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1.
Trials ; 23(1): 263, 2022 Apr 05.
Article in English | MEDLINE | ID: covidwho-1779666

ABSTRACT

BACKGROUND: Antiretroviral therapy (ART) has led to dramatic improvements in survival for people living with HIV, but is unable to cure infection, or induce viral control off therapy. Designing intervention trials with novel agents with the potential to confer a period of HIV remission without ART remains a key scientific and community goal. We detail the rationale, design, and outcomes of a randomised, placebo-controlled trial of two HIV-specific long-acting broadly neutralising antibodies (bNAbs): 3BNC117-LS and 10-1074-LS, which target CD4 binding site and V3 loop respectively, on post-treatment viral control. METHODS: RIO is a randomised, placebo-controlled, double-blinded prospective phase II study. Eligible individuals will have started ART within 3 months of primary HIV infection and have viral sequences that appear to be sensitive to both bNAbs. It will randomise 72 eligible participants 1:1 to the following arms via a two-stage design. In Stage 1, arm A participants are given dual long-acting (LS-variants) bNAbs infusions, followed by intensively monitored Analytical Treatment Interruption (ATI) (n = 36); in arm B, participants receive placebo infusions followed by ATI. The primary endpoint will be time to viral rebound within 36 weeks after ATI. Upon viral rebound, the participant and researcher are unblinded. Participants in arm A recommence ART and complete the study. Participants in arm B are invited to restart ART and enroll into Stage 2 where they will receive open-label LS bNAbs, followed by a second ATI 24 weeks after. Secondary and exploratory endpoints include adverse events, time to undetectable viraemia after restarting ART, immunological markers, HIV proviral DNA, serum bNAb concentrations in blood, bNAb resistance at viral rebound, and quality of life measures. DISCUSSION: The two-stage design was determined in collaboration with community involvement. This design allows all participants the option to receive bNAbs. It also tests the hypothesis that bNAbs may drive sustained HIV control beyond the duration of detectable bNAb concentrations. Community representatives were involved at all stages. This included the two-stage design, discussion on the criteria to restart ART, frequency of monitoring visits off ART, and reducing the risk of onward transmission to HIV-negative partners. It also included responding to the challenges of COVID-19. TRIAL REGISTRATION: The protocol is registered on Clinical. TRIALS: gov and EudraCT and has approval from UK Ethics and MHRA.


Subject(s)
COVID-19 , HIV Infections , HIV-1 , Broadly Neutralizing Antibodies , Clinical Trials, Phase II as Topic , Community Participation , HIV Antibodies , HIV Infections/diagnosis , HIV Infections/drug therapy , Humans , Prospective Studies , Quality of Life , Randomized Controlled Trials as Topic , SARS-CoV-2 , Treatment Outcome
2.
Immunity ; 2022.
Article in English | ScienceDirect | ID: covidwho-1778212

ABSTRACT

Summary SARS-CoV-2 infection or vaccination produces neutralizing antibody responses that contribute to better clinical outcomes. The receptor binding domain (RBD) and the N-terminal domain (NTD) of the spike trimer (S) constitute the two major neutralizing targets for antibodies. Here, we use NTD-specific probes to capture anti-NTD memory B cells in a longitudinal cohort of infected individuals, some of whom were vaccinated. We found 6 complementation groups of neutralizing antibodies. 58% targeted epitopes outside the NTD supersite, 58% neutralized either Gamma or Omicron, and 14% were broad neutralizers that also neutralized Omicron. Structural characterization revealed that broadly active antibodies targeted three epitopes outside the NTD supersite including a class that recognized both the NTD and SD2 domain. Rapid recruitment of memory B cells producing these antibodies into the plasma cell compartment upon re-infection likely contributes to the relatively benign course of subsequent infections with SARS-CoV-2 variants, including Omicron.

