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1.
Cell ; 185(11): 1875-1887.e8, 2022 05 26.
Article in English | MEDLINE | ID: covidwho-1778028

ABSTRACT

We examined antibody and memory B cell responses longitudinally for ∼9-10 months after primary 2-dose SARS-CoV-2 mRNA vaccination and 3 months after a 3rd dose. Antibody decay stabilized between 6 and 9 months, and antibody quality continued to improve for at least 9 months after 2-dose vaccination. Spike- and RBD-specific memory B cells remained durable over time, and 40%-50% of RBD-specific memory B cells simultaneously bound the Alpha, Beta, Delta, and Omicron variants. Omicron-binding memory B cells were efficiently reactivated by a 3rd dose of wild-type vaccine and correlated with the corresponding increase in neutralizing antibody titers. In contrast, pre-3rd dose antibody titers inversely correlated with the fold-change of antibody boosting, suggesting that high levels of circulating antibodies may limit the added protection afforded by repeat short interval boosting. These data provide insight into the quantity and quality of mRNA-vaccine-induced immunity over time through 3 or more antigen exposures.


Subject(s)
COVID-19 Vaccines , COVID-19 , Antibodies, Neutralizing , Antibodies, Viral , COVID-19/prevention & control , Humans , RNA, Messenger , SARS-CoV-2 , Vaccines, Synthetic , mRNA Vaccines
2.
EuropePMC;
Preprint in English | EuropePMC | ID: ppcovidwho-327778

ABSTRACT

Despite a clear role in protective immunity, the durability and quality of antibody and memory B cell responses induced by mRNA vaccination, particularly by a 3rd dose of vaccine, remains unclear. Here, we examined antibody and memory B cell responses in a cohort of individuals sampled longitudinally for ~9-10 months after the primary 2-dose mRNA vaccine series, as well as for ~3 months after a 3rd mRNA vaccine dose. Notably, antibody decay slowed significantly between 6- and 9-months post-primary vaccination, essentially stabilizing at the time of the 3rd dose. Antibody quality also continued to improve for at least 9 months after primary 2-dose vaccination. Spike- and RBD-specific memory B cells were stable through 9 months post-vaccination with no evidence of decline over time, and ~40-50% of RBD-specific memory B cells were capable of simultaneously recognizing the Alpha, Beta, Delta, and Omicron variants. Omicron-binding memory B cells induced by the first 2 doses of mRNA vaccine were boosted significantly by a 3rd dose and the magnitude of this boosting was similar to memory B cells specific for other variants. Pre-3rd dose memory B cell frequencies correlated with the increase in neutralizing antibody titers after the 3rd dose. In contrast, pre-3rd dose antibody titers inversely correlated with the fold-change of antibody boosting, suggesting that high levels of circulating antibodies may limit reactivation of immunological memory and constrain further antibody boosting by mRNA vaccines. These data provide a deeper understanding of how the quantity and quality of antibody and memory B cell responses change over time and number of antigen exposures. These data also provide insight into potential immune dynamics following recall responses to additional vaccine doses or post-vaccination infections.

