scholarly journals Donor Anti-Spike Immunity is Related to Recipient Recovery and Can Predict the Efficacy of Convalescent Plasma Units.

2021 ◽  
Author(s):  
Sanath Kumar Janaka ◽  
William Hartman ◽  
HuiHui Mou ◽  
Michael Frazan ◽  
Susan L Stramer ◽  
...  
Keyword(s):  
Passive Immunization ◽  
Therapeutic Benefit ◽  
Spike Protein ◽  
Plasma Samples ◽  
Viral Neutralization ◽  
Neutralizing Activity ◽  
Novel Coronavirus ◽  
Option Selection ◽  
Antibody Levels ◽  
Design And Methods

Background: The novel coronavirus, SARS-CoV2 that causes COVID-19 has resulted in the death of more than 2.31 million people within the last year and yet no cure exists. Whereas passive immunization with COVID-19 convalescent plasma (CCP) provides a safe and viable option, selection of optimal units for therapy and lack of clear therapeutic benefit from transfusion remain as barriers to the use of CCP. Study design and methods: To identify plasma that is expected to benefit recipients, we measured anti-SARS-CoV2 antibody levels using clinically available serological assays and correlated with the neutralizing activity of CCP from donors. Neutralizing titer of plasma samples was measured by assaying infectivity of SARS-CoV-2 spike protein pseudotyped retrovirus particles in the presence of dilutions of plasma samples. We also used this assay to identify evidence of passive transfusion of neutralizing activity in CCP recipients. Results: Viral neutralization and anti-spike protein antibodies in 109 samples from 87 plasma donors were highly varied but modestly correlated with each other. Recipients who died of COVID-19 were found to have been transfused with units with lower anti-spike antibody levels and neutralizing activity. Passive transfer of neutralization activity was documented in 62% of antibody naive plasma recipients. Conclusions: Since viral neutralization is the goal of CCP transfusion, our observations not only support the use of anti-spike SARS-CoV2 serology tests to identify beneficial CCP units, but also support the therapeutic value of convalescent plasma with high titers of anti-spike antibodies.

scholarly journals Two Opposing Roles of SARS-CoV-2 RBD-Reactive Antibodies in Pre-Pandemic Plasma Samples From Elderly People in ACE2-Mediated Pseudovirus Infection

2022 ◽  
Vol 12 ◽  
Author(s):  
Kyu-Young Sim ◽  
Gwang-Hoon Ko ◽  
So-Eun Bae ◽  
Kyu Yeong Choi ◽  
Jung Sup Lee ◽  
...  
Keyword(s):  
Elderly People ◽  
Underlying Mechanism ◽  
Plasma Samples ◽  
Igg Antibody ◽  
Neutralizing Activity ◽  
Korean People ◽  
Reactive Plasma ◽  
Novel Coronavirus ◽  
Antibody Levels ◽  
Reactive Antibody

A novel coronavirus designated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged and caused an outbreak of unusual viral pneumonia. Several reports have shown that cross-reactive antibodies against SARS-CoV-2 also exist in people unexposed to this virus. However, the neutralizing activity of cross-reactive antibodies is controversial. Here, we subjected plasma samples from SARS-CoV-2-unexposed elderly Korean people (n = 119) to bead-based IgG antibody analysis. SARS-CoV-2 S1 subunit-reactive IgG antibody analysis detected positive signals in some samples (59 of 119, 49.6%). SARS-CoV-2 receptor-binding domain (RBD)-reactive antibody levels were most significantly correlated with human coronavirus-HKU1 S1 subunit-reactive antibody levels. To check the neutralizing activity of plasma samples, the SARS-CoV-2 spike pseudotype neutralizing assay was used. However, the levels of cross-reactive antibodies did not correlate with neutralizing activity. Instead, SARS-CoV-2 pseudovirus infection was neutralized by some RBD-reactive plasma samples (n = 9, neutralization ≥ 25%, P ≤ 0.05), but enhanced by other RBD-reactive plasma samples (n = 4, neutralization ≤ -25%, P ≤ 0.05). Interestingly, the blood plasma groups with enhancing and neutralizing effects had high levels of SARS-CoV-2 RBD-reactive antibodies than the plasma group that had no effect. These results suggest that some SARS-CoV-2 RBD-reactive antibodies from pre-pandemic elderly people exert two opposing functions during SARS-CoV-2 pseudovirus infection. In conclusion, preformed RBD-reactive antibodies may have two opposing functions, namely, protecting against and enhancing viral infection. Analysis of the epitopes of preformed antibodies will be useful to elucidate the underlying mechanism.