5.
Nature ; 600(7889): 517-522, 2021 12.
Article in English | MEDLINE | ID: covidwho-1454790

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection produces B cell responses that continue to evolve for at least a year. During that time, memory B cells express increasingly broad and potent antibodies that are resistant to mutations found in variants of concern1. As a result, vaccination of coronavirus disease 2019 (COVID-19) convalescent individuals with currently available mRNA vaccines produces high levels of plasma neutralizing activity against all variants tested1,2. Here we examine memory B cell evolution five months after vaccination with either Moderna (mRNA-1273) or Pfizer-BioNTech (BNT162b2) mRNA vaccine in a cohort of SARS-CoV-2-naive individuals. Between prime and boost, memory B cells produce antibodies that evolve increased neutralizing activity, but there is no further increase in potency or breadth thereafter. Instead, memory B cells that emerge five months after vaccination of naive individuals express antibodies that are similar to those that dominate the initial response. While individual memory antibodies selected over time by natural infection have greater potency and breadth than antibodies elicited by vaccination, the overall neutralizing potency of plasma is greater following vaccination. These results suggest that boosting vaccinated individuals with currently available mRNA vaccines will increase plasma neutralizing activity but may not produce antibodies with equivalent breadth to those obtained by vaccinating convalescent individuals.


Subject(s)
COVID-19 Vaccines/immunology , Evolution, Molecular , Spike Glycoprotein, Coronavirus/immunology , Vaccines, Synthetic/immunology , /immunology , /immunology , Adult , Aged , Antibodies, Monoclonal/immunology , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , Antibody Affinity , Cohort Studies , Cross Reactions , Enzyme-Linked Immunosorbent Assay , Epitopes, B-Lymphocyte/immunology , Female , Humans , Male , Middle Aged , Neutralization Tests , Protein Domains/immunology , Spike Glycoprotein, Coronavirus/chemistry , Young Adult
6.
Nature ; 600(7889): 512-516, 2021 12.
Article in English | MEDLINE | ID: covidwho-1428879

ABSTRACT

The number and variability of the neutralizing epitopes targeted by polyclonal antibodies in individuals who are SARS-CoV-2 convalescent and vaccinated are key determinants of neutralization breadth and the genetic barrier to viral escape1-4. Using HIV-1 pseudotypes and plasma selection experiments with vesicular stomatitis virus/SARS-CoV-2 chimaeras5, here we show that multiple neutralizing epitopes, within and outside the receptor-binding domain, are variably targeted by human polyclonal antibodies. Antibody targets coincide with spike sequences that are enriched for diversity in natural SARS-CoV-2 populations. By combining plasma-selected spike substitutions, we generated synthetic 'polymutant' spike protein pseudotypes that resisted polyclonal antibody neutralization to a similar degree as circulating variants of concern. By aggregating variant of concern-associated and antibody-selected spike substitutions into a single polymutant spike protein, we show that 20 naturally occurring mutations in the SARS-CoV-2 spike protein are sufficient to generate pseudotypes with near-complete resistance to the polyclonal neutralizing antibodies generated by individuals who are convalescent or recipients who received an mRNA vaccine. However, plasma from individuals who had been infected and subsequently received mRNA vaccination neutralized pseudotypes bearing this highly resistant SARS-CoV-2 polymutant spike, or diverse sarbecovirus spike proteins. 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 potential future sarbecovirus pandemics.


Subject(s)
Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , Immune Evasion , Immune Sera/immunology , Mutation , SARS-CoV-2/genetics , SARS-CoV-2/immunology , COVID-19/immunology , COVID-19/prevention & control , COVID-19/virology , Convalescence , Cross Reactions , Humans , Neutralization Tests , SARS-CoV-2/isolation & purification , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/immunology
7.
Cell Rep ; 36(13): 109760, 2021 09 28.
Article in English | MEDLINE | ID: covidwho-1401299

