Anti-SARS-CoV-2 Immunoglobulin Isotypes, and Neutralization Activity Against Viral Variants, According to BNT162b2-Vaccination and Infection History

PurposeTo compare SARS-CoV-2 antigen-specific antibody production and plasma neutralizing capacity against B.1 wild-type-like strain, and Gamma/P.1 and Delta/B.1.617.2 variants-of-concern, in subjects with different Covid-19 disease and vaccination histories.MethodsAdult subjects were: 1) Unvaccinated/hospitalized for Covid-19; 2) Covid-19-recovered followed by one BNT162b2 vaccine dose; and 3) Covid-19-naïve/2-dose BNT162b2 vaccinated. Multiplex Luminex® immunoassays measured IgG, IgA, and IgM plasma levels against SARS-CoV-2 receptor-binding domain (RBD), spike-1 (S), and nucleocapsid proteins. Neutralizing activity was determined in Vero E6 cytopathic assays.ResultsMaximum anti-RBD IgG levels were similar in Covid-19‑recovered individuals 8‒10 days after single-dose vaccination and in Covid-19-naïve subjects 7 days after 2nd vaccine dosing; both groups had ≈2‑fold higher anti-RBD IgG levels than Unvaccinated/Covid-19 subjects tracked through 2 weeks post-symptom onset. Anti-S IgG expression patterns were similar to RBD within each group, but with lower signal strengths. Viral antigen-specific IgA and IgM levels were more variable than IgG patterns. Anti-nucleocapsid immunoglobulins were not detected in Covid-19-naïve subjects. Neutralizing activity against the B.1 strain, and Gamma/P.1 and Delta/B.1.617.2 variants, was highest in Covid‑19-recovered/single-dose vaccinated subjects; although neutralization against the Delta variant in this group was only 26% compared to B.1 neutralization, absolute anti-Delta titers suggested maintained protection. Neutralizing titers against the Gamma and Delta variants were 33‒77% and 26‒67%, respectively, versus neutralization against the B.1 strain (100%) in the three groups.ConclusionThese findings support SARS-CoV-2 mRNA vaccine usefulness regardless of Covid-19 history, and confirm remarkable protection provided by a single vaccine dose in people who have recovered from Covid-19.

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Impact of the N501Y substitution of SARS-CoV-2 Spike on neutralizing monoclonal antibodies targeting diverse epitopes

Virology Journal ◽

10.1186/s12985-021-01554-8 ◽

2021 ◽

Vol 18 (1) ◽

Author(s):

Lin Cheng ◽

Shuo Song ◽

Bing Zhou ◽

Xiangyang Ge ◽

Jiazhen Yu ◽

...

Keyword(s):

Monoclonal Antibodies ◽

Binding Affinity ◽

Neutralizing Antibodies ◽

Therapeutic Antibodies ◽

Wild Type ◽

Neutralization Activity ◽

Neutralizing Activity ◽

Rapid Spread ◽

Global Concern

AbstractThe emergence and rapid spread of the B.1.1.7 lineage (VOC-202012/01) SARS-CoV-2 variant has aroused global concern. The N501Y substitution is the only mutation in the interface between the RBD of B.1.1.7 and ACE2, raising concerns that its recognition by neutralizing antibodies may be affected. Here, we assessed the neutralizing activity and binding affinity of a panel of 12 monoclonal antibodies against the wild type and N501Y mutant SARS-CoV-2 pseudovirus and RBD protein, respectively. We found that the neutralization activity and binding affinity of most detected antibodies (10 out of 12) were unaffected, although the N501Y substitution decreased the neutralizing and binding activities of CB6 and increased that of BD-23. These findings could be of value in the development of therapeutic antibodies.

