RESUMO
mRNA-1273 vaccine efficacy against SARS-CoV-2 Delta wanes over time; however, there are limited data on the impact of durability of immune responses on protection. Here, we immunized rhesus macaques and assessed immune responses over 1 year in blood and upper and lower airways. Serum neutralizing titers to Delta were 280 and 34 reciprocal ID50 at weeks 6 (peak) and 48 (challenge), respectively. Antibody-binding titers also decreased in bronchoalveolar lavage (BAL). Four days after Delta challenge, the virus was unculturable in BAL, and subgenomic RNA declined by â¼3-log10 compared with control animals. In nasal swabs, sgRNA was reduced by 1-log10, and the virus remained culturable. Anamnestic antibodies (590-fold increased titer) but not T cell responses were detected in BAL by day 4 post-challenge. mRNA-1273-mediated protection in the lungs is durable but delayed and potentially dependent on anamnestic antibody responses. Rapid and sustained protection in upper and lower airways may eventually require a boost.
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SARS-CoV-2 Omicron is highly transmissible and has substantial resistance to neutralization following immunization with ancestral spike-matched vaccines. It is unclear whether boosting with Omicron-matched vaccines would enhance protection. Here, nonhuman primates that received mRNA-1273 at weeks 0 and 4 were boosted at week 41 with mRNA-1273 or mRNA-Omicron. Neutralizing titers against D614G were 4,760 and 270 reciprocal ID50 at week 6 (peak) and week 41 (preboost), respectively, and 320 and 110 for Omicron. 2 weeks after the boost, titers against D614G and Omicron increased to 5,360 and 2,980 for mRNA-1273 boost and 2,670 and 1,930 for mRNA-Omicron, respectively. Similar increases against BA.2 were observed. Following either boost, 70%-80% of spike-specific B cells were cross-reactive against WA1 and Omicron. Equivalent control of virus replication in lower airways was observed following Omicron challenge 1 month after either boost. These data show that mRNA-1273 and mRNA-Omicron elicit comparable immunity and protection shortly after the boost.
Assuntos
COVID-19 , SARS-CoV-2 , Vacina de mRNA-1273 contra 2019-nCoV , Animais , Anticorpos Neutralizantes , Anticorpos Antivirais , COVID-19/prevenção & controle , Macaca , RNA MensageiroRESUMO
BACKGROUND: Meropenem is a broad-spectrum carbapenem-type antibiotic commonly used to treat critically ill patients infected with extended-spectrum ß-lactamase (ESBL)-producing Enterobacteriaceae. As many of these patients require extracorporeal membrane oxygenation (ECMO) and/or continuous renal replacement therapy (CRRT), it is important to understand how these extracorporeal life support circuits impact meropenem pharmacokinetics. Based on the physicochemical properties of meropenem, it is expected that ECMO circuits will minimally extract meropenem, while CRRT circuits will rapidly clear meropenem. The present study seeks to determine the extraction of meropenem from ex vivo ECMO and CRRT circuits and elucidate the contribution of different ECMO circuit components to extraction. METHODS: Standard doses of meropenem were administered to three different configurations (n = 3 per configuration) of blood-primed ex vivo ECMO circuits and serial sampling was conducted over 24 h. Similarly, standard doses of meropenem were administered to CRRT circuits (n = 4) and serial sampling was conducted over 4 h. Meropenem was administered to separate tubes primed with circuit blood to serve as controls to account for drug degradation. Meropenem concentrations were quantified, and percent recovery was calculated for each sample. RESULTS: Meropenem was cleared at a similar rate in ECMO circuits of different configurations (n = 3) and controls (n = 6), with mean (standard deviation) recovery at 24 h of 15.6% (12.9) in Complete circuits, 37.9% (8.3) in Oxygenator circuits, 47.1% (8.2) in Pump circuits, and 20.6% (20.6) in controls. In CRRT circuits (n = 4) meropenem was cleared rapidly compared with controls (n = 6) with a mean recovery at 2 h of 2.36% (1.44) in circuits and 93.0% (7.1) in controls. CONCLUSION: Meropenem is rapidly cleared by hemodiafiltration during CRRT. There is minimal adsorption of meropenem to ECMO circuit components; however, meropenem undergoes significant degradation and/or plasma metabolism at physiological conditions. These ex vivo findings will advise pharmacists and physicians on the appropriate dosing of meropenem.