ABSTRACT

Many anti-severe acute respiratory syndrome coronavirus 2 (anti-SARS-CoV-2) neutralizing antibodies target the angiotensin-converting enzyme 2 (ACE2) binding site on viral spike receptor-binding domains (RBDs). Potent antibodies recognize exposed variable epitopes, often rendering them ineffective against other sarbecoviruses and SARS-CoV-2 variants. Class 4 anti-RBD antibodies against a less-exposed, but more-conserved, cryptic epitope could recognize newly emergent zoonotic sarbecoviruses and variants, but they usually show only weak neutralization potencies. Here, we characterize two class 4 anti-RBD antibodies derived from coronavirus disease 2019 (COVID-19) donors that exhibit breadth and potent neutralization of zoonotic coronaviruses and SARS-CoV-2 variants. C118-RBD and C022-RBD structures reveal orientations that extend from the cryptic epitope to occlude ACE2 binding and CDRH3-RBD main-chain H-bond interactions that extend an RBD ß sheet, thus reducing sensitivity to RBD side-chain changes. A C118-spike trimer structure reveals rotated RBDs that allow access to the cryptic epitope and the potential for intra-spike crosslinking to increase avidity. These studies facilitate vaccine design and illustrate potential advantages of class 4 RBD-binding antibody therapeutics.


Subject(s)
Broadly Neutralizing Antibodies/immunology , COVID-19/immunology , SARS-CoV-2/immunology , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , Binding Sites/immunology , Broadly Neutralizing Antibodies/pharmacology , Cross Reactions , Epitopes/metabolism , Humans , Protein Binding , Protein Interaction Domains and Motifs , Receptors, Virus/metabolism , SARS-CoV-2/pathogenicity , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/immunology
8.
J Exp Med ; 218(4)2021 04 05.
Article in English | MEDLINE | ID: covidwho-1387677

ABSTRACT

SARS-CoV-2 is responsible for an ongoing pandemic that has affected millions of individuals around the globe. To gain further understanding of the immune response in recovered individuals, we measured T cell responses in paired samples obtained an average of 1.3 and 6.1 mo after infection from 41 individuals. The data indicate that recovered individuals show persistent polyfunctional SARS-CoV-2 antigen-specific memory that could contribute to rapid recall responses. Recovered individuals also show enduring alterations in relative overall numbers of CD4+ and CD8+ memory T cells, including expression of activation/exhaustion markers, and cell division.


Subject(s)
COVID-19/immunology , COVID-19/virology , Host-Pathogen Interactions/immunology , Immunity, Cellular , SARS-CoV-2/immunology , Adult , Aged , Antigens, Viral/immunology , Biomarkers , Female , Humans , Immunophenotyping , Lymphocyte Count , Male , Middle Aged , T-Cell Antigen Receptor Specificity , T-Lymphocyte Subsets/immunology , T-Lymphocyte Subsets/metabolism , Young Adult
9.
Nat Commun ; 12(1): 4886, 2021 08 09.
Article in English | MEDLINE | ID: covidwho-1349666

ABSTRACT

Wide-scale SARS-CoV-2 genome sequencing is critical to tracking viral evolution during the ongoing pandemic. We develop the software tool, Variant Database (VDB), for quickly examining the changing landscape of spike mutations. Using VDB, we detect an emerging lineage of SARS-CoV-2 in the New York region that shares mutations with previously reported variants. The most common sets of spike mutations in this lineage (now designated as B.1.526) are L5F, T95I, D253G, E484K or S477N, D614G, and A701V. This lineage was first sequenced in late November 2020. Phylodynamic inference confirmed the rapid growth of the B.1.526 lineage. In concert with other variants, like B.1.1.7, the rise of B.1.526 appears to have extended the duration of the second wave of COVID-19 cases in NYC in early 2021. Pseudovirus neutralization experiments demonstrated that B.1.526 spike mutations adversely affect the neutralization titer of convalescent and vaccinee plasma, supporting the public health relevance of this lineage.


