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1.
Cell Rep Med ; 3(11): 100811, 2022 Nov 15.
Article in English | MEDLINE | ID: covidwho-2150820

ABSTRACT

Coronavirus disease 2019 (COVID-19) convalescent plasma (CCP), a passive polyclonal antibody therapeutic agent, has had mixed clinical results. Although antibody neutralization is the predominant approach to benchmarking CCP efficacy, CCP may also influence the evolution of the endogenous antibody response. Using systems serology to comprehensively profile severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) functional antibodies of hospitalized people with COVID-19 enrolled in a randomized controlled trial of CCP (ClinicalTrials.gov: NCT04397757), we find that the clinical benefits of CCP are associated with a shift toward reduced inflammatory Spike (S) responses and enhanced nucleocapsid (N) humoral responses. We find that CCP has the greatest clinical benefit in participants with low pre-existing anti-SARS-CoV-2 antibody function and that CCP-induced immunomodulatory Fc glycan profiles and N immunodominant profiles persist for at least 2 months. We highlight a potential mechanism of action of CCP associated with durable immunomodulation, outline optimal patient characteristics for CCP treatment, and provide guidance for development of a different class of COVID-19 hyperinflammation-targeting antibody therapeutic agents.


Subject(s)
COVID-19 , Humans , COVID-19/therapy , SARS-CoV-2 , Immunization, Passive/methods , Antibodies, Viral/therapeutic use , Nucleocapsid
2.
PLoS One ; 17(6): e0267796, 2022.
Article in English | MEDLINE | ID: covidwho-2140390

ABSTRACT

The current global COVID-19 pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has resulted in a public health crisis with more than 168 million cases reported globally and more than 4.5 million deaths at the time of writing. In addition to the direct impact of the disease, the economic impact has been significant as public health measures to contain or reduce the spread have led to country wide lockdowns resulting in near closure of many sectors of the economy. Antibodies are a principal determinant of the humoral immune response to COVID-19 infections and may have the potential to reduce disease and spread of the virus. The development of monoclonal antibodies (mAbs) represents a therapeutic option that can be produced at large quantity and high quality. In the present study, a mAb combination mixture therapy was investigated for its capability to specifically neutralize SARS-CoV-2. We demonstrate that each of the antibodies bind the spike protein and neutralize the virus, preventing it from infecting cells in an in vitro cell-based assay, including multiple viral variants that are currently circulating in the human population. In addition, we investigated the effects of two different mutations in the Fc portion (YTE and LALA) of the antibody on Fc effector function and the ability to alleviate potential antibody-dependent enhancement of disease. These data demonstrate the potential of a combination of two mAbs that target two different epitopes on the SARS-CoV2 spike protein to provide protection against SARS-CoV-2 infection in humans while extending serum half-life and preventing antibody-dependent enhancement of disease.


Subject(s)
COVID-19 , SARS-CoV-2 , Antibodies, Monoclonal/therapeutic use , Antibodies, Neutralizing , Antibodies, Viral/therapeutic use , COVID-19/drug therapy , Communicable Disease Control , Humans , Pandemics , RNA, Viral , Spike Glycoprotein, Coronavirus
3.
J Biomed Sci ; 29(1): 37, 2022 Jun 09.
Article in English | MEDLINE | ID: covidwho-2139298

