scholarly journals mRNA Vaccine-Induced Antibodies More Effective than Natural Immunity in Neutralizing SARS-CoV-2 and its High Affinity Variants

2021 ◽  
Author(s):  
Yunkai Yu ◽  
Dominic Esposito ◽  
Zhigang Kang ◽  
Jianming Lu ◽  
Alan Remaley ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Similar Degree ◽  
Natural Immunity ◽  
Receptor Binding Domain ◽  
Blood Samples ◽  
High Affinity ◽  
Functional Assays ◽  
Highly Effective ◽  
Antibody Levels ◽  
Neutralization Ability

Abstract Several variants of SARS-CoV-2 have emerged. Those with mutations in the angiotensin-converting enzyme (ACE2) receptor binding domain (RBD) are associated with increased transmission and severity. In this study, we developed both antibody quantification and functional assays. Analyses of both COVID-19 convalescent and diagnostic cohorts strongly support the use of RBD antibody levels as an excellent surrogate to biochemical neutralization activities. Data further revealed that the samples from mRNA vaccinated individuals had a median of 17 times higher RBD antibody levels and a similar degree of increased neutralization activities against RBD-ACE2 binding than those from natural infections. Our data showed that N501Y RBD had 5-fold higher ACE2 binding than the original variant. While antisera from naturally infected subjects had substantially reduced neutralization ability against N501Y RBD, all blood samples from vaccinated individuals were highly effective in neutralizing it. Thus, our data indicates that mRNA vaccination is far more effective than natural immunity in generating highly effective neutralizing antibodies. It further suggests a potential need to maintain high RBD antibody levels to control the more infectious SARS-CoV-2 variants.

scholarly journals A Rapid and Efficient Screening System for Neutralizing Antibodies and Its Application for SARS-CoV-2

2021 ◽  
Vol 12 ◽  
Author(s):  
Xiaojian Han ◽  
Yingming Wang ◽  
Shenglong Li ◽  
Chao Hu ◽  
Tingting Li ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Inhibitory Concentration ◽  
Function Analysis ◽  
Screening Method ◽  
Emerging Infectious Diseases ◽  
Receptor Binding Domain ◽  
Blood Samples ◽  
High Affinity ◽  
And Function ◽  
Efficient Screening

After the pandemic of COVID-19, neutralizing antibodies (NAbs) against SARS-CoV-2 have been developed for the prophylactic and therapeutic purposes. However, few methodologies are described in detail on how to rapidly and efficiently generate effective NAbs to SARS-CoV-2. Here, we integrated and optimized a strategically screening method for NAbs, which has enabled us to obtain SARS-CoV-2 receptor-binding domain (RBD) specific NAbs within 6 days, followed by additional 9 days for antibody production and function analysis. Using this method, we obtained 198 specific Abs against SARS-CoV-2 RBD from the blood samples of COVID-19 convalescent patients, and 96 of them showed neutralizing activity. At least 20% of these NAbs exhibited advanced neutralizing potency and high affinity, with the top two NAbs showing half-maximal inhibitory concentration (IC50) to block authentic SARS-CoV-2 at 9.88 and 11.13 ng/ml, respectively. Altogether, our study provides an effective methodology with high applicable value for discovering potential preventative and therapeutic NAbs for the emerging infectious diseases.

scholarly journals Use of Quantitative Dried Blood Spots to Evaluate the Post-Vaccination Level of Neutralizing Antibodies against SARS-CoV-2

Life ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1125
Author(s):  
Alexandre Marchand ◽  
Ingrid Roulland ◽  
Florian Semence ◽  
Olof Beck ◽  
Magnus Ericsson
Keyword(s):  
Neutralizing Antibodies ◽  
Immune Status ◽  
Clinical Chemistry ◽  
Venous Blood ◽  
Dried Blood Spots ◽  
Post Vaccination ◽  
Blood Samples ◽  
Antibody Levels ◽  
Blood Spot ◽  
Over Time