scholarly journals Evaluation of the IgG antibody response to SARS CoV-2 infection and performance of a lateral flow immunoassay: cross-sectional and longitudinal analysis over 11 months

BMJ Open ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. e048142
Author(s):  
Louise J Robertson ◽  
Julie S Moore ◽  
Kevin Blighe ◽  
Kok Yew Ng ◽  
Nigel Quinn ◽  
...  
Keyword(s):  
Northern Ireland ◽  
Post Infection ◽  
Rapid Test ◽  
Spike Protein ◽  
Lateral Flow Immunoassay ◽  
Plasma Samples ◽  
Igg Antibodies ◽  
Igg Antibody ◽  
The Uk ◽  
Antibody Levels

ObjectiveTo evaluate the dynamics and longevity of the humoral immune response to SARS-CoV-2 infection and assess the performance of professional use of the UK-RTC AbC-19 Rapid Test lateral flow immunoassay (LFIA) for the target condition of SARS-CoV-2 spike protein IgG antibodies.DesignNationwide serological study.SettingNorthern Ireland, UK, May 2020–February 2021.ParticipantsPlasma samples were collected from a diverse cohort of individuals from the general public (n=279), Northern Ireland healthcare workers (n=195), pre-pandemic blood donations and research studies (n=223) and through a convalescent plasma programme (n=183). Plasma donors (n=101) were followed with sequential samples over 11 months post-symptom onset.Main outcome measuresSARS-CoV-2 antibody levels in plasma samples using Roche Elecsys Anti-SARS-CoV-2 IgG/IgA/IgM, Abbott SARS-CoV-2 IgG and EuroImmun IgG SARS-CoV-2 ELISA immunoassays over time. UK-RTC AbC-19 LFIA sensitivity and specificity, estimated using a three-reference standard system to establish a characterised panel of 330 positive and 488 negative SARS-CoV-2 IgG samples.ResultsWe detected persistence of SARS-CoV-2 IgG antibodies for up to 10 months post-infection, across a minimum of two laboratory immunoassays. On the known positive cohort, the UK-RTC AbC-19 LFIA showed a sensitivity of 97.58% (95.28% to 98.95%) and on known negatives, showed specificity of 99.59% (98.53 % to 99.95%).ConclusionsThrough comprehensive analysis of a cohort of pre-pandemic and pandemic individuals, we show detectable levels of IgG antibodies, lasting over 46 weeks when assessed by EuroImmun ELISA, providing insight to antibody levels at later time points post-infection. We show good laboratory validation performance metrics for the AbC-19 rapid test for SARS-CoV-2 spike protein IgG antibody detection in a laboratory-based setting.

scholarly journals Predicting the Efficacy of COVID-19 Convalescent Plasma Donor Units with the Lumit Dx anti-Receptor Binding Domain Assay

2021 ◽  
Author(s):  
Sanath Kumar Janaka ◽  
Natasha M Clark ◽  
David T Evans ◽  
Joseph P Connor
Keyword(s):  
Receptor Binding ◽  
Therapeutic Option ◽  
Passive Immunization ◽  
Binding Domain ◽  
Receptor Binding Domain ◽  
S Protein ◽  
Antibody Assays ◽  
Antibody Titers ◽  
Novel Coronavirus ◽  
Design And Methods