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LB7. Ad26.COV2.S-Elicted Neutralizing Activities Against SARS-CoV-2 Variants of Concern in Phase 1/2a and Phase 3 Clinical Trials

Open Forum Infectious Diseases ◽

10.1093/ofid/ofab466.1638 ◽

2021 ◽

Vol 8 (Supplement_1) ◽

pp. S804-S805

Author(s):

Mathieu Le Gars ◽

Jerald Sadoff ◽

Mandy Jongeneelen ◽

Dirk Heerwegh ◽

Georgi Shukarev ◽

...

Keyword(s):

Clinical Trials ◽

Single Dose ◽

Phase 1 ◽

Geometric Mean ◽

Wild Type Virus ◽

Original Strain ◽

Wild Type ◽

Serum Samples ◽

Phase 3 ◽

Neutralizing Activity

Abstract Background In a Phase 3 trial, the Janssen COVID-19 vaccine, Ad26.COV2.S, showed robust efficacy against severe–critical COVID-19 in countries where different SARS-CoV-2 variants were circulating. We evaluated Ad26.COV2.S-elicited antibody neutralizing activity against variants of concern (VOC) B.1.1.7 (Alpha), B.1.351 (Beta), and B.1.617.2 (Delta) in sera from participants in clinical trials following a single dose of Ad26.COV2.S. Methods Neutralizing activities of Ad26.COV2.S (given at a dose level of 5 x 1010 viral particles [vp]) against VOC were assessed by wild-type virus neutralizing (wtVNA) and pseudovirion neutralization (psVNA) assays in sera from participants in Phase 1/2a and Phase 3 clinical trials, respectively. Geometric mean titers (GMTs) were determined at Days 29 and 71 after vaccination. Results In serum samples from Phase 1/2a participants (n = 6), at Day 29 after 1 dose of Ad26.COV2.S, wtVNA titers against VOC were lower than for the original strain (GMT = 573), with GMT = 65, 14, and 15 for Alpha, Beta, and Delta, respectively, representing 8.8-, 40.9-, and 37.7-fold decreases. By Day 71 after vaccination (n = 14), fold differences between the original strain (GMT = 375) and VOC (GMT = 113, 27, and 28) were smaller (3.3-, 13.9-, and 13.4-fold) than at Day 29, suggestive of B-cell maturation (Figure 1). Day 71 titers against the Delta variant were maintained for at least 8 months following a single dose of Ad26.COV2.S (5 x 1010 vp). In serum samples from Phase 3 participants (n = 8), psVNA titers against VOC were lower than the original strain at Day 71 after vaccination, with the lowest titers observed for the Beta variant (3.6-fold decrease vs original strain). Smaller reductions in Nab titers for VOC were observed in the psVNA assay compared to wtVNA. Figure 1. Neutralization of B.1.1.7 (Alpha), B.1.351 (Beta), and B.1.617.2 (Delta) lineages in serum samples from participants who received Ad26.COV2.S. n = 6 samples at Day 29 and n = 14 (n = 14 for Alpha and Beta; n = 6 for Delta, comprising the same 6 participants at Day 29) samples at Day 71 after vaccination with a single dose of Ad26.COV2.S (5 x 10^10 vp dose level) were analyzed in wild-type virus neutralization assays against the SARS-CoV-2 Victoria strain (D614, black dots), the B.1.1.7 (Alpha; green dots) the B.1.351 (Beta; blue dots), and the B.1.617.2 (Delta; purple dots) lineages. Dots represent the IC50 (inhibitory concentration) titers per participant. Geometric mean titers (GMTs) and fold decrease in neutralizing activity between the original Victoria strain and each lineage are shown. Conclusion Ad26.COV2.S-elicited serum neutralizing activity against VOC showed an overall decrease in titers relative to the original strain that was largest for the Beta variant, even though vaccine efficacy against severe–critical COVID-19 was maintained in countries where these variants were circulating versus in countries where they were not circulating. Over time, titers against variants increased, suggesting B-cell affinity maturation leading to increasing coverage of VOC. Disclosures Mathieu Le Gars, n/a, Johnson & Johnson (Employee, Shareholder) Jerald Sadoff, MD, Johnson & Johnson (Employee, Shareholder) Mandy Jongeneelen, n/a, Johnson & Johnson (Employee, Shareholder) Dirk Heerwegh, n/a, Janssen Research and Development (Employee) Georgi Shukarev, MD, Janssen (Employee) Carla Truyers, n/a, Janssen Research and Development (Employee) Anne Marit de Groot, n/a, Johnson & Johnson (Employee) Gert Scheper, n/a, Johnson & Johnson (Employee, Shareholder) Jenny Hendriks, n/a, Johnson & Johnson (Employee, Shareholder) Boerries Brandenburg, n/a, Johnson & Johnson (Employee, Shareholder) Frank Struyf, n/a, Johnson & Johnson (Employee, Shareholder) Johan Van Hoof, n/a, Johnson & Johnson (Employee, Shareholder) Macaya Douoguih, MD, MPH, Janssen (Employee) Hanneke Schuitemaker, PhD, Johnson & Johnson (Employee, Shareholder)

