scholarly journals High individual heterogeneity of neutralizing activities against the original strain and 9 different variants of SARS-CoV-2

2021 ◽  
Author(s):  
Rita Jaafar ◽  
Celine Boschi ◽  
Sarah Aherfi ◽  
Audrey Bancod ◽  
Marion Le Bideau ◽  
...  
Keyword(s):  
South African ◽  
Neutralizing Antibody ◽  
Individual Heterogeneity ◽  
Original Strain ◽  
Indian Isolates

Abstract Since the beginning of the COVID-19 pandemic, several SARS-CoV-2 variants have sequentially emerged. In France, most cases were due to spike D641G-harbouring viruses that descended initially from the Wuhan strain, then by variant of B.1.160 lineage we called Marseille-4 since the summer of 2020, which was followed by the alpha (UK) and beta (South African) variants in early 2021. We determined the neutralizing antibody (nAb) titres in sera from convalescent individuals previously infected by these 4 major local variants and from vaccine recipients to the original Wuhan strain and 9 variants, including two recent circulating delta (Indian) isolates. The results show high interindividual heterogeneity in nAbs, especially according to the variant tested. Unexpectedly, the major variations among nAbs are based on the genotype responsible for the infection. Patients previously infected with the beta and B.1.160 variants had the lowest nAb titres. The highest titres were observed in patients vaccinated with the Pfizer/BioNTech COVID-19 vaccine, even with antibodies against the delta variant.

scholarly journals High individual heterogeneity of neutralizing activities against the original 4 strain and 9 different variants of SARS-CoV-2

2021 ◽  
Author(s):  
Rita Jaafar ◽  
Celine Boschi ◽  
Sarah Aherfi ◽  
Audrey Bancod ◽  
Marion Le Bideau ◽  
...  
Keyword(s):  
South African ◽  
Vaccine Efficacy ◽  
Neutralizing Antibodies ◽  
Neutralizing Antibody ◽  
Spike Protein ◽  
Individual Heterogeneity ◽  
Natural Immunity ◽  
Protein Mutants ◽  
Indian Isolates ◽  
Better Than

Abstract Background. Since the beginning of the COVID-19 pandemic, several SARS-CoV-2 variants have sequentially emerged. In France, most cases were due to spike D641G-harbouring viruses that descended initially from the Wuhan strain, then by variant of B.1.160 lineage we called Marseille-4 since the summer of 2020, which was followed by the alpha (UK) and beta (South African) variants in early 2021, then delta (Indian) now.Methods and Findings. We determined the neutralizing antibody (nAb) titres in sera from convalescent individuals previously infected by these 4 major local variants and from vaccine recipients to the original Wuhan strain and 9 variants, including two recent circulating delta (Indian) isolates. The results show high inter-individual heterogeneity in nAbs, especially according to the variant tested. Unexpectedly, the major variations among nAbs are based on the genotype responsible for the infection. Patients previously infected with the beta and B.1.160 variants had the lowest nAb titres. We show that this heterogeneity is well explained by spike protein mutants modelling using in silico approaches. The highest titres were observed in patients vaccinated with the Pfizer/BioNTech COVID-19 vaccine, even against the delta variant.Conclusions. Immunity acquired naturally after infection is highly dependent on the infecting variant and unexpectedly mRNA-based vaccine efficacy is shown to be often better than natural immunity in eliciting neutralizing antibodies.

scholarly journals Broad neutralization against SARS-CoV-2 variants induced by a modified B.1.351 protein-based COVID-19 vaccine candidate

2021 ◽  
Author(s):  
Danmei Su ◽  
Xinglin Li ◽  
Cui He ◽  
Xueqin Huang ◽  
Meilin Chen ◽  
...  
Keyword(s):  
Immune Responses ◽  
South African ◽  
Immune Escape ◽  
Neutralizing Antibody ◽  
Original Strain ◽  
Humoral Immune ◽  
Humoral Immune Responses ◽  
Antibody Titers ◽  
The Uk ◽  
Immunogenicity Study