AbstractBackgroundThe novel coronavirus SARS-CoV2 that causes COVID-19 has resulted in the death of more than 2.5 million people, but no cure exists. Although passive immunization with COVID-19 convalescent plasma (CCP) provides a safe and viable therapeutic option, the selection of optimal units for therapy in a timely fashion remains a barrier.Study design and methodsSince virus neutralization is a necessary characteristic of plasma that can benefit recipients, the neutralizing titers of plasma samples were measured using a retroviral-pseudotype assay. Binding antibody titers to the spike (S) protein were also determined by a clinically available serological assay (Ortho-Vitros total IG), and an in-house ELISA. The results of these assays were compared to a measurement of antibodies directed to the receptor binding domain (RBD) of the SARS-CoV2 S protein (Promega Lumit Dx).ResultsAll measures of antibodies were highly variable, but correlated, to different degrees, with each other. However, the anti-RBD antibodies correlated with viral neutralizing titers to a greater extent than the other antibody assays.DiscussionOur observations support the use of an anti-RBD assay such as the Lumit Dx assay, as an optimal predictor of the neutralization capability of CCP.

scholarly journals Spike protein antibodies mediate the apparent correlation between SARS-CoV-2 nucleocapsid antibodies and neutralization test results

2021 ◽  
Author(s):  
Thomas Perkmann ◽  
Thomas Koller ◽  
Nicole Perkmann-Nagele ◽  
Miriam Klausberger ◽  
Mark Duerkop ◽  
...  
Keyword(s):  
Partial Correlation ◽  
Correlation Coefficients ◽  
Spike Protein ◽  
Viral Neutralization ◽  
Mediation Analyses ◽  
Apparent Correlation ◽  
Antibody Assays ◽  
Protein Components ◽  
Antibody Levels ◽  
Viral Nucleocapsid

AbstractObjectivesSARS-CoV-2 infection induces the formation of different antibodies. However, not all of which might prevent the virus from entering the cell, although their concentrations correlate with the titers of viral neutralization tests (NTs). Antibodies against the viral nucleocapsid (NC), e.g., can be classified as such. We aimed to prove the hypothesis that the apparent correlation between NC-antibody levels and NT-titers is mediated by simultaneously occurring antibodies against viral spike-protein components.MethodsWe included 64 individuals with previous SARS-CoV-2 infection (>14d after symptom onset). SARS-CoV-2 antibodies against the NC (Roche total antibody ECLIA, Abbott IgG CMIA) and spike-protein (Technozym RBD ELISA, DiaSorin S1/S2 CLIA) were measured, and neutralization tests were performed. The effect of spike-protein antibodies on the correlation between NC-antibodies and NT-titers was evaluated by partial correlation and mediation analyses.ResultsBoth tested assays assessing antibodies against the NC correlated significantly with NT titers: Abbott ρ=0.742, P<0.0001; Roche ρ=0.365, P<0.01. However, when controlling the rank correlations for the presence of RBD or S1/S2 antibodies, correlation coefficients dropped to ρ=0.318/ρ=0.329 (P<0.05/P<0.01), respectively for Abbott and vanished for Roche. As a result, only a maximum of 11% of NT titer variability could be explained by NC-antibody levels.ConclusionsOur data suggest that the apparent correlation between NC antibodies and NT titers is strongly mediated by co-occurring RBD antibody concentrations. To avoid falsely implied causal relationships, all correlation analyses of non-spike-associated antibody assays and neutralization assays should include a partial correlation analysis to exclude a possible mediator effect of spike-associated antibodies.

scholarly journals Longitudinal variation in SARS-CoV-2 antibody levels and emergence of viral variants: implications for the ability of serological assays to predict immunity.