Subject(s)
COVID-19/virology , SARS-CoV-2/classification , SARS-CoV-2/isolation & purification , COVID-19/epidemiology , Genome, Viral , Humans , Models, Molecular , Mutation , New York/epidemiology , Phylogeny , SARS-CoV-2/genetics , Software , Spike Glycoprotein, Coronavirus/genetics
11.
Immunity ; 54(8): 1853-1868.e7, 2021 08 10.
Article in English | MEDLINE | ID: covidwho-1330891

ABSTRACT

Antibodies elicited by infection accumulate somatic mutations in germinal centers that can increase affinity for cognate antigens. We analyzed 6 independent groups of clonally related severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) Spike receptor-binding domain (RBD)-specific antibodies from 5 individuals shortly after infection and later in convalescence to determine the impact of maturation over months. In addition to increased affinity and neutralization potency, antibody evolution changed the mutational pathways for the acquisition of viral resistance and restricted neutralization escape options. For some antibodies, maturation imposed a requirement for multiple substitutions to enable escape. For certain antibodies, affinity maturation enabled the neutralization of circulating SARS-CoV-2 variants of concern and heterologous sarbecoviruses. Antibody-antigen structures revealed that these properties resulted from substitutions that allowed additional variability at the interface with the RBD. These findings suggest that increasing antibody diversity through prolonged or repeated antigen exposure may improve protection against diversifying SARS-CoV-2 populations, and perhaps against other pandemic threat coronaviruses.


Subject(s)
Antibody Affinity/immunology , COVID-19/immunology , COVID-19/virology , Host-Pathogen Interactions/immunology , Mutation , SARS-CoV-2/genetics , SARS-CoV-2/immunology , Antibodies, Neutralizing/chemistry , Antibodies, Neutralizing/immunology , Antibodies, Viral/chemistry , Antibodies, Viral/immunology , Antigens, Viral/chemistry , Antigens, Viral/genetics , Antigens, Viral/immunology , Epitopes/chemistry , Epitopes/immunology , Humans , Models, Molecular , Neutralization Tests , Protein Binding , Protein Conformation , SARS-CoV-2/pathogenicity , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/immunology , Structure-Activity Relationship , Virulence/genetics
12.
Cell Rep ; 36(4): 109450, 2021 07 27.
Article in English | MEDLINE | ID: covidwho-1306890

ABSTRACT

Improving clinical care for individuals infected with SARS-CoV-2 variants is a global health priority. Small-molecule antivirals like remdesivir (RDV) and biologics such as human monoclonal antibodies (mAbs) have demonstrated therapeutic efficacy against SARS-CoV-2, the causative agent of coronavirus disease 2019 (COVID-19). It is not known whether combination RDV/mAb will improve outcomes over single-agent therapies or whether antibody therapies will remain efficacious against variants. Here, we show that a combination of two mAbs in clinical trials, C144 and C135, have potent antiviral effects against even when initiated 48 h after infection and have therapeutic efficacy in vivo against the B.1.351 variant of concern (VOC). Combining RDV and antibodies provided a modest improvement in outcomes compared with single agents. These data support the continued use of RDV to treat SARS-CoV-2 infections and the continued clinical development of the C144 and C135 antibody combination to treat patients infected with SARS-CoV-2 variants.


Subject(s)
Antibodies, Monoclonal/pharmacology , COVID-19/drug therapy , SARS-CoV-2/drug effects , Animals , Antibodies, Monoclonal/immunology , Antiviral Agents/pharmacology , Humans , Mice , SARS-CoV-2/pathogenicity
13.
Nat Commun ; 12(1): 4196, 2021 07 07.
Article in English | MEDLINE | ID: covidwho-1301167

ABSTRACT

Monoclonal antibodies targeting a variety of epitopes have been isolated from individuals previously infected with SARS-CoV-2, but the relative contributions of these different antibody classes to the polyclonal response remains unclear. Here we use a yeast-display system to map all mutations to the viral spike receptor-binding domain (RBD) that escape binding by representatives of three potently neutralizing classes of anti-RBD antibodies with high-resolution structures. We compare the antibody-escape maps to similar maps for convalescent polyclonal plasmas, including plasmas from individuals from whom some of the antibodies were isolated. While the binding of polyclonal plasma antibodies are affected by mutations across multiple RBD epitopes, the plasma-escape maps most resemble those of a single class of antibodies that target an epitope on the RBD that includes site E484. Therefore, although the human immune system can produce antibodies that target diverse RBD epitopes, in practice the polyclonal response to infection is skewed towards a single class of antibodies targeting an epitope that is already undergoing rapid evolution.