ABSTRACT

BACKGROUND: Calls for the coronavirus to be treated as an endemic illness, such as the flu, are increasing. After achieving high coverage of COVID-19 vaccination, therapeutic drugs have become important for future SARS-CoV-2 variant outbreaks. Although many monoclonal antibodies have been approved for emergency use as treatments for SARS-CoV-2 infection, some monoclonal antibodies are not authorized for variant treatment. Broad-spectrum monoclonal antibodies are unmet medical needs. METHODS: We used a DNA prime-protein boost approach to generate high-quality monoclonal antibodies. A standard ELISA was employed for the primary screen, and spike protein-human angiotensin-converting enzyme 2 blocking assays were used for the secondary screen. The top 5 blocking clones were selected for further characterization, including binding ability, neutralization potency, and epitope mapping. The therapeutic effects of the best monoclonal antibody against SARS-CoV-2 infection were evaluated in a hamster infection model. RESULTS: Several monoclonal antibodies were selected that neutralize different SARS-CoV-2 variants of concern (VOCs). These VOCs include Alpha, Beta, Gamma, Delta, Kappa and Lambda variants. The high neutralizing antibody titers against the Beta variant would be important to treat Beta-like variants. Among these monoclonal antibodies, mAb-S5 displays the best potency in terms of binding affinity and neutralizing capacity. Importantly, mAb-S5 protects animals from SARS-CoV-2 challenge, including the Wuhan strain, D614G, Alpha and Delta variants, although mAb-S5 exhibits decreased neutralization potency against the Delta variant. Furthermore, the identified neutralizing epitopes of monoclonal antibodies are all located in the receptor-binding domain (RBD) of the spike protein but in different regions. CONCLUSIONS: Our approach generates high-potency monoclonal antibodies against a broad spectrum of VOCs. Multiple monoclonal antibody combinations may be the best strategy to treat future SARS-CoV-2 variant outbreaks.


Subject(s)
Antibodies, Monoclonal , COVID-19 , SARS-CoV-2 , Animals , Antibodies, Monoclonal/therapeutic use , Antibodies, Neutralizing/therapeutic use , Antibodies, Viral/therapeutic use , COVID-19/drug therapy , COVID-19 Vaccines , Cricetinae , Humans , Spike Glycoprotein, Coronavirus/genetics
4.
Clin Immunol ; 245: 109144, 2022 Dec.
Article in English | MEDLINE | ID: covidwho-2122391

ABSTRACT

Rituximab (RTX) is a very effective treatment for autoimmune rheumatic diseases (AIRD), but it increases infection risk and impairs vaccine responses. Herein we evaluated the antibody response of RTX-treated patients to the supplemental COVID-19 vaccine. After the supplemental dose, 53.1% of patients had detectable antibody titers. Only 36% of patients who did not mount an antibody response after the original vaccine series did have detectable antibodies after the supplemental dose (seroconversion). Patients with undetectable CD20+ cell levels did not seroconvert while hypogammaglobulinemia was associated with a 15-times decrease in the likelihood of seroconversion. Although we noted 11 COVID-19 infections after the supplemental dose, no patients who received monoclonal antibodies pre-exposure prophylaxis had COVID-19 afterwards. We propose that patients receiving RTX should continue to be prioritized for prophylaxis measures and that vaccination should be timed after B cell recovery wherever possible.


Subject(s)
Autoimmune Diseases , COVID-19 , Humans , Rituximab/therapeutic use , Seroconversion , COVID-19 Vaccines , COVID-19/drug therapy , COVID-19/prevention & control , SARS-CoV-2 , Vaccination , Antibodies, Viral/therapeutic use
5.
Virol J ; 19(1): 186, 2022 11 13.
Article in English | MEDLINE | ID: covidwho-2117998

ABSTRACT

BACKGROUND: The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is the cause of coronavirus disease 2019 (COVID-19), which is currently a worldwide pandemic. There are limited available treatments for severe COVID-19 patients. However, some evidence suggests that intravenous immunoglobulin (IVIg) provides clinical benefits for these patients. METHODS: We administered IVIg to 23 severe COVID-19 patients, and all of them survived. Four related coronaviruses can cause the common cold. We speculated that cross-reactivity of SARS-CoV-2 and other common coronaviruses might partially explain the clinical efficacy of IVIg therapy. Thus, we performed multiple alignment analysis of the spike (S), membrane (M), and nucleotide (N) proteins from SARS-CoV-2 and the common coronaviruses to identify conserved regions. Next, we synthesized 25 peptides that were conserved regions and tested their IVIg seropositivity. RESULTS: The results indicated four peptides had significant or nearly significant seropositivity, and all of them were associated with the S and M proteins. Examination of the immune responses of healthy volunteers to each synthetic peptide indicated high seropositivity to the two peptides from S protein. Blood samples from healthy individuals may have pre-existing anti-SARS-CoV-2 IgGs, and IVIg is a potentially effective therapy for severe COVID-19. CONCLUSION: In conclusion, blood samples from many healthy individuals have pre-existing anti-SARS-CoV-2 IgGs, and IVIg may be an effective therapy for severe COVID-19.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , COVID-19/drug therapy , Spike Glycoprotein, Coronavirus , Immunoglobulins, Intravenous/therapeutic use , Antibodies, Viral/therapeutic use , Immunoglobulin G
6.
Rev Esp Quimioter ; 35 Suppl 3: 16-19, 2022 Oct.
Article in English | MEDLINE | ID: covidwho-2091723