3.
EuropePMC; 2020.
Preprint in English | EuropePMC | ID: ppcovidwho-317144

ABSTRACT

Background: Climate change impacts are felt disproportionately in developing countries, and in particular Southern Asia experiences the most damaging hydrometeorological events in the world, with loss of life from past cyclones in the hundreds of thousands. Despite this, the Bay of Bengal cyclone basin receives far less research attention than many of the others around the world. Here, we study the historical and future impacts of Super Cyclone Amphan, which made landfall in May 2020, bringing storm surges of 2-4 meters to coastlines of India and Bangladesh. Methods: In this modelling study, we combine projections of sea level rise from the Coupled Model Intercomparison Projection, phase 6 (CMIP6), with estimates of storm surge using a dynamic storm surge model. Sampling the spectrum of possible sea level rises, we consider a low, medium and high scenario, based on projections in 2100. We then feed these into a flood inundation model to simulate storm surge-induced flooding, had Cyclone Amphan occurred in these future worlds. Finally, we consider the change in future population growth and urbanisation, thereby calculating the change in population exposure to these future flooding events. Our approach is that of the extreme event attribution community, but projecting into the future rather than interrogating the past. Findings: We find that in 2100, the local sea level rise in the Bay of Bengal during the pre-monsoon cyclone season is between 0.32-0.84 m, depending on which emissions scenario is followed. If a Cyclone Amphan-scale storm surge occurred on top of that sea level rise, the future population of both India and Bangladesh will be more exposed, with India showing >200% increased exposure to extreme (>3 m) and moderate (>1 m) flooding under a high emissions scenario, and Bangladesh showing ~60-80% increased exposure to the same scenarios. The majority of this change in both countries comes from sea level rise rather than population changes, and in Bangladesh the future population change contributes negatively to the change in exposure, as more citizens migrate further inshore. However, if we follow an emissions scenario consistent with meeting the upper Paris Agreement climate goal, we project very little change in exposure. Interpretation: There is an urgent need to reduce carbon emissions to net zero, to prevent the negative impacts of climate change. By far the majority of cyclone research has been undertaken for countries such as America and Japan, with less resilient countries such as those in South Asia, which are more sensitive to changes in climate, seeing far less attention. With Cyclone Amphan occurring at the height of the COVID-19 crisis, we highlight how the risk was compounded and recommend that future climate risk assessments explicitly account for these potential non-linearities. Funding Statement: The main funding is from the Natural Environment Research Council.Declaration of Interests: The authors declare no competing interests.

4.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-305293

ABSTRACT

Concerns with current mRNA Lipid Nanoparticle (LNP) systems include dose-limiting reactogenicity, adverse events that may be partly due to systemic off target expression of the immunogen, and a very limited understanding of the mechanisms responsible for the frozen storage requirement. We applied a new rational design process to identify a novel multiprotic ionizable lipid, called C24, as the key component of the mRNA LNP delivery system. We show that the resulting C24 LNP has a multistage protonation behavior resulting in greater endosomal protonation and greater translation of an mRNA-encoded luciferase reporter after intramuscular (IM) administration compared to the standard reference MC3 LNP. Off-target expression in liver after IM administration was reduced 6 fold for the C24 LNP compared to MC3. Neutralizing titers in immunogenicity studies delivering a nucleoside-modified mRNA encoding for the diproline stabilized spike protein immunogen were 10 fold higher for the C24 LNP versus MC3, and protection against viral challenge in a SARS-CoV-2 mouse model occurred at a very low 0.25 µg prime/boost dose of the same immunogen in the C24 LNP. Injection site inflammation was notably reduced for C24 compared to MC3. In addition, we found the C24 LNP to be entirely stable in bioactivity and mRNA integrity when stored at 4 ºC for at least 19 days. Storage at higher temperatures reduced both bioactivity and mRNA integrity, but less so for C24 than MC3, and in a manner consistent with the phosphodiester transesterification reaction mechanism of mRNA cleavage. The higher potency, lower injection site inflammation, and higher stability of the C24 LNP present important advancements in the evolution mRNA vaccine delivery.

5.
Cell ; 185(6): 1008-1024.e15, 2022 03 17.
Article in English | MEDLINE | ID: covidwho-1664732

ABSTRACT

Vaccine-mediated immunity often relies on the generation of protective antibodies and memory B cells, which commonly stem from germinal center (GC) reactions. An in-depth comparison of the GC responses elicited by SARS-CoV-2 mRNA vaccines in healthy and immunocompromised individuals has not yet been performed due to the challenge of directly probing human lymph nodes. Herein, through a fine-needle aspiration-based approach, we profiled the immune responses to SARS-CoV-2 mRNA vaccines in lymph nodes of healthy individuals and kidney transplant recipients (KTXs). We found that, unlike healthy subjects, KTXs presented deeply blunted SARS-CoV-2-specific GC B cell responses coupled with severely hindered T follicular helper cell, SARS-CoV-2 receptor binding domain-specific memory B cell, and neutralizing antibody responses. KTXs also displayed reduced SARS-CoV-2-specific CD4 and CD8 T cell frequencies. Broadly, these data indicate impaired GC-derived immunity in immunocompromised individuals and suggest a GC origin for certain humoral and memory B cell responses following mRNA vaccination.