Subject(s)
Antibodies, Viral/immunology , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/immunology , Antibodies, Monoclonal/immunology , Antibodies, Neutralizing/immunology , Binding Sites , COVID-19/immunology , Epitopes , HLA Antigens/immunology , Humans , Immune Evasion/genetics , Models, Molecular , Mutation , Neutralization Tests , Protein Domains , SARS-CoV-2/chemistry , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/chemistry
14.
PLoS Pathog ; 17(7): e1009688, 2021 07.
Article in English | MEDLINE | ID: covidwho-1298083

ABSTRACT

There is an urgent need for effective therapeutic interventions against SARS-CoV-2, including new variants that continue to arise. Neutralizing monoclonal antibodies have shown promise in clinical studies. We investigated the therapeutic efficacy of a combination of two potent monoclonal antibodies, C135-LS and C144-LS that carry half-life extension mutations, in the rhesus macaque model of COVID-19. Twelve young adult macaques (three groups of four animals) were inoculated intranasally and intra-tracheally with a high dose of SARS-CoV-2 and 24 hours later, treated intravenously with a high (40 mg/kg) or low (12 mg/kg) dose of the C135-LS and C144-LS antibody combination, or a control monoclonal antibody. Animals were monitored for 7 days. Compared to the control animals, animals treated with either dose of the anti-SARS-CoV-2 antibodies showed similarly improved clinical scores, lower levels of virus replication in upper and lower respiratory tract, and significantly reduced interstitial pneumonia, as measured by comprehensive lung histology. In conclusion, this study provides proof-of-concept in support of further clinical development of these monoclonal antibodies against COVID-19 during early infection.


Subject(s)
Antibodies, Neutralizing/therapeutic use , Antibodies, Viral/therapeutic use , COVID-19/therapy , Lung/pathology , SARS-CoV-2/immunology , Virus Replication , Animals , Antibodies, Monoclonal/blood , Antibodies, Monoclonal/immunology , Antibodies, Monoclonal/therapeutic use , Antibodies, Neutralizing/blood , Antibodies, Neutralizing/immunology , Antibodies, Viral/blood , Antibodies, Viral/immunology , COVID-19/pathology , COVID-19/virology , Disease Models, Animal , Female , Lung/diagnostic imaging , Macaca mulatta , Male , Multivariate Analysis , Radiography , Respiratory System/virology , SARS-CoV-2/physiology , Time Factors , Treatment Outcome , Virus Replication/immunology
15.
Nature ; 595(7867): 426-431, 2021 07.
Article in English | MEDLINE | ID: covidwho-1267998

ABSTRACT

More than one year after its inception, the coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remains difficult to control despite the availability of several working vaccines. Progress in controlling the pandemic is slowed by the emergence of variants that appear to be more transmissible and more resistant to antibodies1,2. Here we report on a cohort of 63 individuals who have recovered from COVID-19 assessed at 1.3, 6.2 and 12 months after SARS-CoV-2 infection, 41% of whom also received mRNA vaccines3,4. In the absence of vaccination, antibody reactivity to the receptor binding domain (RBD) of SARS-CoV-2, neutralizing activity and the number of RBD-specific memory B cells remain relatively stable between 6 and 12 months after infection. Vaccination increases all components of the humoral response and, as expected, results in serum neutralizing activities against variants of concern similar to or greater than the neutralizing activity against the original Wuhan Hu-1 strain achieved by vaccination of naive individuals2,5-8. The mechanism underlying these broad-based responses involves ongoing antibody somatic mutation, memory B cell clonal turnover and development of monoclonal antibodies that are exceptionally resistant to SARS-CoV-2 RBD mutations, including those found in the variants of concern4,9. In addition, B cell clones expressing broad and potent antibodies are selectively retained in the repertoire over time and expand markedly after vaccination. The data suggest that immunity in convalescent individuals will be very long lasting and that convalescent individuals who receive available mRNA vaccines will produce antibodies and memory B cells that should be protective against circulating SARS-CoV-2 variants.