ABSTRACT

The COVID-19 pandemic has boosted significant research in developing monoclonal antibodies (mAbs) to treat and prevent SARS-CoV-2 infection. Clinical trials have shown that mAbs are safe and effective in preventing hospitalization and death in patients with mild to moderate COVID-19 risk factors for progression. mAbs have also been effective for treating severe disease in seronegative patients and preventing COVID-19. So far, studies have been carried out in a largely unvaccinated population at a time when the omicron variant was not described. Future research should address these limitations and provide information on specific population groups, including immunosuppressed and previously infected individuals.


Subject(s)
Antibodies, Neutralizing , COVID-19 , Humans , Antibodies, Neutralizing/therapeutic use , Neutralization Tests , SARS-CoV-2 , Antibodies, Viral/therapeutic use , Pandemics , Spike Glycoprotein, Coronavirus , Viral Envelope Proteins , Membrane Glycoproteins , Antibodies, Monoclonal/therapeutic use
7.
Viruses ; 14(11)2022 Oct 27.
Article in English | MEDLINE | ID: covidwho-2090364

ABSTRACT

Historically the therapeutic potential of polyclonal passive immunotherapies in viral diseases has been related to antiviral neutralizing antibodies, but there is also considerable evidence that non-neutralizing antibodies can translate into clinical benefit as well. In the setting of SARS-CoV-2 infection, we review here in vitro and in vivo evidence supporting a contributing role for anti-nucleocapsid antibodies. Retrospective investigation of anti-nucleocapsid antibody levels in randomized clinical trials of COVID-19 convalescent plasma is warranted to better understand whether there is an association with efficacy or lack thereof.


Subject(s)
COVID-19 , Humans , COVID-19/therapy , SARS-CoV-2 , Antibodies, Viral/therapeutic use , Retrospective Studies , Antibodies, Neutralizing/therapeutic use , Immunization, Passive
8.
Sci Rep ; 12(1): 17955, 2022 Oct 26.
Article in English | MEDLINE | ID: covidwho-2087312

ABSTRACT

Progress has been made in COVID-19 vaccine development, with encouraging safety and efficacy data. The purpose of this study was to investigate the immunogenicity of inactivated COVID-19 vaccine in patients with autoimmune inflammatory rheumatic diseases (AIIRD). Patients with AIIRD (n = 101) were included in this study. All patients received 2 doses of inactivated COVID-19 vaccine. Serum anti-S1/RBD protein IgG was detected 2-16 weeks after the second vaccination. Seropositivity was defined as IgG ≥ 1.00 bound antibody unit S/CO. Immunogenicity of inactivated COVID-19 vaccine was assessed by seropositivity rate and the levels of serum IgG antibody against anti-S1/RBD protein, compared with the general population (n = 46). There was no difference by statistical significance in the seropositivity rate between patients with AIIRD (82.2%) and SLE (86.1%) and the control group (93.5%), p > 0.05. The level of anti-S1/RBD protein IgG antibodies in patients with AIIRD (median [IQR], 8.8 [2.2-17.3]) and SLE (median [IQR], 9.6 [2.4-20.4]) was comparable to that in the control group (median [IQR], 7.2 [3.1-14.2]), p > 0.05. Patients treated with glucocorticoids(GCs) (median dose, [IQR]: 2.5 mg/day [IQR 2.5-5.0]) or hydroxychloroquine(HCQ) or GCs + HCQ without other immunomodulatory medications, had an appropriate immunogenic response(88.1%) with high levels of anti-S1/RBD protein IgG(median [IQR], 12.1 [6.5-20.4]). Neither of patients treated with rituximab had positive serum antibodies, which was statistically significant, compared with the control group (p < 0.01). Compared with the control group, methotrexate(MTX) and iguratimod(IGU) was significantly reduced the level of anti-S1/RBD protein IgG antibodies. Inactivated COVID-19 vaccine had appropriate immunogenicity in patients with AIIRD. Immunogenicity of inactivated COVID-19 vaccine was severely impaired by rituximab, and also suppressed by MTX and IGU, while low doses of GC and HCQ had negligible effect.