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Decline of Humoral Responses against SARS-CoV-2 Spike in Convalescent Individuals

mBio ◽

10.1128/mbio.02590-20 ◽

2020 ◽

Vol 11 (5) ◽

Cited By ~ 14

Author(s):

Guillaume Beaudoin-Bussières ◽

Annemarie Laumaea ◽

Sai Priya Anand ◽

Jérémie Prévost ◽

Romain Gasser ◽

...

Keyword(s):

Neutralizing Antibodies ◽

Receptor Binding Domain ◽

Wild Type ◽

Active Infection ◽

Positive Role ◽

Neutralization Activity ◽

Neutralizing Activity ◽

Specific Igg ◽

Alternative Approaches ◽

Humoral Responses

ABSTRACT In the absence of effective vaccines and with limited therapeutic options, convalescent plasma is being collected across the globe for potential transfusion to coronavirus disease 2019 (COVID-19) patients. The therapy has been deemed safe, and several clinical trials assessing its efficacy are ongoing. While it remains to be formally proven, the presence of neutralizing antibodies is thought to play a positive role in the efficacy of this treatment. Indeed, neutralizing titers of ≥1:160 have been recommended in some convalescent plasma trials for inclusion. Here, we performed repeated analyses at 1-month intervals on 31 convalescent individuals to evaluate how the humoral responses against the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Spike glycoprotein, including neutralization, evolve over time. We observed that the levels of receptor-binding-domain (RBD)-specific IgG and IgA slightly decreased between 6 and 10 weeks after the onset of symptoms but that RBD-specific IgM levels decreased much more abruptly. Similarly, we observed a significant decrease in the capacity of convalescent plasma to neutralize pseudoparticles bearing wild-type SARS-CoV-2 S or its D614G variant. If neutralization activity proves to be an important factor in the clinical efficacy of convalescent plasma transfer, our results suggest that plasma from convalescent donors should be recovered rapidly after resolution of symptoms. IMPORTANCE While waiting for an efficient vaccine to protect against SARS-CoV-2 infection, alternative approaches to treat or prevent acute COVID-19 are urgently needed. Transfusion of convalescent plasma to treat COVID-19 patients is currently being explored; neutralizing activity in convalescent plasma is thought to play a central role in the efficacy of this treatment. Here, we observed that plasma neutralization activity decreased a few weeks after the onset of the symptoms. If neutralizing activity is required for the efficacy of convalescent plasma transfer, our results suggest that convalescent plasma should be recovered rapidly after the donor recovers from active infection.

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Serology study after BTN162b2 vaccination in participants previously infected with SARS-CoV-2 in two different waves versus naïve

Communications Medicine ◽

10.1038/s43856-021-00039-7 ◽

2021 ◽

Vol 1 (1) ◽

Author(s):

Luca Dalle Carbonare ◽

Maria Teresa Valenti ◽

Zeno Bisoffi ◽

Chiara Piubelli ◽

Massimo Pizzato ◽

...

