diagnosing prior SARS-CoV-2 infection changed with time. One widely used commercial platform that had an initial sensitivity of >95% declined to 71% at 81–100 days after diagnosis. The trajectories of median binding antibody titers measured over approximately 3–4 months were not dependent on the use of SARS-CoV-2 N or S proteins as antigen. The median neutralization titer decreased by approximately 45% per month. Each serological assay gave quantitative antibody titers that were correlated with SARS-CoV-2 neutralization titers, but S-based serological assay measurements better predicted neutralization potency. Correlation between S-binding and neutralization titers deteriorated with time, and decreases in neutralization titers were not predicted by changes in S-binding antibody titers. Conclusions Different SARS-CoV-2 serological assays are more or less well suited for surveillance versus prediction of serum neutralization potency. Extended follow-up should facilitate the establishment of appropriate serological correlates of protection against SARS-CoV-2 reinfection.

scholarly journals Serological Responses in Patients with Severe Acute Respiratory Syndrome Coronavirus Infection and Cross-Reactivity with Human Coronaviruses 229E, OC43, and NL63

2005 ◽  
Vol 12 (11) ◽  
pp. 1317-1321 ◽  
Author(s):  
K. H. Chan ◽  
V. C. C. Cheng ◽  
P. C. Y. Woo ◽  
S. K. P. Lau ◽  
L. L. M. Poon ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Geometric Mean ◽  
Neutralizing Antibody ◽  
Cross Reactivity ◽  
Serological Response ◽  
Igg Antibody ◽  
Unrelated Control ◽  
Barr Virus ◽  
Antibody Titers ◽  
Human Coronaviruses

ABSTRACT The serological response profile of severe acute respiratory syndrome (SARS) coronavirus (CoV) infection was defined by neutralization tests and subclass-specific immunofluorescent (IF) tests using serial sera from 20 patients. SARS CoV total immunoglobulin (Ig) (IgG, IgA, and IgM [IgGAM]) was the first antibody to be detectable. There was no difference in time to seroconversion between the patients who survived (n = 14) and those who died (n = 6). Although SARS CoV IgM was still detectable by IF tests with 8 of 11 patients at 7 months postinfection, the geometric mean titers dropped from 282 at 1 month postinfection to 19 at 7 months (P = 0.001). In contrast, neutralizing antibody and SARS CoV IgGAM and IgG antibody titers remained stable over this period. The SARS CoV antibody response was sometimes associated with an increase in preexisting IF IgG antibody titers for human coronaviruses OC43, 229E, and NL63. There was no change in IF IgG titer for virus capsid antigen from the herpesvirus that was used as an unrelated control, Epstein-Barr virus. In contrast, patients who had OC43 infections, and probably also 229E infections, without prior exposure to SARS CoV had increases of antibodies specific for the infecting virus but not for SARS CoV. There is a need for awareness of cross-reactive antibody responses between coronaviruses when interpreting IF serology.

Presence of antibody in virus-infected brain cells of SSPE ferrets

1983 ◽  
Vol 41 ◽  
pp. 804-805
Author(s):  
Hannah R. Brown ◽  
Tammy L. Donato ◽  
Halldor Thormar
Keyword(s):  
Measles Virus ◽  
Plasma Cells ◽  
Subacute Sclerosing Panencephalitis ◽  
Protein A ◽  
Neutralizing Antibody ◽  
Brain Cells ◽  
Antibody Titers ◽  
A Cell ◽  
The Central Nervous System ◽  
The Brain

Measles virus specific immunoglobulin G (IgG) has been found in the brains of patients with subacute sclerosing panencephalitis (SSPE), a slowly progressing disease of the central nervous system (CNS) in children. IgG/albumin ratios indicate that the antibodies are synthesized within the CNS. Using the ferret as an animal model to study the disease, we have been attempting to localize the Ig's in the brains of animals inoculated with a cell associated strain of SSPE. In an earlier report, preliminary results using Protein A conjugated to horseradish peroxidase (PrAPx) (Dynatech Diagnostics Inc., South Windham, ME.) to detect antibodies revealed the presence of immunoglobulin mainly in antibody-producing plasma cells in inflammatory lesions and not in infected brain cells.In the present experiment we studied the brain of an SSPE ferret with neutralizing antibody titers of 1:1024 in serum and 1:512 in CSF at time of sacrifice 7 months after i.c. inoculation with SSPE measles virus-infected cells. The animal was perfused with saline and portions of the brain and spinal cord were immersed in periodate-lysine-paraformaldehyde (P-L-P) fixative. The ferret was not perfused with fixative because parts of the brain were used for virus isolation.

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