Subject(s)
Antibodies, Neutralizing/blood , Antibodies, Neutralizing/immunology , Antibodies, Viral/blood , Antibodies, Viral/immunology , COVID-19/blood , COVID-19/immunology , SARS-CoV-2/immunology , Adult , Aged , Antibodies, Monoclonal/immunology , B-Lymphocytes/immunology , Enzyme-Linked Immunosorbent Assay , Epitopes/immunology , Female , Humans , Immunologic Memory/immunology , Male , Middle Aged , SARS-CoV-2/chemistry , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/immunology , Time Factors
16.
Nature ; 595(7866): 278-282, 2021 07.
Article in English | MEDLINE | ID: covidwho-1258586

ABSTRACT

Since the start of the COVID-19 pandemic, SARS-CoV-2 has caused millions of deaths worldwide. Although a number of vaccines have been deployed, the continual evolution of the receptor-binding domain (RBD) of the virus has challenged their efficacy. In particular, the emerging variants B.1.1.7, B.1.351 and P.1 (first detected in the UK, South Africa and Brazil, respectively) have compromised the efficacy of sera from patients who have recovered from COVID-19 and immunotherapies that have received emergency use authorization1-3. One potential alternative to avert viral escape is the use of camelid VHHs (variable heavy chain domains of heavy chain antibody (also known as nanobodies)), which can recognize epitopes that are often inaccessible to conventional antibodies4. Here, we isolate anti-RBD nanobodies from llamas and from mice that we engineered to produce VHHs cloned from alpacas, dromedaries and Bactrian camels. We identified two groups of highly neutralizing nanobodies. Group 1 circumvents antigenic drift by recognizing an RBD region that is highly conserved in coronaviruses but rarely targeted by human antibodies. Group 2 is almost exclusively focused to the RBD-ACE2 interface and does not neutralize SARS-CoV-2 variants that carry E484K or N501Y substitutions. However, nanobodies in group 2 retain full neutralization activity against these variants when expressed as homotrimers, and-to our knowledge-rival the most potent antibodies against SARS-CoV-2 that have been produced to date. These findings suggest that multivalent nanobodies overcome SARS-CoV-2 mutations through two separate mechanisms: enhanced avidity for the ACE2-binding domain and recognition of conserved epitopes that are largely inaccessible to human antibodies. Therefore, although new SARS-CoV-2 mutants will continue to emerge, nanobodies represent promising tools to prevent COVID-19 mortality when vaccines are compromised.


Subject(s)
Antibodies, Neutralizing/immunology , Camelids, New World/immunology , SARS-CoV-2/immunology , Single-Domain Antibodies/chemistry , Single-Domain Antibodies/immunology , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/immunology , Animals , Antibodies, Neutralizing/chemistry , Antibodies, Neutralizing/genetics , Antibodies, Neutralizing/isolation & purification , CRISPR-Cas Systems , Camelids, New World/genetics , Female , Gene Editing , Humans , Male , Mice , Mice, Inbred C57BL , Models, Molecular , Mutation , Neutralization Tests , SARS-CoV-2/chemistry , SARS-CoV-2/genetics , Single-Domain Antibodies/genetics , Single-Domain Antibodies/isolation & purification , Somatic Hypermutation, Immunoglobulin/genetics
17.
Clin Chem ; 67(9): 1249-1258, 2021 09 01.
Article in English | MEDLINE | ID: covidwho-1207270