6.
Nat Med ; 27(11): 1990-2001, 2021 11.
Article in English | MEDLINE | ID: covidwho-1526094

ABSTRACT

SARS-CoV-2 messenger RNA vaccination in healthy individuals generates immune protection against COVID-19. However, little is known about SARS-CoV-2 mRNA vaccine-induced responses in immunosuppressed patients. We investigated induction of antigen-specific antibody, B cell and T cell responses longitudinally in patients with multiple sclerosis (MS) on anti-CD20 antibody monotherapy (n = 20) compared with healthy controls (n = 10) after BNT162b2 or mRNA-1273 mRNA vaccination. Treatment with anti-CD20 monoclonal antibody (aCD20) significantly reduced spike-specific and receptor-binding domain (RBD)-specific antibody and memory B cell responses in most patients, an effect ameliorated with longer duration from last aCD20 treatment and extent of B cell reconstitution. By contrast, all patients with MS treated with aCD20 generated antigen-specific CD4 and CD8 T cell responses after vaccination. Treatment with aCD20 skewed responses, compromising circulating follicular helper T (TFH) cell responses and augmenting CD8 T cell induction, while preserving type 1 helper T (TH1) cell priming. Patients with MS treated with aCD20 lacking anti-RBD IgG had the most severe defect in circulating TFH responses and more robust CD8 T cell responses. These data define the nature of the SARS-CoV-2 vaccine-induced immune landscape in aCD20-treated patients and provide insights into coordinated mRNA vaccine-induced immune responses in humans. Our findings have implications for clinical decision-making and public health policy for immunosuppressed patients including those treated with aCD20.


Subject(s)
COVID-19 Vaccines/therapeutic use , Multiple Sclerosis/immunology , Multiple Sclerosis/therapy , SARS-CoV-2/immunology , Animals , Antibodies, Monoclonal/therapeutic use , Antibodies, Viral/analysis , Antibodies, Viral/blood , Antigens, CD20/immunology , COVID-19/prevention & control , Case-Control Studies , Chlorocebus aethiops , HEK293 Cells , Humans , Immunity, Cellular , Immunity, Humoral/drug effects , Immunity, Humoral/physiology , Immunotherapy/methods , Longitudinal Studies , Multiple Sclerosis/blood , RNA, Messenger/immunology , RNA, Viral/immunology , Rituximab/pharmacology , Rituximab/therapeutic use , SARS-CoV-2/genetics , Vaccination , Vero Cells
7.
Immunity ; 54(12): 2877-2892.e7, 2021 12 14.
Article in English | MEDLINE | ID: covidwho-1499988

ABSTRACT

Adjuvants are critical for improving the quality and magnitude of adaptive immune responses to vaccination. Lipid nanoparticle (LNP)-encapsulated nucleoside-modified mRNA vaccines have shown great efficacy against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), but the mechanism of action of this vaccine platform is not well-characterized. Using influenza virus and SARS-CoV-2 mRNA and protein subunit vaccines, we demonstrated that our LNP formulation has intrinsic adjuvant activity that promotes induction of strong T follicular helper cell, germinal center B cell, long-lived plasma cell, and memory B cell responses that are associated with durable and protective antibodies in mice. Comparative experiments demonstrated that this LNP formulation outperformed a widely used MF59-like adjuvant, AddaVax. The adjuvant activity of the LNP relies on the ionizable lipid component and on IL-6 cytokine induction but not on MyD88- or MAVS-dependent sensing of LNPs. Our study identified LNPs as a versatile adjuvant that enhances the efficacy of traditional and next-generation vaccine platforms.


Subject(s)
B-Lymphocytes/immunology , COVID-19 Vaccines/immunology , COVID-19/immunology , Germinal Center/immunology , SARS-CoV-2/physiology , T-Lymphocytes, Helper-Inducer/immunology , /immunology , Adaptor Proteins, Signal Transducing/genetics , Adaptor Proteins, Signal Transducing/metabolism , Adjuvants, Immunologic , Animals , HEK293 Cells , Humans , Immunity, Humoral , Interleukin-6/genetics , Interleukin-6/metabolism , Liposomes/administration & dosage , Mice , Mice, Inbred BALB C , Nanoparticles/administration & dosage , Protein Subunits/genetics , /genetics
8.
Science ; 374(6572): abm0829, 2021 Dec 03.
Article in English | MEDLINE | ID: covidwho-1467659