2021 ◽  
Author(s):  
Frauke Muecksch ◽  
Helen Wise ◽  
Kate Templeton ◽  
Becky Batchelor ◽  
Maria Squires ◽  
...  
Keyword(s):  
High Throughput ◽  
Neutralizing Antibody ◽  
Spike Protein ◽  
Serological Tests ◽  
Neutralization Activity ◽  
Neutralizing Activity ◽  
Quantitative Measurements ◽  
Antibody Titers ◽  
Antibody Levels ◽  
Selection Of

Background Serological assays are being deployed to monitor antibody responses in SARS-CoV-2 convalescents and vaccine recipients. There is a need to determine whether such assays can predict immunity, as antibody levels wane and viral variants emerge. Methods We measured antibodies in a cohort of SARS-CoV-2 infected patients using several high-throughput serological tests and functional neutralization assays. The effects of time and spike protein sequence variation on the performance and predictive value of the various assays was assessed. Findings Neutralizing antibody titers decreased over the first few months post-infection but stabilized thereafter, at about 30% of the level observed shortly after infection. Serological assays commonly used to measure antibodies against SARS-CoV-2 displayed a range of sensitivities that declined to varying extents over time. Quantitative measurements generated by serological assays based on the spike protein were better at predicting neutralizing antibody titers than assays based on nucleocapsid, but performance was variable and manufacturer positivity thresholds were not able to predict the presence or absence of detectable neutralizing activity. Even though there was some deterioration in correlation between serological measurements and functional neutralization activity, some assays maintained an ability to predict neutralizing titers, even against variants of concern. Interpretation The ability of high throughput serological assays to predict neutralizing antibody titers is likely crucial for evaluation of immunity at the population scale. These data will facilitate the selection of the most suitable assays as surrogates of functional neutralizing activity and suggest that such measurements may have utility in clinical practice.

scholarly journals Function Is More Reliable than Quantity to Follow Up the Humoral Response to the Receptor-Binding Domain of SARS-CoV-2-Spike Protein after Natural Infection or COVID-19 Vaccination

Viruses ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1972
Author(s):  
Carlos A. Sariol ◽  
Petraleigh Pantoja ◽  
Crisanta Serrano-Collazo ◽  
Tiffany Rosa-Arocho ◽  
Albersy Armina-Rodríguez ◽  
...  
Keyword(s):  
Immune Response ◽  
Natural Infection ◽  
Vaccine Dose ◽  
Humoral Response ◽  
Neutralizing Antibody ◽  
Viral Neutralization ◽  
Neutralizing Activity ◽  
Humoral Immune ◽  
Antibody Assays ◽  
Novel Coronavirus

Both the SARS-CoV-2 pandemic and emergence of variants of concern have highlighted the need for functional antibody assays to monitor the humoral response over time. Antibodies directed against the spike (S) protein of SARS-CoV-2 are an important component of the neutralizing antibody response. In this work, we report that in a subset of patients—despite a decline in total S-specific antibodies—neutralizing antibody titers remain at a similar level for an average of 98 days in longitudinal sampling of a cohort of 59 Hispanic/Latino patients exposed to SARS-CoV-2. Our data suggest that 100% of seroconverting patients make detectable neutralizing antibody responses which can be quantified by a surrogate viral neutralization test. Examination of sera from ten out of the 59 subjects which received mRNA-based vaccination revealed that both IgG titers and neutralizing activity of sera were higher after vaccination compared to a cohort of 21 SARS-CoV-2 naïve subjects. One dose was sufficient for the induction of a neutralizing antibody, but two doses were necessary to reach 100% surrogate virus neutralization in subjects irrespective of previous SARS-CoV-2 natural infection status. Like the pattern observed after natural infection, the total anti-S antibodies titers declined after the second vaccine dose; however, neutralizing activity remained relatively constant for more than 80 days after the first vaccine dose. Furthermore, our data indicates that—compared with mRNA vaccination—natural infection induces a more robust humoral immune response in unexposed subjects. This work is an important contribution to understanding the natural immune response to the novel coronavirus in a population severely impacted by SARS-CoV-2. Furthermore, by comparing the dynamics of the immune response after the natural infection vs. the vaccination, these findings suggest that functional neutralizing antibody tests are more relevant indicators than the presence or absence of binding antibodies.