ABSTRACT

BACKGROUND: Low initial severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody titers dropping to undetectable levels within months after infection have raised concerns about long-term immunity. Both the antibody levels and the avidity of the antibody-antigen interaction should be examined to understand the quality of the antibody response. METHODS: A testing-on-a-probe "plus" panel (TOP-Plus) was developed to include a newly developed avidity assay built into the previously described SARS-CoV-2 TOP assays that measured total antibody (TAb), surrogate neutralizing antibody (SNAb), IgM, and IgG on a versatile biosensor platform. TAb and SNAb levels were compared with avidity in previously infected individuals at 1.3 and 6.2 months after infection in paired samples from 80 patients with coronavirus disease 2019 (COVID-19). Sera from individuals vaccinated for SARS-CoV-2 were also evaluated for antibody avidity. RESULTS: The newly designed avidity assay in this TOP panel correlated well with a reference Bio-Layer Interferometry avidity assay (r = 0.88). The imprecision of the TOP avidity assay was <10%. Although TAb and neutralization activity (by SNAb) decreased between 1.3 and 6.2 months after infection, the antibody avidity increased significantly (P < 0.0001). Antibody avidity in 10 SARS-CoV-2 vaccinated individuals (median: 28 days after vaccination) was comparable to the measured antibody avidity in infected individuals (median: 26 days after infection). CONCLUSIONS: This highly precise and versatile TOP-Plus panel with the ability to measure SARS-CoV-2 TAb, SNAb, IgG, and IgM antibody levels and avidity of individual sera on one sensor can become a valuable asset in monitoring not only patients infected with SARS-CoV-2 but also the status of individuals' COVID-19 vaccination response.


Subject(s)
Antibodies, Viral/blood , Antibody Affinity/physiology , Biosensing Techniques/methods , COVID-19/immunology , SARS-CoV-2/immunology , Adolescent , Adult , Aged , Antibodies, Neutralizing/blood , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , COVID-19/pathology , COVID-19/virology , COVID-19 Vaccines/administration & dosage , Female , Humans , Immunoglobulin G/blood , Immunoglobulin M/blood , Interferometry , Male , Middle Aged , SARS-CoV-2/isolation & purification , Time Factors , Young Adult
18.
N Engl J Med ; 384(23): 2212-2218, 2021 06 10.
Article in English | MEDLINE | ID: covidwho-1196905

ABSTRACT

Emerging variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are of clinical concern. In a cohort of 417 persons who had received the second dose of BNT162b2 (Pfizer-BioNTech) or mRNA-1273 (Moderna) vaccine at least 2 weeks previously, we identified 2 women with vaccine breakthrough infection. Despite evidence of vaccine efficacy in both women, symptoms of coronavirus disease 2019 developed, and they tested positive for SARS-CoV-2 by polymerase-chain-reaction testing. Viral sequencing revealed variants of likely clinical importance, including E484K in 1 woman and three mutations (T95I, del142-144, and D614G) in both. These observations indicate a potential risk of illness after successful vaccination and subsequent infection with variant virus, and they provide support for continued efforts to prevent and diagnose infection and to characterize variants in vaccinated persons. (Funded by the National Institutes of Health and others.).


Subject(s)
Antibodies, Neutralizing/blood , COVID-19 Vaccines , COVID-19/virology , Mutation , SARS-CoV-2/genetics , Aged , Antibodies, Viral/blood , COVID-19/diagnosis , Female , Humans , Middle Aged , Neutralization Tests , Phylogeny , Polymerase Chain Reaction , SARS-CoV-2/immunology , SARS-CoV-2/isolation & purification , Sequence Analysis, RNA , Spike Glycoprotein, Coronavirus/genetics , Viral Load
19.
Nature ; 593(7859): 424-428, 2021 05.
Article in English | MEDLINE | ID: covidwho-1152859

ABSTRACT

Neutralizing antibodies that target the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein are among the most promising approaches against COVID-191,2. A bispecific IgG1-like molecule (CoV-X2) has been developed on the basis of C121 and C135, two antibodies derived from donors who had recovered from COVID-193. Here we show that CoV-X2 simultaneously binds two independent sites on the RBD and, unlike its parental antibodies, prevents detectable spike binding to the cellular receptor of the virus, angiotensin-converting enzyme 2 (ACE2). Furthermore, CoV-X2 neutralizes wild-type SARS-CoV-2 and its variants of concern, as well as escape mutants generated by the parental monoclonal antibodies. We also found that in a mouse model of SARS-CoV-2 infection with lung inflammation, CoV-X2 protects mice from disease and suppresses viral escape. Thus, the simultaneous targeting of non-overlapping RBD epitopes by IgG-like bispecific antibodies is feasible and effective, and combines the advantages of antibody cocktails with those of single-molecule approaches.