To combat the COVID-19 pandemic, vaccines against SARS-CoV-2 are now given to protect populations worldwide. The level of neutralizing antibodies following the vaccination will evolve with time and vary between individuals. Immunoassays quantifying immunoglobulins against the viral spike (S) protein in serum/plasma have been developed, but the need for venous blood samples could limit the frequency and scale of control in populations. The use of a quantitative dried blood spot (DBS) that can be self-collected would simplify this monitoring. The objective of this study was to determine whether a quantitative DBS device (Capitainer qDBS 10 µL) could be used in combination with an Elecsys anti-SARS-CoV-2 S immunoassay from Roche to follow the development and persistence of anti-S antibodies. This objective was carried out through two clinical studies. The first study investigated 14 volunteers who received two doses of the Comirnaty (Pfizer) vaccine. The levels of anti-S antibodies and the progression over time post-vaccination were studied for three months. The level of produced antibodies varied between subjects, but a similar trend was observed. The anti-S antibodies were highly stimulated by the second dose (×100) and peaked two weeks later. The antibody levels subsequently decreased and three months later were down to 65%. DBS proved to be sufficiently sensitive for use in evaluating the immune status against SARS-CoV-2 over a prolonged time. The second cohort was composed of 200 random patients from a clinical chemistry department in Stockholm. In this cohort, we had no information on previous COVID-19 infections or vaccination. Nevertheless, 87% of the subjects had anti-S immunoglobulins over 0.8 U/mL, and the bias between plasma and DBS proved to be variable, as was also seen in the first vaccination study.

scholarly journals A rapid and efficient screening system for neutralizing antibodies and its application for SARS-CoV-2

2020 ◽  
Author(s):  
Xiaojian Han ◽  
Yingming Wang ◽  
Shenglong Li ◽  
Chao Hu ◽  
Tingting Li ◽  
...  
Keyword(s):  
Receptor Binding ◽  
Neutralizing Antibodies ◽  
Inhibitory Concentration ◽  
Screening Method ◽  
Emerging Infectious Diseases ◽  
Receptor Binding Domain ◽  
Screening System ◽  
Blood Samples ◽  
Therapeutic Value ◽  
Efficient Screening

Abstract After the epidemic of COVID-19, neutralizing antibodies (NAbs) against SARS-CoV-2 has been developed for the preventative and therapeutic purposes. However, few methodologies are reported in detail on how to rapidly and efficiently generate NAbs of interest. Here, we present a strategically optimized screening method for NAbs, which has enabled us to obtain SARS-CoV-2 receptor-binding domain (RBD) specific monoclonal Abs within 4 days, followed by additional 2 days to evaluate their neutralizing activities. Using this method, we obtained 198 specific Abs against SARS-CoV-2 RBD from the blood samples of COVID-19 convalescent patients, and 96 of them showed neutralizing activity. At least 20% of these NAbs exhibited high neutralizing potency. The top 2 NAbs showed the half-maximal inhibitory concentration (IC50) to block authentic SARS-CoV-2 at 9.88 and 11.13 ng/ml, respectively. Altogether, our study provides a fundamental methodology for discovering NAbs with potential preventative and therapeutic value for emerging infectious diseases.

scholarly journals A Retrospective Survey among SARS-CoV-1 Infected Healthcare Workers after Three Years Post-Infection

Pathogens ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1078
Author(s):  
Szu-Wei Huang ◽  
Aspiro Nayim Urbina ◽  
Yi-Ming Arthur Chen ◽  
Sheng-Fan Wang
Keyword(s):  
Statistical Analysis ◽  
Post Infection ◽  
Neutralizing Antibodies ◽  
Healthcare Workers ◽  
Blood Samples ◽  
Retrospective Survey ◽  
Factors Affecting ◽  
Factors Associated ◽  
Neutralization Ability

Healthcare workers (HCWs) are on the frontline fighting several infectious diseases including SARS-CoV-1 and COVID-19. Coronavirus neutralizing antibodies (nAbs) were recently reported to last for a certain period. The factors affecting nAbs’ existence remain unclear. Here, we retrospectively analyzed the factors correlating with nAbs’ from SARS-CoV-1 long-term convalescence HCWs in Taiwan. One hundred and thirty SARS-CoV-1 convalescent patients were recruited between August 2006 and March 2007. Blood samples were collected to determine the anti-nucleocapsid (N) and anti-spike (S) antibodies’ existence status and neutralization ability. Neutralization ability was measured using SARS-CoV-1 pseudotyped viruses. Statistical analysis of factors associated with anti-SARS-CoV-1 antibodies’ existence status was determined using SAS software. 46.2% SARS-CoV-1 convalescent patients presented anti-N antibody after three years post-infection. Among sixty participants, ten participants co-presented anti-S antibodies. Eight participants with anti-S antibody displayed neutralization ability to SARS-CoV-1. The gender, age, and disease severity of participants did not affect the anti-N antibody existence status, whereas the anti-S antibody is significantly reduced in participants with old age (>50 years, p = 0.0434) after three years post SARS-CoV-1 infection. This study suggests that age is an important factor correlated with the duration of SARS-CoV-1 protective antibody existence status.