Subject(s)
Autoimmune Diseases , COVID-19 , Lupus Erythematosus, Systemic , Rheumatic Diseases , Rheumatic Fever , Humans , COVID-19 Vaccines , Rheumatic Diseases/drug therapy , Rheumatic Diseases/epidemiology , Hydroxychloroquine/therapeutic use , Methotrexate/therapeutic use , Rituximab/therapeutic use , Autoimmune Diseases/epidemiology , COVID-19/prevention & control , Immunoglobulin G/therapeutic use , Antibodies, Viral/therapeutic use , Immunogenicity, Vaccine
9.
Med (N Y) ; 3(10): 705-721.e11, 2022 10 14.
Article in English | MEDLINE | ID: covidwho-2076532

ABSTRACT

BACKGROUND: The continual emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants of concern, in particular the newly emerged Omicron (B.1.1.529) variant and its BA.X lineages, has rendered ineffective a number of previously FDA emergency use authorized SARS-CoV-2 neutralizing antibody therapies. Furthermore, those approved antibodies with neutralizing activity against Omicron BA.1 are reportedly ineffective against the subset of Omicron subvariants that contain a R346K substitution, BA.1.1, and the more recently emergent BA.2, demonstrating the continued need for discovery and characterization of candidate therapeutic antibodies with the breadth and potency of neutralizing activity required to treat newly diagnosed COVID-19 linked to recently emerged variants of concern. METHODS: Following a campaign of antibody discovery based on the vaccination of Harbor H2L2 mice with defined SARS-CoV-2 spike domains, we have characterized the activity of a large collection of spike-binding antibodies and identified a lead neutralizing human IgG1 LALA antibody, STI-9167. FINDINGS: STI-9167 has potent, broad-spectrum neutralizing activity against the current SARS-COV-2 variants of concern and retained activity against each of the tested Omicron subvariants in both pseudotype and live virus neutralization assays. Furthermore, STI-9167 nAb administered intranasally or intravenously provided protection against weight loss and reduced virus lung titers to levels below the limit of quantitation in Omicron-infected K18-hACE2 transgenic mice. CONCLUSIONS: With this established activity profile, a cGMP cell line has been developed and used to produce cGMP drug product intended for intravenous or intranasal use in human clinical trials. FUNDING: Funded by CRIPT (no. 75N93021R00014), DARPA (HR0011-19-2-0020), and NCI Seronet (U54CA260560).


Subject(s)
Antibodies, Neutralizing , COVID-19 , Administration, Intranasal , Animals , Antibodies, Neutralizing/therapeutic use , Antibodies, Viral/therapeutic use , COVID-19/drug therapy , Humans , Immunoglobulin G , Membrane Glycoproteins , Mice , Neutralization Tests , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/genetics , Viral Envelope Proteins
10.
Cell Rep ; 41(5): 111528, 2022 Nov 01.
Article in English | MEDLINE | ID: covidwho-2060517

ABSTRACT

The emergence and global spread of the SARS-CoV-2 Omicron variants, which carry an unprecedented number of mutations, raise serious concerns due to the reduced efficacy of current vaccines and resistance to therapeutic antibodies. Here, we report the generation and characterization of two potent human monoclonal antibodies, NA8 and NE12, against the receptor-binding domain of the SARS-CoV-2 spike protein. NA8 interacts with a highly conserved region and has a breadth of neutralization with picomolar potency against the Beta variant and the Omicron BA.1 and BA.2 sublineages and nanomolar potency against BA.2.12.1 and BA.4. Combination of NA8 and NE12 retains potent neutralizing activity against the major SARS-CoV-2 variants of concern. Cryo-EM analysis provides the structural basis for the broad and complementary neutralizing activity of these two antibodies. We confirm the in vivo protective and therapeutic efficacies of NA8 and NE12 in the hamster model. These results show that broad and potent human antibodies can overcome the continuous immune escape of evolving SARS-CoV-2 variants.