Keyword(s):

Single Dose ◽

Antibody Response ◽

Vaccine Dose ◽

Neutralizing Activity ◽

Serum Neutralization ◽

Iga Antibodies ◽

Antibody Titres ◽

Iga Response ◽

Waning Immunity ◽

Pandemic Wave

Abstract Background The antibody response to SARS-CoV-2 mRNA vaccines in individuals with waning immunity generated by a previous SARS-CoV-2 infection, as well as the patterns of IgA and IgM responses in previously infected and in naïve individuals are still poorly understood. Methods We performed a serology study in a cohort of BTN162b2 mRNA vaccine recipients who were immunologically naïve (N, n = 50) or had been previously infected with SARS-CoV-2 (P.I., n = 51) during the first (n = 25) or second (n = 26) pandemic waves in Italy, respectively. We measured IgG, IgM and IgA antibodies against the SARS-CoV-2 Spike (S) and IgG against the nucleocapsid (N) proteins, as well as the neutralizing activity of sera collected before vaccination, after the first and second dose of vaccine. Results Most P.I. individuals from the first pandemic wave who showed declining antibody titres responded to the first vaccine dose with IgG-S and pseudovirus neutralization titres that were significantly higher than those observed in N individuals after the second vaccine dose. In all recipients, a single dose of vaccine was sufficient to induce a potent IgA response that was not associated with serum neutralization titres. We observed an unconventional pattern of IgM responses that were elicited in only half of immunologically naïve subjects even after the second vaccine dose. Conclusions The response to a single dose of vaccine in P.I. individuals is more potent than that observed in N individuals after two doses. Vaccine-induced IgA are not associated with serum neutralization.

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In vitro neutralizing activity of BNT162b2 mRNA-induced antibodies against full B.1.351 SARS-CoV-2 variant

10.22541/au.163881397.76967489/v1 ◽

2021 ◽

Author(s):

Federico García ◽

Esther Serrano-Conde ◽

Alba Leyva ◽

Ana Fuentes-Lopez ◽

Adolfo de Salazar ◽

...

Keyword(s):

Single Dose ◽

Antibody Response ◽

Neutralizing Antibodies ◽

Healthcare Workers ◽

Neutralizing Antibody ◽

Neutralization Activity ◽

Neutralizing Activity ◽

Study Participants ◽

Prior Infection

Background: SARS-CoV-2 variation represents a serious challenge to current COVID-19 vaccines. Recent reports suggest that B.1.351 and other variants may escape the neutralization activity of the antibodies generated by current vaccines. Methods: Ninety-nine healthcare workers undertaking BNT162b2 mRNA vaccination were sampled at baseline, on the day of the second dose, and 14 days after the latter. Neutralization activity against SARS-CoV-2 B.1, B.1.1.7 and B.1.351 was investigated using a Vero-E6 model. Results: Eleven of the study participants had prior infection with SARS-CoV-2. Neutralization titers against the B.1 and the B.1.1.7 variants were not statistically different and were significantly higher than titers against the B.1.351 variant across pre-exposed and non-pre-exposed vaccinated individuals ( p<0.01). While all vaccinated individuals presented neutralizing antibodies against B.1 and B 1.1.7 after the second dose, 14% were negative against B.1.351, and 76% had low titers (1/20-1/80). Pre-exposed vaccinated individuals showed higher titers than non-pre-exposed after the first (median titers of 1/387 versus 1/28, respectively) and the second doses (1/995 versus 1/703, respectively). As high as 72% of the pre-exposed vaccinees presented titers >1/80 after a single dose, while only 11% of non-exposed vaccinated individuals had titers >1/80. Conclusions: BNT162b2 mRNA-induced antibodies show a lower in vitro neutralizing activity against B.1.351 variant compared to neutralization against B.1.1.7 or B.1 variants. Interestingly, for individuals pre-exposed to SARS-CoV-2, one dose of BNT162b2 mRNA may be adequate to produce neutralizing antibodies against B.1.1.7 and B.1, while two doses of BNT162b2 mRNA provide optimal neutralizing antibody response against B.1.351 too.