Subject(s)
Antibodies, Bispecific/immunology , Antibodies, Neutralizing/immunology , COVID-19/immunology , COVID-19/virology , Immunoglobulin G/immunology , SARS-CoV-2/immunology , Angiotensin-Converting Enzyme 2/antagonists & inhibitors , Angiotensin-Converting Enzyme 2/genetics , Angiotensin-Converting Enzyme 2/metabolism , Animals , Antibodies, Bispecific/therapeutic use , Antibodies, Monoclonal/immunology , Antibodies, Neutralizing/therapeutic use , Body Weight , COVID-19/drug therapy , COVID-19/prevention & control , Dependovirus/genetics , Disease Models, Animal , Epitopes, B-Lymphocyte/chemistry , Epitopes, B-Lymphocyte/immunology , Female , Humans , Immune Evasion/genetics , Mice , Mice, Inbred C57BL , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/antagonists & inhibitors , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/immunology
20.
Nature ; 592(7855): 616-622, 2021 04.
Article in English | MEDLINE | ID: covidwho-1075232

ABSTRACT

Here we report on the antibody and memory B cell responses of a cohort of 20 volunteers who received the Moderna (mRNA-1273) or Pfizer-BioNTech (BNT162b2) vaccine against SARS-CoV-21-4. Eight weeks after the second injection of vaccine, volunteers showed high levels of IgM and IgG anti-SARS-CoV-2 spike protein (S) and receptor-binding-domain (RBD) binding titre. Moreover, the plasma neutralizing activity and relative numbers of RBD-specific memory B cells of vaccinated volunteers were equivalent to those of individuals who had recovered from natural infection5,6. However, activity against SARS-CoV-2 variants that encode E484K-, N501Y- or K417N/E484K/N501-mutant S was reduced by a small-but significant-margin. The monoclonal antibodies elicited by the vaccines potently neutralize SARS-CoV-2, and target a number of different RBD epitopes in common with monoclonal antibodies isolated from infected donors5-8. However, neutralization by 14 of the 17 most-potent monoclonal antibodies that we tested was reduced or abolished by the K417N, E484K or N501Y mutation. Notably, these mutations were selected when we cultured recombinant vesicular stomatitis virus expressing SARS-CoV-2 S in the presence of the monoclonal antibodies elicited by the vaccines. Together, these results suggest that the monoclonal antibodies in clinical use should be tested against newly arising variants, and that mRNA vaccines may need to be updated periodically to avoid a potential loss of clinical efficacy.


Subject(s)
Antibodies, Viral/blood , COVID-19 Vaccines/immunology , COVID-19/immunology , COVID-19/virology , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/genetics , Vaccines, Synthetic/immunology , Adult , Aged , Antibodies, Monoclonal/blood , Antibodies, Monoclonal/immunology , Antibodies, Neutralizing/blood , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , B-Lymphocytes/immunology , COVID-19 Vaccines/genetics , Cryoelectron Microscopy , Epitopes, B-Lymphocyte/chemistry , Epitopes, B-Lymphocyte/immunology , Epitopes, B-Lymphocyte/ultrastructure , Female , Humans , Immunization, Secondary , Immunoglobulin G/blood , Immunoglobulin G/immunology , Immunoglobulin M/blood , Immunoglobulin M/immunology , Immunologic Memory/immunology , Male , Middle Aged , Models, Molecular , Mutation , Neutralization Tests , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/immunology , Vaccines, Synthetic/genetics
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