Assuntos
Oxigenação por Membrana Extracorpórea , Humanos , Meropeném , Antibacterianos/farmacocinética , CarbapenêmicosRESUMO
CONTEXT: In the United States, COVID-19 vaccines have been unequally distributed between different racial and ethnic groups. Public reporting of race and ethnicity data for COVID-19 vaccination has the potential to help guide public health responses aimed at promoting vaccination equity. However, there is evidence that such data are not readily available. OBJECTIVES: This study sought to assess gaps and discrepancies in COVID-19 vaccination reporting in 10 large US cities in July 2021. DESIGN, SETTING, AND PARTICIPANTS: For the 10 cities selected, we collected COVID-19 vaccination and population data using publicly available resources, such as state health department Web sites and the US Census Bureau American Community Survey. We examined vaccination plans and news sources to identify initial proposals and evidence of implementation of COVID-19 vaccination best practices. MAIN OUTCOME MEASURE: We performed quantitative assessment of associations of the number of vaccination best practices implemented with COVID-19 racial and ethnic vaccination equity. We additionally assessed gaps and discrepancies in COVID-19 vaccination reporting between states. RESULTS: Our analysis did not show that COVID-19 vaccination inequity was associated with the number of vaccination best practices implemented. However, gaps and variation in reporting of racial and ethnic demographic vaccination data inhibited our ability to effectively assess whether vaccination programs were reaching minority populations. CONCLUSIONS: Lack of consistent public reporting and transparency of COVID-19 vaccination data has likely hindered public health responses by impeding the ability to track the effectiveness of strategies that target vaccine equity.
Assuntos
COVID-19 , Etnicidade , COVID-19/epidemiologia , COVID-19/prevenção & controle , Vacinas contra COVID-19/uso terapêutico , Cidades , Humanos , Estados Unidos/epidemiologia , VacinaçãoRESUMO
The continued evolution of SARS-CoV-2 variants capable of subverting vaccine and infection-induced immunity suggests the advantage of a broadly protective vaccine against betacoronaviruses (ß-CoVs). Recent studies have isolated monoclonal antibodies (mAbs) from SARS-CoV-2 recovered-vaccinated donors capable of neutralizing many variants of SARS-CoV-2 and other ß-CoVs. Many of these mAbs target the conserved S2 stem region of the SARS-CoV-2 spike protein, rather the receptor binding domain contained within S1 primarily targeted by current SARS-CoV-2 vaccines. One of these S2-directed mAbs, CC40.8, has demonstrated protective efficacy in small animal models against SARS-CoV-2 challenge. As the next step in the pre-clinical testing of S2-directed antibodies as a strategy to protect from SARS-CoV-2 infection, we evaluated the in vivo efficacy of CC40.8 in a clinically relevant non-human primate model by conducting passive antibody transfer to rhesus macaques (RM) followed by SARS-CoV-2 challenge. CC40.8 mAb was intravenously infused at 10mg/kg, 1mg/kg, or 0.1 mg/kg into groups (n=6) of RM, alongside one group that received a control antibody (PGT121). Viral loads in the lower airway were significantly reduced in animals receiving higher doses of CC40.8. We observed a significant reduction in inflammatory cytokines and macrophages within the lower airway of animals infused with 10mg/kg and 1mg/kg doses of CC40.8. Viral genome sequencing demonstrated a lack of escape mutations in the CC40.8 epitope. Collectively, these data demonstrate the protective efficiency of broadly neutralizing S2-targeting antibodies against SARS-CoV-2 infection within the lower airway while providing critical preclinical work necessary for the development of pan-ß-CoV vaccines.
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SARS-CoV-2 has the capacity to evolve mutations that escape vaccine- and infection-acquired immunity and antiviral drugs. A variant-agnostic therapeutic agent that protects against severe disease without putting selective pressure on the virus would thus be a valuable biomedical tool that would maintain its efficacy despite the ongoing emergence of new variants. Here, we challenge male rhesus macaques with SARS-CoV-2 Delta-the most pathogenic variant in a highly susceptible animal model. At the time of challenge, we also treat the macaques with aerosolized RBD-62, a protein developed through multiple rounds of in vitro evolution of SARS-CoV-2 RBD to acquire 1000-fold enhanced ACE2 binding affinity. RBD-62 treatment equivalently suppresses virus replication in both upper and lower airways, a phenomenon not previously observed with clinically approved vaccines. Importantly, RBD-62 does not block the development of virus-specific T- and B-cell responses and does not elicit anti-drug immunity. These data provide proof-of-concept that RBD-62 can prevent severe disease from a highly virulent variant.