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Neutralization of SARS-CoV-2 with IgG from COVID-19-convalescent plasma

Scientific Reports ◽

10.1038/s41598-021-84733-5 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Kenji Maeda ◽

Nobuyo Higashi-Kuwata ◽

Noriko Kinoshita ◽

Satoshi Kutsuna ◽

Kiyoto Tsuchiya ◽

...

Keyword(s):

Immune Response ◽

Clinical Utility ◽

Plasma Sample ◽

Temporal Changes ◽

Rapid Decline ◽

Multiple Endpoints ◽

Neutralization Activity ◽

Neutralizing Activity ◽

Binding Antibody ◽

Potent Immune Response

AbstractWhile there are various attempts to administer COVID-19-convalescent plasmas to SARS-CoV-2-infected patients, neither appropriate approach nor clinical utility has been established. We examined the presence and temporal changes of the neutralizing activity of IgG fractions from 43 COVID-19-convalescent plasmas using cell-based assays with multiple endpoints. IgG fractions from 27 cases (62.8%) had significant neutralizing activity and moderately to potently inhibited SARS-CoV-2 infection in cell-based assays; however, no detectable neutralizing activity was found in 16 cases (37.2%). Approximately half of the patients (~ 41%), who had significant neutralizing activity, lost the neutralization activity within ~ 1 month. Despite the rapid decline of neutralizing activity in plasmas, good amounts of SARS-CoV-2-S1-binding antibodies were persistently seen. The longer exposure of COVID-19 patients to greater amounts of SARS-CoV-2 elicits potent immune response to SARS-CoV-2, producing greater neutralization activity and SARS-CoV-2-S1-binding antibody amounts. The dilution of highly-neutralizing plasmas with poorly-neutralizing plasmas relatively readily reduced neutralizing activity. The presence of good amounts of SARS-CoV-2-S1-binding antibodies does not serve as a surrogate ensuring the presence of good neutralizing activity. In selecting good COVID-19-convalescent plasmas, quantification of neutralizing activity in each plasma sample before collection and use is required.

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Analysis of maxillopedia Expression Pattern and Larval Cuticular Phenotype in Wild-Type and Mutant Tribolium

Genetics ◽

10.1093/genetics/155.2.721 ◽

2000 ◽

Vol 155 (2) ◽

pp. 721-731 ◽

Cited By ~ 7

Author(s):

Teresa D Shippy ◽

Jianhua Guo ◽

Susan J Brown ◽

Richard W Beeman ◽

Robin E Denell

Keyword(s):

Rna Interference ◽

Expression Pattern ◽

Tribolium Castaneum ◽

Expression Patterns ◽

Ectopic Expression ◽

Homeotic Gene ◽

Wild Type ◽

Double Stranded Rna ◽

Similar Expression ◽

Mutant Phenotypes

Abstract The Tribolium castaneum homeotic gene maxillopedia (mxp) is the ortholog of Drosophila proboscipedia (pb). Here we describe and classify available mxp alleles. Larvae lacking all mxp function die soon after hatching, exhibiting strong transformations of maxillary and labial palps to legs. Hypomorphic mxp alleles produce less severe transformations to leg. RNA interference with maxillopedia double-stranded RNA results in phenocopies of mxp mutant phenotypes ranging from partial to complete transformations. A number of gain-of-function (GOF) mxp alleles have been isolated based on transformations of adult antennae and/or legs toward palps. Finally, we have characterized the mxp expression pattern in wild-type and mutant embryos. In normal embryos, mxp is expressed in the maxillary and labial segments, whereas ectopic expression is observed in some GOF variants. Although mxp and Pb display very similar expression patterns, pb null embryos develop normally. The mxp mutant larval phenotype in Tribolium is consistent with the hypothesis that an ancestral pb-like gene had an embryonic function that was lost in the lineage leading to Drosophila.