Beginning in late 2020, the emergence and spread of multiple variant SARS-CoV-2 strains harboring mutations which may enable immune escape necessitates the rapid evaluation of second generation COVID-19 vaccines, with the goal of inducing optimized immune responses that are broadly protective. Here we demonstrate in a mouse immunogenicity study that two doses of a modified B.1.351 spike (S)-Trimer vaccine (B.1.351 S-Trimer) candidate can induce strong humoral immune responses that can broadly neutralize both the original SARS-CoV-2 strain (Wuhan-Hu-1) and Variants of Concern (VOCs), including the UK variant (B.1.1.7), South African variant (B.1.351) and Brazil variant (P.1). Furthermore, while immunization with two doses (prime-boost) of Prototype S-Trimer vaccine (based on the original SARS-CoV-2 strain) induced lower levels of cross-reactive neutralization against the B.1.351 variant, a third dose (booster) administered with either Prototype S-Trimer or B.1.351 S-Trimer was able to increase neutralizing antibody titers against B.1.351 to levels comparable to neutralizing antibody titers against the original strain elicited by two doses of Prototype S-Trimer.

scholarly journals Serum Neutralizing Activity against B.1.1.7, B.1.351, and P.1 SARS-CoV-2 Variants of Concern in Hospitalized COVID-19 Patients

Viruses ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1347
Author(s):  
Claudia Maria Trombetta ◽  
Serena Marchi ◽  
Simonetta Viviani ◽  
Alessandro Manenti ◽  
Linda Benincasa ◽  
...  
Keyword(s):  
Natural Infection ◽  
Neutralizing Antibody ◽  
Original Strain ◽  
Immune Protection ◽  
Serum Samples ◽  
Symptomatic Infection ◽  
Neutralizing Activity ◽  
The United Kingdom ◽  
Antibody Titers ◽  
Pandemic Wave

The recent spreading of new SARS-CoV-2 variants, carrying several mutations in the spike protein, could impact immune protection elicited by natural infection or conferred by vaccination. In this study, we evaluated the neutralizing activity against the viral variants that emerged in the United Kingdom (B.1.1.7), Brazil (P.1), and South Africa (B.1.351) in human serum samples from hospitalized patients infected by SARS-CoV-2 during the first pandemic wave in Italy in 2020. Of the patients studied, 59.5% showed a decrease (≥2 fold) in neutralizing antibody titer against B.1.1.7, 83.3% against P.1, and 90.5% against B.1.351 with respect to the original strain. The reduction in antibody titers against all analyzed variants, and in particular P.1 and B.1.351, suggests that previous symptomatic infection might be not fully protective against exposure to SARS-CoV-2 variants carrying a set of relevant spike mutations.

scholarly journals A time series forecasting of the proportion of SARS-CoV-2 N501Y lineage in North America

2021 ◽  
Author(s):  
Elena Quinonez ◽  
Majid Vahed ◽  
Abdolrazagh Hashemi Shahraki ◽  
Mehdi Mirsaeidi
Keyword(s):  
Time Series ◽  
North America ◽  
South African ◽  
Neutralizing Antibodies ◽  
Genomic Sequence ◽  
Natural Infection ◽  
Rapid Evolution ◽  
Neutralizing Antibody ◽  
Time Series Forecasting ◽  
Global Database

Introduction: The outbreak of pneumonia known as SARS-COV-2 and newly-emerging South African (B.1.351), the United Kingdom (B.1.1.7) and Brazil (P.1) variants have led to a more infectious virus and potentially more substantial loss of neutralizing activity by natural infection or vaccine-elicited antibodies. Methods: We identified prevalent mutations using the spike receptor-binding domain (S-RBD) of SARS-CoV-2 deposited in the Nextstrain global database and comparing them to the Wuhan-Hu-1/2019 genomic sequence as a reference. Then we calculated the percentages of mutant genomes from the total regional subsample isolates from December 2019 to the end of January 2021. We developed two separate time series forecasting models for the SARS-CoV-2 B.1.1.7 variant. The computational model used the structure of the S-RBD to examine its interactions with the neutralizing antibody, named CV30 (isolated from a patient), and human angiotensin-converting enzyme 2 (hACE-2), based on a hybrid algorithm of template-based modeling to predict the affinity of S protein to the neutralizing antibodies and hACE-2 receptor. Results: The proportion of the B.1.1.7 strain in North America is growing fast. From these computations, it seems that the S-RBD and hACE-2 proteins are less favorable for the South African strain (K417N, E484K, and N501Y) as compared to the wild type structure and more favorable for B.1.1.7 and P.1 variants. In the present of crystallized CV30 neutralizing antibodies, docking scores suggest antibodies can be partially neutralize the B.1.1.7 variant, and, less efficiently, the B.1.351 and P.1 variants. Conclusion: The rapid evolution of SARS-CoV-2 has the potential to allow the newly-emerged B.1.351, and P.1 variants to escape from natural or vaccine-induced neutralizing immunity and viral spreading.