Subject(s)
Antineoplastic Agents, Immunological , COVID-19 , Humans , SARS-CoV-2 , Antibodies, Monoclonal/pharmacology , Antibodies, Monoclonal/therapeutic use , Antibodies, Monoclonal/genetics , Neutralization Tests , Antibodies, Viral/therapeutic use , Viral Envelope Proteins , Membrane Glycoproteins/genetics , Antibodies, Neutralizing/therapeutic use
11.
Nat Commun ; 13(1): 5814, 2022 10 03.
Article in English | MEDLINE | ID: covidwho-2050372

ABSTRACT

Monoclonal antibodies are a promising approach to treat COVID-19, however the emergence of SARS-CoV-2 variants has challenged the efficacy and future of these therapies. Antibody cocktails are being employed to mitigate these challenges, but neutralization escape remains a major challenge and alternative strategies are needed. Here we present two anti-SARS-CoV-2 spike binding antibodies, one Class 1 and one Class 4, selected from our non-immune human single-chain variable fragment (scFv) phage library, that are engineered into four, fully-human IgG-like bispecific antibodies (BsAb). Prophylaxis of hACE2 mice and post-infection treatment of golden hamsters demonstrates the efficacy of the monospecific antibodies against the original Wuhan strain, while promising in vitro results with the BsAbs demonstrate enhanced binding and distinct synergistic effects on neutralizing activity against circulating variants of concern. In particular, one BsAb engineered in a tandem scFv-Fc configuration shows synergistic neutralization activity against several variants of concern including B.1.617.2. This work provides evidence that synergistic neutralization can be achieved using a BsAb scaffold, and serves as a foundation for the future development of broadly reactive BsAbs against emerging variants of concern.


Subject(s)
Antibodies, Bispecific , COVID-19 , Single-Chain Antibodies , Animals , Antibodies, Bispecific/genetics , Antibodies, Monoclonal , Antibodies, Neutralizing , Antibodies, Viral/therapeutic use , Cricetinae , Humans , Immunoglobulin G/genetics , Mice , Neutralization Tests , SARS-CoV-2/genetics , Single-Chain Antibodies/genetics , Spike Glycoprotein, Coronavirus/genetics
12.
BMC Infect Dis ; 22(1): 734, 2022 Sep 14.
Article in English | MEDLINE | ID: covidwho-2029696

ABSTRACT

BACKGROUND: Effective SARS-CoV-2 vaccination in patients receiving treatment with B-cell depleting agents is challenging. Information on vaccination responses in these patients are a valuable tool to develop efficient vaccination regimens. METHODS: In this single-center retrospective observational study, we report the humoral and cellular response in 34 patients receiving anti-CD20 antibody treatment for renal immune disease. RESULTS: After base immunization with SARS-CoV-2-vaccines, 92.0% developed a cellular, 32.4% a humoral response. Humoral immunity correlated with B-cell counts and the timespan between anti-CD20 antibody treatment and vaccination. All patients with > 21/µl B-cells, or > 197 days after treatment showed humoral response. CONCLUSIONS: Adequate timing of SARS-CoV-2-vaccinations after anti-CD20 antibody treatment and CD19 measurements are crucial to generate immunity. Awaiting partial B-cell recovery by postponing regularly scheduled anti-CD20 treatment should be considered in patients with stable immune disease. TRIAL REGISTRATION: This study has been retrospectively registered in the German Clinical Trials Register (DRKS00027049) on 29/10/2021.


Subject(s)
Autoimmune Diseases , COVID-19 , Viral Vaccines , Antibodies, Viral/therapeutic use , COVID-19 Vaccines , Humans , SARS-CoV-2
13.
Sci Rep ; 12(1): 15517, 2022 09 15.
Article in English | MEDLINE | ID: covidwho-2028729

ABSTRACT

Coronavirus disease 2019 (COVID-19) continues to significantly impact the global population, thus countermeasure platforms that enable rapid development of therapeutics against variants of SARS-CoV-2 are essential. We report use of a phage display human antibody library approach to rapidly identify neutralizing antibodies (nAbs) against SARS-CoV-2. We demonstrate the binding and neutralization capability of two nAbs, STI-2020 and STI-5041, against the SARS-CoV-2 WA-1 strain as well as the Alpha and Beta variants. STI-2020 and STI-5041 were protective when administered intravenously or intranasally in the golden (Syrian) hamster model of COVID-19 challenged with the WA-1 strain or Beta variant. The ability to administer nAbs intravenously and intranasally may have important therapeutic implications and Phase 1 healthy subjects clinical trials are ongoing.