scholarly journals Induction of Th1/Th2-Balanced Protection Against SARS-CoV-2 Through Mucosal Delivery of An Adenovirus Vaccine Expressing an Engineered Spike Protein

2021 ◽  
Author(s):  
Nai-Hsiang Chung ◽  
Ying-Chin Chen ◽  
Shiu-Ju Yang ◽  
Yu-Ching Lin ◽  
Horng-Yunn Dou ◽  
...  
Keyword(s):  
Cellular Response ◽  
Body Weight Loss ◽  
Humoral Response ◽  
Protein S ◽  
Spike Protein ◽  
Th2 Cells ◽  
Neutralizing Activity ◽  
Viral Loads ◽  
Mucosal Delivery ◽  
Antibody Levels

Abstract We developed a series of recombinant human type 5 adenoviruses that express the full-length or membrane-truncated spike protein (S) of SARS-CoV-2 (AdCoV2-S or AdCoV2-SdTM, respectively). We tested the immunoprotective efficacy against SARS-CoV-2 via intranasal (i.n.) or subcutaneous (s.c.) immunization in a rodent model following two-dose immunizations. Mucosal delivery of adenovirus (Ad) vaccines could induce anti-SARS-CoV-2 IgG and IgA in the serum and in the mucosal, respectively as indicated by vaginal wash (vw). Serum anti-SARS-CoV-2 IgG but not IgA was induced in the vw by s.c. injection of AdCoV2-S. Intranasal administration of AdCoV2-S was able to induce higher anti-SARS-CoV-2 antibody levels than s.c. injection. Immunization with AdCoV2-SdTM induced a lower antibody response than AdCoV2-S. In addition, the degree of neutralization of clinically isolated SARS-CoV-2 in the serum correlated with the above anti-SARS-CoV-2 responses; the most potent neutralizing activity was observed in the AdCoV2-S i.n. group, and less viral neutralizing activity was observed in response to AdCoV2-S s.c. and AdCoV2dTM i.n. Novelty, S-specific IgG1 which represented Th2-mediated humoral response was dominantly induced in Ad i.n.-immunized serum in contrast to more IgG2a which represented Th1-mediated cellular response found in Ad s.c.-immunized serum. The activation of S-specific IFN-ɣ and IL-4 in Th1 and Th2 cells, respectively, was observed in the AdCoV2s i.n. and s.c. groups, indicating the Th1/Th2-balenced immunity was activated. During the protection study, two doses of i.n. AdCoV2-S or i.n. AdCoV2-SdTM significantly prevented body weight loss and reduced pulmonary viral loads in hamsters. A significant reduction in inflammation in the lungs was observed in AdCoV-S-immunized hamsters following a SARS-CoV-2 challenge. It correlated to Th1 cytokine but no inflammatory cytokines secretions found in i.n. AdCoV-immunized respiratory tract. These results indicate that intranasal delivery of AdCoV2-S vaccines is safe and potent at preventing SARS-CoV-2 infections.

scholarly journals Predicting the efficacy of COVID-19 convalescent plasma donor units with the Lumit Dx anti-receptor binding domain assay

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0253551
Author(s):  
Sanath Kumar Janaka ◽  
Natasha M. Clark ◽  
David T. Evans ◽  
Huihui Mou ◽  
Michael Farzan ◽  
...  
Keyword(s):  
Receptor Binding ◽  
Therapeutic Option ◽  
Passive Immunization ◽  
Binding Domain ◽  
Receptor Binding Domain ◽  
S Protein ◽  
Antibody Assays ◽  
Antibody Titers ◽  
Novel Coronavirus ◽  
Design And Methods