ABSTRACT

The durability of immune memory after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) messenger RNA (mRNA) vaccination remains unclear. In this study, we longitudinally profiled vaccine responses in SARS-CoV-2­naïve and ­recovered individuals for 6 months after vaccination. Antibodies declined from peak levels but remained detectable in most subjects at 6 months. By contrast, mRNA vaccines generated functional memory B cells that increased from 3 to 6 months postvaccination, with the majority of these cells cross-binding the Alpha, Beta, and Delta variants. mRNA vaccination further induced antigen-specific CD4+ and CD8+ T cells, and early CD4+ T cell responses correlated with long-term humoral immunity. Recall responses to vaccination in individuals with preexisting immunity primarily increased antibody levels without substantially altering antibody decay rates. Together, these findings demonstrate robust cellular immune memory to SARS-CoV-2 and its variants for at least 6 months after mRNA vaccination.


Subject(s)
COVID-19 Vaccines/immunology , Immunologic Memory , SARS-CoV-2/genetics , SARS-CoV-2/immunology , /immunology , Humans
9.
Immunity ; 54(9): 2133-2142.e3, 2021 09 14.
Article in English | MEDLINE | ID: covidwho-1433401

ABSTRACT

SARS-CoV-2 mRNA vaccines have shown remarkable clinical efficacy, but questions remain about the nature and kinetics of T cell priming. We performed longitudinal antigen-specific T cell analyses on healthy SARS-CoV-2-naive and recovered individuals prior to and following mRNA prime and boost vaccination. Vaccination induced rapid antigen-specific CD4+ T cell responses in naive subjects after the first dose, whereas CD8+ T cell responses developed gradually and were variable in magnitude. Vaccine-induced Th1 and Tfh cell responses following the first dose correlated with post-boost CD8+ T cells and neutralizing antibodies, respectively. Integrated analysis revealed coordinated immune responses with distinct trajectories in SARS-CoV-2-naive and recovered individuals. Last, whereas booster vaccination improved T cell responses in SARS-CoV-2-naive subjects, the second dose had little effect in SARS-CoV-2-recovered individuals. These findings highlight the role of rapidly primed CD4+ T cells in coordinating responses to the second vaccine dose in SARS-CoV-2-naive individuals.


Subject(s)
CD8-Positive T-Lymphocytes/immunology , COVID-19 Vaccines/immunology , COVID-19/immunology , SARS-CoV-2/physiology , Th1 Cells/immunology , Adult , Antibodies, Neutralizing/blood , Antibodies, Viral/blood , Antigens, CD/metabolism , Antigens, Differentiation, T-Lymphocyte/metabolism , Female , Humans , Immunity, Cellular , Immunity, Humoral , Immunization, Secondary , Immunologic Memory , Lectins, C-Type/metabolism , Lymphocyte Activation , Male , Middle Aged , Peptides/immunology , Spike Glycoprotein, Coronavirus/immunology , Vaccination , Young Adult
10.
Nat Med ; 27(11): 1990-2001, 2021 11.
Article in English | MEDLINE | ID: covidwho-1410406

ABSTRACT

SARS-CoV-2 messenger RNA vaccination in healthy individuals generates immune protection against COVID-19. However, little is known about SARS-CoV-2 mRNA vaccine-induced responses in immunosuppressed patients. We investigated induction of antigen-specific antibody, B cell and T cell responses longitudinally in patients with multiple sclerosis (MS) on anti-CD20 antibody monotherapy (n = 20) compared with healthy controls (n = 10) after BNT162b2 or mRNA-1273 mRNA vaccination. Treatment with anti-CD20 monoclonal antibody (aCD20) significantly reduced spike-specific and receptor-binding domain (RBD)-specific antibody and memory B cell responses in most patients, an effect ameliorated with longer duration from last aCD20 treatment and extent of B cell reconstitution. By contrast, all patients with MS treated with aCD20 generated antigen-specific CD4 and CD8 T cell responses after vaccination. Treatment with aCD20 skewed responses, compromising circulating follicular helper T (TFH) cell responses and augmenting CD8 T cell induction, while preserving type 1 helper T (TH1) cell priming. Patients with MS treated with aCD20 lacking anti-RBD IgG had the most severe defect in circulating TFH responses and more robust CD8 T cell responses. These data define the nature of the SARS-CoV-2 vaccine-induced immune landscape in aCD20-treated patients and provide insights into coordinated mRNA vaccine-induced immune responses in humans. Our findings have implications for clinical decision-making and public health policy for immunosuppressed patients including those treated with aCD20.