Subject(s)
COVID-19 , Animals , Antibodies, Monoclonal , Antibodies, Neutralizing/therapeutic use , Antibodies, Viral/therapeutic use , Cricetinae , Humans , Mesocricetus , Neutralization Tests , SARS-CoV-2
14.
Sci Rep ; 12(1): 14772, 2022 08 30.
Article in English | MEDLINE | ID: covidwho-2016839

ABSTRACT

Limited data exists on SARS-CoV-2 sustained-response to vaccine in patients with rheumatic diseases. This study aims to evaluate neutralizing antibodies (nAB) induced by SARS-CoV-2 vaccine after 3 to 6 months from administration in Systemic Lupus Erythematosus (SLE) patients, as a surrogate of sustained-immunological response. This cross-sectional study compared nAB titre of 39 SLE patients and 37 Healthy individuals with no previous SARS-CoV-2 infection, who had all received a complete regimen of a mRNA SARS-CoV-2 vaccine within the last 3 to 6 months. We included four lines of SLE treatment including Not-treated, Hydroxychloroquine, immunosuppressive drugs and biological therapy. Glucocorticoids were allowed in all groups. Healthy and Not-treated individuals showed the highest levels of nAB. Treated patients presented lower nAB titres compared to Healthy: a 73% decrease for First-Line patients, 56% for Second-Line treatment and 72% for Third-Line. A multivariate analysis pointed to Glucocorticoids as the most associated factor with declining nAB levels (75% decrease) in treated SLE. Furthermore, a significant reduction in nAB titres was observed for Rituximab-users compared to Healthy subjects (89% decrease). Medium-term response of SLE patients to SARS-CoV-2 mRNA vaccines is negatively impacted in Glucocorticoids and Rituximab users. These findings might help to inform recommendations in vaccination protocols for SLE patients.


Subject(s)
COVID-19 , Lupus Erythematosus, Systemic , Antibodies, Neutralizing/therapeutic use , Antibodies, Viral/therapeutic use , COVID-19/prevention & control , COVID-19 Vaccines , Cross-Sectional Studies , Glucocorticoids/therapeutic use , Humans , Rituximab/therapeutic use , SARS-CoV-2 , Vaccines, Synthetic , mRNA Vaccines
15.
Int J Mol Sci ; 23(17)2022 Aug 28.
Article in English | MEDLINE | ID: covidwho-2006044

ABSTRACT

Since the first COVID-19 reports back in December of 2019, this viral infection caused by SARS-CoV-2 has claimed millions of lives. To control the COVID-19 pandemic, the Food and Drug Administration (FDA) and/or European Agency of Medicines (EMA) have granted Emergency Use Authorization (EUA) to nine therapeutic antibodies. Nonetheless, the natural evolution of SARS-CoV-2 has generated numerous variants of concern (VOCs) that have challenged the efficacy of the EUA antibodies. Here, we review the most relevant characteristics of these therapeutic antibodies, including timeline of approval, neutralization profile against the VOCs, selection methods of their variable regions, somatic mutations, HCDR3 and LCDR3 features, isotype, Fc modifications used in the therapeutic format, and epitope recognized on the receptor-binding domain (RBD) of SARS-CoV-2. One of the conclusions of the review is that the EUA therapeutic antibodies that still retain efficacy against new VOCs bind an epitope formed by conserved residues that seem to be evolutionarily conserved as thus, critical for the RBD:hACE-2 interaction. The information reviewed here should help to design new and more efficacious antibodies to prevent and/or treat COVID-19, as well as other infectious diseases.