Background The novel coronavirus SARS-CoV2 that causes COVID-19 has resulted in the death of more than 2.5 million people, but no cure exists. Although passive immunization with COVID-19 convalescent plasma (CCP) provides a safe and viable therapeutic option, the selection of optimal units for therapy in a timely fashion remains a barrier. Study design and methods Since virus neutralization is a necessary characteristic of plasma that can benefit recipients, the neutralizing titers of plasma samples were measured using a retroviral-pseudotype assay. Binding antibody titers to the spike (S) protein were also determined by a clinically available serological assay (Ortho-Vitros total IG), and an in-house ELISA. The results of these assays were compared to a measurement of antibodies directed to the receptor binding domain (RBD) of the SARS-CoV2 S protein (Promega Lumit Dx). Results All measures of antibodies were highly variable, but correlated, to different degrees, with each other. However, the anti-RBD antibodies correlated with viral neutralizing titers to a greater extent than the other antibody assays. Discussion Our observations support the use of an anti-RBD assay such as the Lumit Dx assay, as an optimal predictor of the neutralization capability of CCP.

scholarly journals Immunization with RBD-P2 and N protects against SARS-CoV-2 in nonhuman primates

2021 ◽  
Vol 7 (22) ◽  
pp. eabg7156
Author(s):  
So-Hee Hong ◽  
Hanseul Oh ◽  
Yong Wook Park ◽  
Hye Won Kwak ◽  
Eun Young Oh ◽  
...  
Keyword(s):  
Nucleocapsid Protein ◽  
Nonhuman Primates ◽  
Vaccine Candidate ◽  
Statistical Significance ◽  
Neutralizing Antibody ◽  
Spike Protein ◽  
Vaccine Candidates ◽  
Cell Responses ◽  
Antibody Levels ◽  
Further Development

Since the emergence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), various vaccines are being developed, with most vaccine candidates focusing on the viral spike protein. Here, we developed a previously unknown subunit vaccine comprising the receptor binding domain (RBD) of the spike protein fused with the tetanus toxoid epitope P2 (RBD-P2) and tested its efficacy in rodents and nonhuman primates (NHPs). We also investigated whether the SARS-CoV-2 nucleocapsid protein (N) could increase vaccine efficacy. Immunization with N and RBD-P2 (RBDP2/N) + alum increased T cell responses in mice and neutralizing antibody levels in rats compared with those obtained using RBD-P2 + alum. Furthermore, in NHPs, RBD-P2/N + alum induced slightly faster SARS-CoV-2 clearance than that induced by RBD-P2 + alum, albeit without statistical significance. Our study supports further development of RBD-P2 as a vaccine candidate against SARS-CoV-2. Also, it provides insights regarding the use of N in protein-based vaccines against SARS-CoV-2.

scholarly journals The Road towards Polyclonal Anti-SARS-CoV-2 Immunoglobulins (Hyperimmune Serum) for Passive Immunization in COVID-19

Life ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 144
Author(s):  
Daniele Focosi ◽  
Marco Tuccori ◽  
Massimo Franchini
Keyword(s):  
Neutralizing Antibodies ◽  
Passive Immunization ◽  
Spike Protein ◽  
Controlled Trials ◽  
Disease Course ◽  
Early Disease ◽  
Hyperimmune Serum ◽  
The Road ◽  
Randomized Controlled ◽  
Pros And Cons

Effective treatments specific for COVID-19 are still lacking. In the setting of passive immunotherapies based on neutralizing antibodies (nAbs), randomized controlled trials of COVID-19 convalescent plasma (CCP) anti-SARS-CoV-2 Spike protein monoclonal antibodies (mAb), which have been granted emergency use authorization, have suggested benefit in early disease course (less than 72 hours from symptoms and seronegative). Meanwhile, polyclonal immunoglobulins (i.e., hyperimmune serum), derived either from CCP donations or from animals immunized with SARS-CoV-2 antigens, are likely to become the next nAb-derived candidate. We here discuss the pros and cons of hyperimmune serum versus CCP and mAb, and summarize the ongoing clinical trials of COVID-19 hyperimmune sera.

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