Subject(s)
COVID-19 Vaccines/therapeutic use , Multiple Sclerosis/immunology , Multiple Sclerosis/therapy , SARS-CoV-2/immunology , Animals , Antibodies, Monoclonal/therapeutic use , Antibodies, Viral/analysis , Antibodies, Viral/blood , Antigens, CD20/immunology , COVID-19/prevention & control , Case-Control Studies , Chlorocebus aethiops , HEK293 Cells , Humans , Immunity, Cellular , Immunity, Humoral/drug effects , Immunity, Humoral/physiology , Immunotherapy/methods , Longitudinal Studies , Multiple Sclerosis/blood , RNA, Messenger/immunology , RNA, Viral/immunology , Rituximab/pharmacology , Rituximab/therapeutic use , SARS-CoV-2/genetics , Vaccination , Vero Cells
12.
Sci Immunol ; 6(58)2021 04 15.
Article in English | MEDLINE | ID: covidwho-1349998

ABSTRACT

Novel mRNA vaccines for SARS-CoV-2 have been authorized for emergency use. Despite their efficacy in clinical trials, data on mRNA vaccine-induced immune responses are mostly limited to serological analyses. Here, we interrogated antibody and antigen-specific memory B cells over time in 33 SARS-CoV-2 naïve and 11 SARS-CoV-2 recovered subjects. SARS-CoV-2 naïve individuals required both vaccine doses for optimal increases in antibodies, particularly for neutralizing titers against the B.1.351 variant. Memory B cells specific for full-length spike protein and the spike receptor binding domain (RBD) were also efficiently primed by mRNA vaccination and detectable in all SARS-CoV-2 naive subjects after the second vaccine dose, though the memory B cell response declined slightly with age. In SARS-CoV-2 recovered individuals, antibody and memory B cell responses were significantly boosted after the first vaccine dose; however, there was no increase in circulating antibodies, neutralizing titers, or antigen-specific memory B cells after the second dose. This robust boosting after the first vaccine dose strongly correlated with levels of pre-existing memory B cells in recovered individuals, identifying a key role for memory B cells in mounting recall responses to SARS-CoV-2 antigens. Together, our data demonstrated robust serological and cellular priming by mRNA vaccines and revealed distinct responses based on prior SARS-CoV-2 exposure, whereby COVID-19 recovered subjects may only require a single vaccine dose to achieve peak antibody and memory B cell responses. These findings also highlight the utility of defining cellular responses in addition to serologies and may inform SARS-CoV-2 vaccine distribution in a resource-limited setting.


Subject(s)
Antibodies, Viral/immunology , B-Lymphocytes/immunology , COVID-19 Vaccines , COVID-19/immunology , SARS-CoV-2/immunology , Vaccines, Synthetic , Adult , Antibodies, Neutralizing/immunology , Antibodies, Viral/blood , Female , Humans , Male , Middle Aged , RNA, Messenger , Spike Glycoprotein, Coronavirus/immunology , Vaccination , Young Adult
13.
J Pediatric Infect Dis Soc ; 10(5): 669-673, 2021 May 28.
Article in English | MEDLINE | ID: covidwho-1262143

ABSTRACT

Severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) antibody responses in children remain poorly characterized. Here, we show that pediatric patients with multisystem inflammatory syndrome in children (MIS-C) possess higher SARS-CoV-2 spike immunoglobulin G (IgG) titers compared with those with severe coronavirus disease 2019, likely reflecting a longer time since the onset of infection in MIS-C patients.