Subject(s)
COVID-19 , Spike Glycoprotein, Coronavirus , Antibodies, Neutralizing/therapeutic use , Antibodies, Viral/therapeutic use , COVID-19/drug therapy , Epitopes , Humans , Membrane Glycoproteins/metabolism , Neutralization Tests , Pandemics , SARS-CoV-2 , United States , Viral Envelope Proteins/genetics
16.
Nat Commun ; 13(1): 3824, 2022 07 02.
Article in English | MEDLINE | ID: covidwho-1991580

ABSTRACT

Omicron variant strains encode large numbers of changes in the spike protein compared to historical SARS-CoV-2 isolates. Although in vitro studies have suggested that several monoclonal antibody therapies lose neutralizing activity against Omicron variants, the effects in vivo remain largely unknown. Here, we report on the protective efficacy against three SARS-CoV-2 Omicron lineage strains (BA.1, BA.1.1, and BA.2) of two monoclonal antibody therapeutics (S309 [Vir Biotechnology] monotherapy and AZD7442 [AstraZeneca] combination), which correspond to ones used to treat or prevent SARS-CoV-2 infections in humans. Despite losses in neutralization potency in cell culture, S309 or AZD7442 treatments reduced BA.1, BA.1.1, and BA.2 lung infection in susceptible mice that express human ACE2 (K18-hACE2) in prophylactic and therapeutic settings. Correlation analyses between in vitro neutralizing activity and reductions in viral burden in K18-hACE2 or human FcγR transgenic mice suggest that S309 and AZD7442 have different mechanisms of protection against Omicron variants, with S309 utilizing Fc effector function interactions and AZD7442 acting principally by direct neutralization. Our data in mice demonstrate the resilience of S309 and AZD7442 mAbs against emerging SARS-CoV-2 variant strains and provide insight into the relationship between loss of antibody neutralization potency and retained protection in vivo.


Subject(s)
COVID-19 , SARS-CoV-2 , Animals , Antibodies, Monoclonal/pharmacology , Antibodies, Monoclonal/therapeutic use , Antibodies, Neutralizing , Antibodies, Viral/therapeutic use , COVID-19/drug therapy , Drug Combinations , Humans , Membrane Glycoproteins , Mice , Neutralization Tests , Spike Glycoprotein, Coronavirus , Viral Envelope Proteins
18.
Nat Commun ; 13(1): 4480, 2022 08 02.
Article in English | MEDLINE | ID: covidwho-1967603

ABSTRACT

REGEN-COV, a combination of the monoclonal antibodies casirivimab and imdevimab, has been approved as a treatment for high-risk patients infected with SARS-CoV-2 within five days of their diagnosis. We performed a retrospective cohort study, and used data repositories of Israel's largest healthcare organization to determine the real-world effectiveness of REGEN-COV treatment against COVID-19-related hospitalization, severe disease, and death. We compared patients infected with Delta variant and treated with REGEN-COV (n = 289) to those infected but not-treated with REGEN-COV (n = 1,296). Demographic and clinical characteristics were used to match patients and for further adjustment as part of the C0x model. Estimated treatment effectiveness was defined as one minus the hazard ratio. Treatment effectiveness of REGEN-COV was 56.4% (95% CI: 23.7-75.1%) in preventing COVID-19 hospitalization, 59.2% (95% CI: 19.9-79.2%) in preventing severe COVID-19, and 93.5% (95% CI: 52.1-99.1%) in preventing COVID-19 death in the 28 days after treatment. In conclusion, REGEN-COV was effective in reducing the risk of severe sequelae in high-risk COVID-19 patients.


Subject(s)
COVID-19 , SARS-CoV-2 , Antibodies, Monoclonal, Humanized , Antibodies, Neutralizing , Antibodies, Viral/therapeutic use , COVID-19/drug therapy , Drug Combinations , Humans , Retrospective Studies
19.
Cell Res ; 32(9): 831-842, 2022 09.
Article in English | MEDLINE | ID: covidwho-1967595