scholarly journals Effect of HIV Envelope Vaccination on the Subsequent Antibody Response to HIV Infection

mSphere ◽  
2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Zanele Ditse ◽  
Nonhlanhla N. Mkhize ◽  
Michael Yin ◽  
Michael Keefer ◽  
David C. Montefiori ◽  
...  
Keyword(s):  
Immune Responses ◽  
Hiv Infection ◽  
South African ◽  
Phase 1 ◽  
Neutralizing Antibody ◽  
Antibody Responses ◽  
Tier 2 ◽  
Subtype C ◽  
Hiv Envelope ◽  
Hiv 1

ABSTRACT Analysis of breakthrough HIV-1 infections could elucidate whether prior vaccination primes relevant immune responses. Here, we measured HIV-specific antibody responses in 14 South African volunteers who acquired HIV infection after participating in phase 1/2 trials of envelope-containing immunogens. Serum samples were collected annually following HIV-1 infection from participants in trials HVTN 073 (subtype C, DNA/MVA, phase 1 trial, n = 1), HVTN 086 (subtype C, DNA/MVA/gp140 protein, phase 1 trial, n = 2), and HVTN 204 (multisubtype, DNA/adenovirus serotype 5 [Ad5], phase 2 trial, n = 7) and 4 placebo recipients. Binding and neutralizing antibody responses to Env proteins and peptides were determined pre- and post-HIV infection using an enzyme-linked immunosorbent assay and the TZM-bl cell neutralization assay, respectively. HIV-infected South African individuals served as unvaccinated controls. Binding antibodies to gp41, V3, V2, the membrane-proximal external region (MPER), and the CD4 binding site were detected from the first year of HIV-1 subtype C infection, and the levels were similar in vaccinated and placebo recipients. Neutralizing antibody responses against tier 1A viruses were detected in all participants, with the highest titers being to a subtype C virus, MW965.26. No responses were observed just prior to infection, indicating that vaccine-primed HIV-specific antibodies had waned. Sporadic neutralization activity against tier 2 isolates was observed after 2 to 3 years of HIV infection, but these responses were similar in the vaccinated and placebo groups as well as the unvaccinated controls. Our data suggest that prior vaccination with these immunogens did not alter the antibody responses to HIV-1 infection, nor did it accelerate the development of HIV neutralization breadth. IMPORTANCE There is a wealth of information on HIV-specific vaccine-induced immune responses among HIV-uninfected participants; however, data on immune responses among participants who acquire HIV after vaccination are limited. Here we show that HIV-specific binding antibody responses in individuals with breakthrough HIV infections were not affected by prior vaccination with HIV envelope-containing immunogens. We also found that these vectored vaccines did not prime tier 2 virus-neutralizing antibody responses, which are thought to be required for prevention against HIV acquisition, or accelerate the development of neutralization breadth. Although this study is limited, such studies can provide insights into whether vaccine-elicited antibody responses are boosted by HIV infection to acquire broader neutralizing activity, which may help to identify antigens relevant to the design of more effective vaccines.

scholarly journals Individuals who were mildly symptomatic following infection with SARS-CoV-2 B.1.1.28 have neutralizing antibodies to the P.1 variant.

2021 ◽  
Author(s):  
Maria Cassia Mendes-Correa ◽  
Lucy Santos Santos Vilas-Boas ◽  
Ana Luiza Bierrenbach ◽  
Anderson Vincente de Paula ◽  
Tania Regina Tozetto-Mendoza ◽  
...  
Keyword(s):  
Antibody Titer ◽  
Neutralizing Antibodies ◽  
Neutralizing Antibody ◽  
Original Strain ◽  
Ancestral Strain