Subject(s)
Antibodies, Viral/immunology , Antibody Formation , COVID-19/immunology , Spike Glycoprotein, Coronavirus/immunology , Systemic Inflammatory Response Syndrome/immunology , COVID-19 Serological Testing , Child , Female , Humans , Immunoglobulin A/immunology , Immunoglobulin G/immunology , Immunoglobulin M/immunology , Male , SARS-CoV-2 , Severity of Illness Index
14.
Journal of Air Transport Management ; : 102081, 2021.
Article in English | ScienceDirect | ID: covidwho-1213312

ABSTRACT

This study investigates Australian undergraduate tertiary aviation students' perceptions of the aviation industry and skills required to succeed following the COVID-19 pandemic. By developing an understanding of the skills students perceive to be necessary for their careers following the COVID-19 pandemic, comparisons can be drawn with industry perspectives to determine whether these perspectives align and, more importantly, support students’ successful development of skills as sought by the industry. An online survey of current undergraduate tertiary aviation students at Australian universities was conducted to determine the perceived impediments, additional skills required, post-graduation plans and how university courses should evolve post-COVID-19. The results show that students are cognisant of the current oversupply of aviation professionals due to the downturn in the industry and are seeking further support with the development of non-technical skills to better prepare themselves to be competitive following graduation. These findings have implications for both undergraduate aviation students and universities offering an undergraduate aviation program. By considering these findings universities can adapt their programs to better prepare students and support the development of skilled aviation professionals, equipped to deal with challenges of the post-COVID-19 aviation industry.

15.
Cell ; 184(7): 1858-1864.e10, 2021 04 01.
Article in English | MEDLINE | ID: covidwho-1071140

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has rapidly spread within the human population. Although SARS-CoV-2 is a novel coronavirus, most humans had been previously exposed to other antigenically distinct common seasonal human coronaviruses (hCoVs) before the coronavirus disease 2019 (COVID-19) pandemic. Here, we quantified levels of SARS-CoV-2-reactive antibodies and hCoV-reactive antibodies in serum samples collected from 431 humans before the COVID-19 pandemic. We then quantified pre-pandemic antibody levels in serum from a separate cohort of 251 individuals who became PCR-confirmed infected with SARS-CoV-2. Finally, we longitudinally measured hCoV and SARS-CoV-2 antibodies in the serum of hospitalized COVID-19 patients. Our studies indicate that most individuals possessed hCoV-reactive antibodies before the COVID-19 pandemic. We determined that ∼20% of these individuals possessed non-neutralizing antibodies that cross-reacted with SARS-CoV-2 spike and nucleocapsid proteins. These antibodies were not associated with protection against SARS-CoV-2 infections or hospitalizations, but they were boosted upon SARS-CoV-2 infection.


Subject(s)
Alphacoronavirus/immunology , Antibodies, Viral , Betacoronavirus/immunology , COVID-19/immunology , Adolescent , Adult , Animals , Antibodies, Viral/blood , Antibodies, Viral/immunology , COVID-19 Serological Testing , Child , Child, Preschool , Chlorocebus aethiops , Cross Protection , Cross Reactions , Disease Susceptibility , HEK293 Cells , Humans , Infant , Infant, Newborn , Vero Cells
16.
Nat Commun ; 12(1): 469, 2021 01 20.
Article in English | MEDLINE | ID: covidwho-1039642

ABSTRACT

Antibody cocktails represent a promising approach to prevent SARS-CoV-2 escape. The determinants for selecting antibody combinations and the mechanism that antibody cocktails prevent viral escape remain unclear. We compared the critical residues in the receptor-binding domain (RBD) used by multiple neutralizing antibodies and cocktails and identified a combination of two antibodies CoV2-06 and CoV2-14 for preventing viral escape. The two antibodies simultaneously bind to non-overlapping epitopes and independently compete for receptor binding. SARS-CoV-2 rapidly escapes from individual antibodies by generating resistant mutations in vitro, but it doesn't escape from the cocktail due to stronger mutational constraints on RBD-ACE2 interaction and RBD protein folding requirements. We also identified a conserved neutralizing epitope shared between SARS-CoV-2 and SARS-CoV for antibody CoV2-12. Treatments with CoV2-06 and CoV2-14 individually and in combination confer protection in mice. These findings provide insights for rational selection and mechanistic understanding of antibody cocktails as candidates for treating COVID-19.