ABSTRACT

SARS-CoV-2 variants with adaptive mutations have continued to emerge, causing fresh waves of infection even amongst vaccinated population. The development of broad-spectrum antivirals is thus urgently needed. We previously developed two hetero-bivalent nanobodies (Nbs), aRBD-2-5 and aRBD-2-7, with potent neutralization activity against the wild-type (WT) Wuhan isolated SARS-CoV-2, by fusing aRBD-2 with aRBD-5 and aRBD-7, respectively. Here, we resolved the crystal structures of these Nbs in complex with the receptor-binding domain (RBD) of the spike protein, and found that aRBD-2 contacts with highly-conserved RBD residues and retains binding to the RBD of the Alpha, Beta, Gamma, Delta, Delta plus, Kappa, Lambda, Omicron BA.1, and BA.2 variants. In contrast, aRBD-5 and aRBD-7 bind to less-conserved RBD epitopes non-overlapping with the epitope of aRBD-2, and do not show apparent binding to the RBD of some variants. However, when fused with aRBD-2, they effectively enhance the overall binding affinity. Consistently, aRBD-2-5-Fc and aRBD-2-7-Fc potently neutralized all of the tested authentic or pseudotyped viruses, including WT, Alpha, Beta, Gamma, Delta, and Omicron BA.1, BA.1.1 and BA.2. Furthermore, aRBD-2-5-Fc provided prophylactic protection against the WT and mouse-adapted SARS-CoV-2 in mice, and conferred protection against the Omicron BA.1 variant in hamsters prophylactically and therapeutically, indicating that aRBD-2-5-Fc could potentially benefit the prevention and treatment of COVID-19 caused by the emerging variants of concern. Our strategy provides new solutions in the development of broad-spectrum therapeutic antibodies for COVID-19.


Subject(s)
COVID-19 , Single-Domain Antibodies , Animals , Antibodies, Neutralizing , Antibodies, Viral/therapeutic use , Epitopes , Mice , Mice, Inbred BALB C , SARS-CoV-2 , Single-Domain Antibodies/pharmacology , Spike Glycoprotein, Coronavirus/genetics
20.
Immunotherapy ; 14(14): 1133-1147, 2022 10.
Article in English | MEDLINE | ID: covidwho-1963293

ABSTRACT

Background: The authors describe the developmental process of intravenous anti-COVID-19 hyperimmune immunoglobulin from anti-SARS-CoV-2 neutralizing antibody-containing plasma. Furthermore, the authors investigated its safety and protective activity in animal models. Materials & methods: The manufacturing process included standard ethanol fractionation, chromatographic purification steps and virus removal or inactivation. Results: The authors produced pure and safe immunoglobulin for intravenous administration, with 98.1 ± 6.5 mg/ml protein content, of which 97.6 ± 0.7% was IgG. The concentration factor of SARS-CoV-2 neutralizing antibodies was 9.4 ± 1.4-times. Safety studies in animals showed no signs of acute/chronic toxicity or allergenic or thrombogenic properties. Intravenous anti-COVID-19 hyperimmune immunoglobulin protected immunosuppressed hamsters against SARS-Cov-2. Conclusion: The obtained results can allow the start of clinical trials to study the safety and efficacy in healthy adults.


An intravenous immunoglobulin with a high concentration of SARS-CoV-2-neutralizing antibodies was prepared from COVID-19 convalescent plasma, which could be utilized as a passive immunization tool in regard to COVID-19 treatment. The manufacturing process employed conforms to commonly held business standards within the intravenous immunoglobulin industry and includes plasma ethanol fractionation following chromatographic purification and special virus removal or inactivation steps. The results of the preclinical in vitro and in vivo experiments demonstrate that the immunoglobulin produced in this study is pure and safe enough to be considered for intravenous applications. The SARS-CoV-2 neutralizing antibody concentration was found to have increased 9.4 ± 1.4-times compared with human plasma. The anti-COVID-19 hyperimmune immunoglobulin showed no signs of toxicity and did not cause any blood clot formations when administered to rabbits. Furthermore, the anti-COVID-19 hyperimmune immunoglobulin was demonstrated to protect immunosuppressed hamsters against SARS-CoV-2.


Subject(s)
COVID-19 , SARS-CoV-2 , Administration, Intravenous , Antibodies, Neutralizing/therapeutic use , Antibodies, Viral/therapeutic use , COVID-19/therapy , Humans , Immunization, Passive/methods , Immunoglobulins, Intravenous/therapeutic use
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