Abstract Objectives: To evaluate if antibodies induced by infection with SARS-CoV-2 B.1.128 neutralize the P.1 variant. Methods: Convalescent sera from 60 individuals who had mild symptoms that did not require hospitalization following a documented SARS-CoV-2 infection (B.1.128 lineage) were assayed for neutralizing antibody titer against their original strain and against the SARS-CoV-2 P.1 variant. Results: Fifty-six (94%) and 50 (84 %) sera were positive for neutralizing antibodies against the ancestral and P.1 strains, respectively, and remained positive throughout the 6-week study period. Neutralization titers were consistently higher against the ancestral strain (p≤ 0.001), but in the majority of patients (57.8%) differences did not differ by more than a single dilution. Conclusions: Neutralizing antibodies that were generated following a mild infection with SARS-CoV-2 B.1.128 were effective in vitro, and likely protective, against the SARS-CoV-2 P.1. variant in the majority of individuals.

scholarly journals Association of Deficiency in Antibody Response to Vaccine and Heterogeneity of Ehrlichia risticii Strains with Potomac Horse Fever Vaccine Failure in Horses

1998 ◽  
Vol 36 (2) ◽  
pp. 506-512 ◽  
Author(s):  
Sukanta K. Dutta ◽  
Ramesh Vemulapalli ◽  
Biswajit Biswas
Keyword(s):  
Antibody Response ◽  
Protective Antigen ◽  
Specific Antigen ◽  
Clinical Signs ◽  
Neutralizing Antibody ◽  
Original Strain ◽  
Vaccine Failure ◽  
Potomac Horse Fever ◽  
Ehrlichia Risticii

Ehrlichia risticii is the causative agent of Potomac horse fever (PHF), which continues to be an important disease of horses. Commercial inactivated whole-cell vaccines are regularly used for immunization of horses against the disease. However, PHF is occurring in large numbers of horses in spite of vaccination. In a limited study, 43 confirmed cases of PHF occurred between the 1994 and 1996 seasons; of these, 38 (89%) were in horses that had been vaccinated for the respective season, thereby clearly indicating vaccine failure. A field study of horses vaccinated with two PHF vaccines indicated a poor antibody response, as determined by immunofluorescence assay (IFA) titers. In a majority of horses, the final antibody titer ranged between 40 and 1,280, in spite of repeated vaccinations. None of the vaccinated horses developed in vitro neutralizing antibody in their sera. Similarly, one horse experimentally vaccinated three times with one of the vaccines showed a poor antibody response, with final IFA titers between 80 and 160. The horse did not develop in vitro neutralizing antibody or antibody against the 50/85-kDa strain-specific antigen (SSA), which is the protective antigen of the original strain, 25-D, and the variant strain of our laboratory, strain 90-12. Upon challenge infection with the 90-12 strain, the horse showed clinical signs of the disease. The horse developed neutralizing antibody and antibody to the 50/85-kDa SSA following the infection. Studies of the new E. risticiiisolates from the field cases indicated that they were heterogeneous among themselves and showed differences from the 25-D and 90-12 strains as determined by IFA reactivity pattern, DNA amplification finger printing profile, and in vitro neutralization activity. Most importantly, the molecular sizes of the SSA of these isolates varied, ranging from 48 to 85 kDa. These studies suggest that the deficiency in the antibody response to the PHF vaccines and the heterogeneity ofE. risticii isolates may be associated with the vaccine failure.

scholarly journals Reduced binding and neutralization of infection- and vaccine-induced antibodies to the B.1.351 (South African) SARS-CoV-2 variant

2021 ◽  
Author(s):  
Venkata Viswanadh Edara ◽  
Carson Norwood ◽  
Katharine Floyd ◽  
Lilin Lai ◽  
Meredith E. Davis-Gardner ◽  
...  
Keyword(s):  
South African ◽  
Receptor Binding ◽  
Symptom Onset ◽  
Protective Immunity ◽  
Neutralizing Antibody ◽  
Spike Protein ◽  
Receptor Binding Domain ◽  
Live Virus ◽  
Fold Reduction ◽  
Antibody Titers

SUMMARYThe emergence of SARS-CoV-2 variants with mutations in the spike protein is raising concerns about the efficacy of infection- or vaccine-induced antibodies to neutralize these variants. We compared antibody binding and live virus neutralization of sera from naturally infected and spike mRNA vaccinated individuals against a circulating SARS-CoV-2 B.1 variant and the emerging B.1.351 variant. In acutely-infected (5-19 days post-symptom onset), convalescent COVID-19 individuals (through 8 months post-symptom onset) and mRNA-1273 vaccinated individuals (day 14 post-second dose), we observed an average 4.3-fold reduction in antibody titers to the B.1.351-derived receptor binding domain of the spike protein and an average 3.5-fold reduction in neutralizing antibody titers to the SARS-CoV-2 B.1.351 variant as compared to the B.1 variant (spike D614G). However, most acute and convalescent sera from infected and all vaccinated individuals neutralize the SARS-CoV-2 B.1.351 variant, suggesting that protective immunity is retained against COVID-19.