Subject(s)
Antibodies, Monoclonal/pharmacology , COVID-19/drug therapy , SARS-CoV-2/drug effects , Angiotensin-Converting Enzyme 2/metabolism , Animals , Antibodies, Monoclonal/chemistry , Antibodies, Monoclonal/immunology , Antibodies, Neutralizing/immunology , Antibodies, Viral/genetics , Antibodies, Viral/immunology , COVID-19/virology , Chlorocebus aethiops , Disease Models, Animal , Female , Humans , Immunoglobulin Fragments/genetics , Immunoglobulin Fragments/immunology , Immunoglobulin G/genetics , Immunoglobulin G/immunology , Mice , Mice, Inbred BALB C , Models, Molecular , Mutation , Protein Binding , SARS-CoV-2/genetics , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/immunology , Vero Cells
17.
Immunity ; 53(6): 1281-1295.e5, 2020 12 15.
Article in English | MEDLINE | ID: covidwho-967679

ABSTRACT

The deployment of effective vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is critical to eradicate the coronavirus disease 2019 (COVID-19) pandemic. Many licensed vaccines confer protection by inducing long-lived plasma cells (LLPCs) and memory B cells (MBCs), cell types canonically generated during germinal center (GC) reactions. Here, we directly compared two vaccine platforms-mRNA vaccines and a recombinant protein formulated with an MF59-like adjuvant-looking for their abilities to quantitatively and qualitatively shape SARS-CoV-2-specific primary GC responses over time. We demonstrated that a single immunization with SARS-CoV-2 mRNA, but not with the recombinant protein vaccine, elicited potent SARS-CoV-2-specific GC B and T follicular helper (Tfh) cell responses as well as LLPCs and MBCs. Importantly, GC responses strongly correlated with neutralizing antibody production. mRNA vaccines more efficiently induced key regulators of the Tfh cell program and influenced the functional properties of Tfh cells. Overall, this study identifies SARS-CoV-2 mRNA vaccines as strong candidates for promoting robust GC-derived immune responses.


Subject(s)
Antibodies, Neutralizing/metabolism , B-Lymphocytes/immunology , COVID-19 Vaccines/immunology , COVID-19/immunology , Germinal Center/immunology , SARS-CoV-2/physiology , T-Lymphocytes, Helper-Inducer/immunology , Vaccines, Synthetic/immunology , Antigens, Viral/genetics , Antigens, Viral/immunology , Cells, Cultured , Epitopes , Humans , Lymphocyte Activation , Polysorbates , RNA, Viral/immunology , Recombinant Proteins/genetics , Recombinant Proteins/immunology , Squalene , Vaccination
18.
medRxiv ; 2020 Aug 18.
Article in English | MEDLINE | ID: covidwho-900749

ABSTRACT

SARS-CoV-2 antibody responses in children remain poorly characterized. Here, we show that pediatric patients with multisystem inflammatory syndrome in children (MIS-C) possess higher SARS-CoV-2 spike IgG titers compared to those with severe coronavirus disease 2019 (COVID-19), likely reflecting a longer time since onset of infection in MIS-C patients.

19.
J Am Chem Soc ; 142(40): 17024-17038, 2020 10 07.
Article in English | MEDLINE | ID: covidwho-772998

ABSTRACT

Broad-spectrum antivirals are powerful weapons against dangerous viruses where no specific therapy exists, as in the case of the ongoing SARS-CoV-2 pandemic. We discovered that a lysine- and arginine-specific supramolecular ligand (CLR01) destroys enveloped viruses, including HIV, Ebola, and Zika virus, and remodels amyloid fibrils in semen that promote viral infection. Yet, it is unknown how CLR01 exerts these two distinct therapeutic activities. Here, we delineate a novel mechanism of antiviral activity by studying the activity of tweezer variants: the "phosphate tweezer" CLR01, a "carboxylate tweezer" CLR05, and a "phosphate clip" PC. Lysine complexation inside the tweezer cavity is needed to antagonize amyloidogenesis and is only achieved by CLR01. Importantly, CLR01 and CLR05 but not PC form closed inclusion complexes with lipid head groups of viral membranes, thereby altering lipid orientation and increasing surface tension. This process disrupts viral envelopes and diminishes infectivity but leaves cellular membranes intact. Consequently, CLR01 and CLR05 display broad antiviral activity against all enveloped viruses tested, including herpesviruses, Measles virus, influenza, and SARS-CoV-2. Based on our mechanistic insights, we potentiated the antiviral, membrane-disrupting activity of CLR01 by introducing aliphatic ester arms into each phosphate group to act as lipid anchors that promote membrane targeting. The most potent ester modifications harbored unbranched C4 units, which engendered tweezers that were approximately one order of magnitude more effective than CLR01 and nontoxic. Thus, we establish the mechanistic basis of viral envelope disruption by specific tweezers and establish a new class of potential broad-spectrum antivirals with enhanced activity.