scholarly journals Seasonal Betacoronavirus Antibodies’ Expansion Post-BNT161b2 Vaccination Associates with Reduced SARS-CoV-2 VoC Neutralization

2022 ◽  
Author(s):  
Stefania Dispinseri ◽  
Ilaria Marzinotto ◽  
Cristina Brigatti ◽  
Maria Franca Pirillo ◽  
Monica Tolazzi ◽  
...  
Keyword(s):  
Health Care ◽  
Health Care Workers ◽  
Neutralizing Antibodies ◽  
Spike Protein ◽  
Post Vaccination ◽  
Care Workers ◽  
Sequential Samples ◽  
Alpha Beta ◽  
Antibody Levels ◽  
Neutralization Ability

AbstractSARS-CoV-2 vaccination is known to induce antibodies that recognize also variants of concerns (VoCs) of the virus. However, epidemiological and laboratory evidences indicate that these antibodies have a reduced neutralization ability against VoCs. We studied binding and neutralizing antibodies against the Spike protein domains and subunits of the Wuhan-Hu-1 virus and its alpha, beta, delta VoCs and of seasonal betacoronaviruses (HKU1 and OC43) in a cohort of 31 health care workers prospectively followed post-vaccination with BNT162b2-Comirnaty. The study of sequential samples collected up to 64 days post-vaccination showed that serological assays measuring IgG against Wuhan-Hu-1 antigens were a poor proxy for VoC neutralization. In addition, in subjects who had asymptomatic or mild COVID-19 prior to vaccination, the loss of nAbs following disease could be rapid and accompanied by post-vaccination antibody levels similar to those of naïve vaccinees. Interestingly, in health care workers naïve for SARS-CoV-2 infection, vaccination induced a rapid and transient reactivation of pre-existing seasonal coronaviruses IgG responses that was associated with a subsequent reduced ability to neutralize alpha and beta VoCs.

scholarly journals An Ultrapotent Neutralizing Bispecific Antibody with Broad Spectrum Against SARS-CoV-2 Variants

2021 ◽  
Author(s):  
Hui Zhang ◽  
Haohui Huang ◽  
Rong Li ◽  
Lu Zhang ◽  
Zhiwei Wang ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Bispecific Antibody ◽  
Herd Immunity ◽  
Therapeutic Effects ◽  
Bodyweight Loss ◽  
Receptor Binding Domain ◽  
Single Administration ◽  
Converting Enzyme ◽  
Angiotensin Converting Enzyme 2 ◽  
High Affinity

Abstract Some variants of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) are threatening our global efforts of herd immunity, novel and more efficacious agents are urgently needed. We have developed a bispecific antibody, 2022, which bonds with high affinity to two non-overlapping epitopes on the receptor-binding domain (RBD) simultaneously, blocks the binding of RBD to human angiotensin-converting enzyme 2 (ACE2), and potently neutralizes SARS-CoV-2 and all of the variants tested, including variants carrying mutations known to resist neutralizing antibodies approved under Emergency Use Authorization (EUA) and reduce the efficacy of existing vaccines. In a mouse model of SARS-CoV-2, 2022 showed strong prophylactic and therapeutic effects. A single administration of 2022 completely protected all mice from bodyweight loss, as compared with up to 20% loss of bodyweight in placebo treated mice, reduced the lung viral titers to undetectable in all mice treated with 2022 either prophylactically or therapeutically, as compared with around 1X105 pfu/g lung tissue in placebo treated mice. In summary, bispecific antibody 2022 showed potent binding and neutralizing activity across a variety of SARS-CoV-2 variants and could be an attractive weapon to combat the ongoing waves of the COVID-19 pandemic.

scholarly journals High genetic barrier to escape from human polyclonal SARS-CoV-2 neutralizing antibodies

2021 ◽  
Author(s):  
Fabian Schmidt ◽  
Yiska Weisblum ◽  
Magdalena Rutkowska ◽  
Daniel Poston ◽  
Justin Da Silva ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Polyclonal Antibodies ◽  
Viral Escape ◽  
Similar Degree ◽  
Receptor Binding Domain ◽  
Genetic Barrier ◽  
Viral Receptor ◽  
Naturally Occurring ◽  
Complete Resistance ◽  
Neutralizing Epitopes