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

Scientific Reports ◽

10.1038/s41598-021-96143-8 ◽

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.

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Insights into neutralizing antibody responses in individuals exposed to SARS-CoV-2 in Chile

Science Advances ◽

10.1126/sciadv.abe6855 ◽

2021 ◽

Vol 7 (7) ◽

pp. eabe6855 ◽

Cited By ~ 2

Author(s):

Carolina Beltrán-Pavez ◽

Sebastián Riquelme-Barrios ◽

Aarón Oyarzún-Arrau ◽

Aracelly Gaete-Argel ◽

Roxana González-Stegmaier ◽

...

Keyword(s):

General Population ◽

Local Level ◽

Neutralizing Antibody ◽

Host Immunity ◽

Antibody Responses ◽

Wild Type ◽

Neutralization Activity ◽

Future Studies

Chile has one of the worst numbers worldwide in terms of SARS-CoV-2 positive cases and COVID-19–related deaths per million inhabitants; thus, characterization of neutralizing antibody (NAb) responses in the general population is critical to understanding of immunity at the local level. Given our inability to perform massive classical neutralization assays due to the scarce availability of BSL-3 facilities in the country, we developed and fully characterized an HIV-based SARS-CoV-2 pseudotype, which was used in a 96-well plate format to investigate NAb responses in samples from individuals exposed to SARS-CoV-2 or treated with convalescent plasma. We also identified samples with decreased or enhanced neutralization activity against the D614G spike variant compared with the wild type, indicating the relevance of this variant in host immunity. The data presented here represent the first insights into NAb responses in individuals from Chile, serving as a guide for future studies in the country.

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Immunogenicity and Neutralizing Activity Comparison of SARS-CoV-2 Spike Full-Length and Subunit Domain Proteins in Young Adult and Old-Aged Mice

Vaccines ◽

10.3390/vaccines9040316 ◽

2021 ◽

Vol 9 (4) ◽

pp. 316

Author(s):

Ki-Hye Kim ◽

Noopur Bhatnagar ◽

Subbiah Jeeva ◽

Judy Oh ◽

Bo Ryoung Park ◽

...

Keyword(s):

Young Adult ◽

Receptor Binding ◽

Vaccine Dose ◽

The Elderly ◽

Full Length ◽

High Dose ◽

Igg Antibodies ◽

Neutralizing Activity ◽

Aged Mice ◽

Adjuvant Effects

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to be expanding the pandemic disease across the globe. Although SARS-CoV-2 vaccines were rapidly developed and approved for emergency use of vaccination in humans, supply and production difficulties are slowing down the global vaccination program. The efficacy of many different versions of vaccine candidates and adjuvant effects remain unknown, particularly in the elderly. In this study, we compared the immunogenic properties of SARS-CoV-2 full-length spike (S) ectodomain in young adult and aged mice, S1 with receptor binding domain, and S2 with fusion domain. Full-length S was more immunogenic and effective in inducing IgG antibodies after low dose vaccination, compared to the S1 subunit. Old-aged mice induced SARS-CoV-2 spike-specific IgG antibodies with neutralizing activity after high dose S vaccination. With an increased vaccine dose, S1 was highly effective in inducing neutralizing and receptor-binding inhibiting antibodies, although both S1 and S2 subunit domain vaccines were similarly immunogenic. Adjuvant effects were significant for effective induction of IgG1 and IgG2a isotypes, neutralizing and receptor-binding inhibiting antibodies, and antibody-secreting B cell and interferon-γ secreting T cell immune responses. Results of this study provide information in designing SARS-CoV-2 spike vaccine antigens and effective vaccination in the elderly.

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