Subject(s)
Antiviral Agents/chemistry , Antiviral Agents/pharmacology , Bridged-Ring Compounds/pharmacology , Organophosphates/pharmacology , Viral Envelope Proteins/drug effects , Acid Phosphatase/chemistry , Acid Phosphatase/metabolism , Amyloid/antagonists & inhibitors , Anti-HIV Agents/chemistry , Anti-HIV Agents/pharmacology , Arginine/chemistry , Betacoronavirus/drug effects , Bridged-Ring Compounds/chemistry , Cell Membrane/chemistry , Cell Membrane/drug effects , Cell Membrane/virology , HIV Infections/drug therapy , HIV-1/drug effects , Humans , Lipids/chemistry , Lysine/chemistry , Magnetic Resonance Spectroscopy , Organophosphates/chemistry , SARS-CoV-2 , Seminal Vesicle Secretory Proteins/chemistry , Seminal Vesicle Secretory Proteins/metabolism , Structure-Activity Relationship , Viral Envelope Proteins/metabolism , Zika Virus/drug effects
20.
Immunity ; 53(4): 724-732.e7, 2020 10 13.
Article in English | MEDLINE | ID: covidwho-710374

ABSTRACT

SARS-CoV-2 infection has emerged as a serious global pandemic. Because of the high transmissibility of the virus and the high rate of morbidity and mortality associated with COVID-19, developing effective and safe vaccines is a top research priority. Here, we provide a detailed evaluation of the immunogenicity of lipid nanoparticle-encapsulated, nucleoside-modified mRNA (mRNA-LNP) vaccines encoding the full-length SARS-CoV-2 spike protein or the spike receptor binding domain in mice. We demonstrate that a single dose of these vaccines induces strong type 1 CD4+ and CD8+ T cell responses, as well as long-lived plasma and memory B cell responses. Additionally, we detect robust and sustained neutralizing antibody responses and the antibodies elicited by nucleoside-modified mRNA vaccines do not show antibody-dependent enhancement of infection in vitro. Our findings suggest that the nucleoside-modified mRNA-LNP vaccine platform can induce robust immune responses and is a promising candidate to combat COVID-19.


Subject(s)
Antibodies, Neutralizing/biosynthesis , Antibodies, Viral/biosynthesis , Betacoronavirus/drug effects , Coronavirus Infections/prevention & control , Pandemics/prevention & control , Pneumonia, Viral/prevention & control , RNA, Messenger/immunology , RNA, Viral/immunology , Viral Vaccines/administration & dosage , Animals , B-Lymphocytes/drug effects , B-Lymphocytes/immunology , B-Lymphocytes/virology , Betacoronavirus/immunology , Betacoronavirus/pathogenicity , CD4-Positive T-Lymphocytes/drug effects , CD4-Positive T-Lymphocytes/immunology , CD4-Positive T-Lymphocytes/virology , CD8-Positive T-Lymphocytes/drug effects , CD8-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/virology , COVID-19 , COVID-19 Vaccines , Coronavirus Infections/genetics , Coronavirus Infections/immunology , Coronavirus Infections/pathology , Disease Models, Animal , Furin/genetics , Furin/immunology , Humans , Immunity, Humoral/drug effects , Immunization/methods , Immunogenicity, Vaccine , Immunologic Memory/drug effects , Lymphocyte Activation/drug effects , Mice , Mice, Inbred BALB C , Nanoparticles/administration & dosage , Nanoparticles/chemistry , Pneumonia, Viral/immunology , Pneumonia, Viral/pathology , RNA, Messenger/genetics , RNA, Viral/genetics , SARS-CoV-2 , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/immunology , Vaccines, Synthetic , Viral Vaccines/biosynthesis , Viral Vaccines/genetics
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