The number and variability of the neutralizing epitopes targeted by polyclonal antibodies in SARS-CoV-2 convalescent and vaccinated individuals are key determinants of neutralization breadth and, consequently, the genetic barrier to viral escape. Using chimeric viruses and antibody-selected viral mutants, we show that multiple neutralizing epitopes, within and outside the viral receptor binding domain (RBD), are variably targeted by polyclonal plasma antibodies and coincide with sequences that are enriched for diversity in natural SARS-CoV-2 populations. By combining plasma-selected spike substitutions, we generated synthetic polymutant spike proteins that resisted polyclonal antibody neutralization to a similar degree as currently circulating variants of concern (VOC). Importantly, by aggregating VOC-associated and plasma-selected spike substitutions into a single polymutant spike protein, we show that 20 naturally occurring mutations in SARS-CoV-2 spike are sufficient to confer near-complete resistance to the polyclonal neutralizing antibodies generated by convalescents and mRNA vaccine recipients. Strikingly however, plasma from individuals who had been infected and subsequently received mRNA vaccination, neutralized this highly resistant SARS-CoV-2 polymutant, and also neutralized diverse sarbecoviruses. Thus, optimally elicited human polyclonal antibodies against SARS-CoV-2 should be resilient to substantial future SARS-CoV-2 variation and may confer protection against future sarbecovirus pandemics.

scholarly journals A high-affinity RBD-targeting nanobody improves fusion partner’s potency against SARS-CoV-2

2021 ◽  
Vol 17 (3) ◽  
pp. e1009328
Author(s):  
Hebang Yao ◽  
Hongmin Cai ◽  
Tingting Li ◽  
Bingjie Zhou ◽  
Wenming Qin ◽  
...  
Keyword(s):  
Receptor Binding ◽  
Neutralizing Antibodies ◽  
Binding Motif ◽  
Fusion Partner ◽  
Receptor Binding Domain ◽  
Single Chain ◽  
Neutralization Activity ◽  
Effective Strategies ◽  
High Affinity ◽  
Considerable Research

A key step to the SARS-CoV-2 infection is the attachment of its Spike receptor-binding domain (S RBD) to the host receptor ACE2. Considerable research has been devoted to the development of neutralizing antibodies, including llama-derived single-chain nanobodies, to target the receptor-binding motif (RBM) and to block ACE2-RBD binding. Simple and effective strategies to increase potency are desirable for such studies when antibodies are only modestly effective. Here, we identify and characterize a high-affinity synthetic nanobody (sybody, SR31) as a fusion partner to improve the potency of RBM-antibodies. Crystallographic studies reveal that SR31 binds to RBD at a conserved and ‘greasy’ site distal to RBM. Although SR31 distorts RBD at the interface, it does not perturb the RBM conformation, hence displaying no neutralizing activities itself. However, fusing SR31 to two modestly neutralizing sybodies dramatically increases their affinity for RBD and neutralization activity against SARS-CoV-2 pseudovirus. Our work presents a tool protein and an efficient strategy to improve nanobody potency.

scholarly journals Discovery and characterization of high-affinity, potent SARS-CoV-2 neutralizing antibodies via single B cell screening

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
John S. Schardt ◽  
Ghasidit Pornnoppadol ◽  
Alec A. Desai ◽  
Kyung Soo Park ◽  
Jennifer M. Zupancic ◽  
...  
Keyword(s):  
B Cell ◽  
Receptor Binding ◽  
Neutralizing Antibodies ◽  
Binding Domain ◽  
Receptor Binding Domain ◽  
High Affinity ◽  
Mechanistic Investigation ◽  
Wide Range ◽  
Novel Coronavirus

AbstractMonoclonal antibodies that target SARS-CoV-2 with high affinity are valuable for a wide range of biomedical applications involving novel coronavirus disease (COVID-19) diagnosis, treatment, and prophylactic intervention. Strategies for the rapid and reliable isolation of these antibodies, especially potent neutralizing antibodies, are critical toward improved COVID-19 response and informed future response to emergent infectious diseases. In this study, single B cell screening was used to interrogate antibody repertoires of immunized mice and isolate antigen-specific IgG1+ memory B cells. Using these methods, high-affinity, potent neutralizing antibodies were identified that target the receptor-binding domain of SARS-CoV-2. Further engineering of the identified molecules to increase valency resulted in enhanced neutralizing activity. Mechanistic investigation revealed that these antibodies compete with ACE2 for binding to the receptor-binding domain of SARS-CoV-2. These antibodies may warrant further development for urgent COVID-19 applications. Overall, these results highlight the potential of single B cell screening for the rapid and reliable identification of high-affinity, potent neutralizing antibodies for infectious disease applications.

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