scholarly journals XAV-19, a Swine Glyco-Humanized Polyclonal Antibody Against SARS-CoV-2 Spike Receptor-Binding Domain, Targets Multiple Epitopes and Broadly Neutralizes Variants

2021 ◽  
Vol 12 ◽  
Author(s):  
Bernard Vanhove ◽  
Stéphane Marot ◽  
Ray T. So ◽  
Benjamin Gaborit ◽  
Gwénaëlle Evanno ◽  
...  
Keyword(s):  
South African ◽  
Receptor Binding ◽  
Polyclonal Antibodies ◽  
Neutralizing Antibody ◽  
Binding Domain ◽  
Spike Protein ◽  
Receptor Binding Domain ◽  
Live Virus ◽  
Angiotensin Converting Enzyme 2 ◽  
The United Kingdom

Amino acid substitutions and deletions in the Spike protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants can reduce the effectiveness of monoclonal antibodies (mAbs). In contrast, heterologous polyclonal antibodies raised against S protein, through the recognition of multiple target epitopes, have the potential to maintain neutralization capacities. XAV-19 is a swine glyco-humanized polyclonal neutralizing antibody raised against the receptor binding domain (RBD) of the Wuhan-Hu-1 Spike protein of SARS-CoV-2. XAV-19 target epitopes were found distributed all over the RBD and particularly cover the receptor binding motives (RBMs), in direct contact sites with the angiotensin converting enzyme-2 (ACE-2). Therefore, in Spike/ACE-2 interaction assays, XAV-19 showed potent neutralization capacities of the original Wuhan Spike and of the United Kingdom (Alpha/B.1.1.7) and South African (Beta/B.1.351) variants. These results were confirmed by cytopathogenic assays using Vero E6 and live virus variants including the Brazil (Gamma/P.1) and the Indian (Delta/B.1.617.2) variants. In a selective pressure study on Vero E6 cells conducted over 1 month, no mutation was associated with the addition of increasing doses of XAV-19. The potential to reduce viral load in lungs was confirmed in a human ACE-2 transduced mouse model. XAV-19 is currently evaluated in patients hospitalized for COVID-19-induced moderate pneumonia in phase 2a-2b (NCT04453384) where safety was already demonstrated and in an ongoing 2/3 trial (NCT04928430) to evaluate the efficacy and safety of XAV-19 in patients with moderate-to-severe COVID-19. Owing to its polyclonal nature and its glyco-humanization, XAV-19 may provide a novel safe and effective therapeutic tool to mitigate the severity of coronavirus disease 2019 (COVID-19) including the different variants of concern identified so far.

scholarly journals Thermodynamics and Kinetics in Antibody Resistance of the 501Y.V2 SARS-CoV-2 Variant

2021 ◽  
Author(s):  
Son Tung Ngo ◽  
Trung Hai Nguyen ◽  
Duc-Hung Pham ◽  
Nguyen Thanh Tung ◽  
Pham Cam Nam
Keyword(s):  
Free Energy ◽  
South African ◽  
Binding Free Energy ◽  
Energy Landscape ◽  
Neutralizing Antibody ◽  
Receptor Binding Domain ◽  
The South ◽  
Thermodynamics And Kinetics ◽  
Antibody Resistance ◽  
Kinetics Of

Understanding thermodynamics and kinetics of the binding process of antibody to SARS-CoV-2 receptor-binding domain (RBD) of Spike protein is very important for the development of COVID19 vaccines. Especially, it is essential to understand how the binding mechanism may change under the effects of RBD mutations. In this context, we have demonstrated that the South African variant (B1.351 or 501Y.V2) can resist the neutralizing antibody (NAb). Three substitutions in RBD including K417N, E484K, and N501Y alters the free energy landscape, binding pose, binding free energy, binding kinetics, and unbinding pathway of RBD + NAb complexes. The low binding affinity of NAb to 501Y.V2 RBD confirms the antibody resistance of the South African variant.

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