Assuntos
Enzima de Conversão de Angiotensina 2 , Antivirais , COVID-19 , Macaca mulatta , SARS-CoV-2 , Replicação Viral , Animais , SARS-CoV-2/efeitos dos fármacos , SARS-CoV-2/fisiologia , SARS-CoV-2/imunologia , Enzima de Conversão de Angiotensina 2/metabolismo , Replicação Viral/efeitos dos fármacos , Masculino , COVID-19/virologia , COVID-19/imunologia , COVID-19/prevenção & controle , Humanos , Antivirais/farmacologia , Tratamento Farmacológico da COVID-19 , Glicoproteína da Espícula de Coronavírus/metabolismo , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/imunologia , Modelos Animais de Doenças , Células Vero , Chlorocebus aethiopsRESUMO
Expanding the arsenal of prophylactic approaches against SARS-CoV-2 is of utmost importance, specifically those strategies that are resistant to antigenic drift in Spike. Here, we conducted a screen of over 16,000 RNAi triggers against the SARS-CoV-2 genome, using a massively parallel assay to identify hyper-potent siRNAs. We selected Ten candidates for in vitro validation and found five siRNAs that exhibited hyper-potent activity (IC50 < 20 pM) and strong blockade of infectivity in live-virus experiments. We further enhanced this activity by combinatorial pairing of the siRNA candidates and identified cocktails that were active against multiple types of variants of concern (VOC). We then examined over 2,000 possible mutations in the siRNA target sites by using saturation mutagenesis and confirmed broad protection of the leading cocktail against future variants. Finally, we demonstrated that intranasal administration of this siRNA cocktail effectively attenuates clinical signs and viral measures of disease in the gold-standard Syrian hamster model. Our results pave the way for the development of an additional layer of antiviral prophylaxis that is orthogonal to vaccines and monoclonal antibodies.
Assuntos
COVID-19 , RNA Interferente Pequeno , SARS-CoV-2 , Animais , Cricetinae , Administração Intranasal , COVID-19/prevenção & controle , Mesocricetus , Interferência de RNA , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/uso terapêutico , SARS-CoV-2/genéticaRESUMO
SARS-CoV-2 has the capacity to evolve mutations to escape vaccine-and infection-acquired immunity and antiviral drugs. A variant-agnostic therapeutic agent that protects against severe disease without putting selective pressure on the virus would thus be a valuable biomedical tool. Here, we challenged rhesus macaques with SARS-CoV-2 Delta and simultaneously treated them with aerosolized RBD-62, a protein developed through multiple rounds of in vitro evolution of SARS-CoV-2 RBD to acquire 1000-fold enhanced ACE2 binding affinity. RBD-62 treatment gave equivalent protection in upper and lower airways, a phenomenon not previously observed with clinically approved vaccines. Importantly, RBD-62 did not block the development of memory responses to Delta and did not elicit anti-drug immunity. These data provide proof-of-concept that RBD-62 can prevent severe disease from a highly virulent variant.
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SARS-CoV-2 continues to pose a global threat, and current vaccines, while effective against severe illness, fall short in preventing transmission. To address this challenge, there's a need for vaccines that induce mucosal immunity and can rapidly control the virus. In this study, we demonstrate that a single immunization with a novel gorilla adenovirus-based vaccine (GRAd) carrying the pre-fusion stabilized Spike protein (S-2P) in non-human primates provided protective immunity for over one year against the BA.5 variant of SARS-CoV-2. A prime-boost regimen using GRAd followed by adjuvanted S-2P (GRAd+S-2P) accelerated viral clearance in both the lower and upper airways. GRAd delivered via aerosol (GRAd(AE)+S-2P) modestly improved protection compared to its matched intramuscular regimen, but showed dramatically superior boosting by mRNA and, importantly, total virus clearance in the upper airway by day 4 post infection. GrAd vaccination regimens elicited robust and durable systemic and mucosal antibody responses to multiple SARS-CoV-2 variants, but only GRAd(AE)+S-2P generated long-lasting T cell responses in the lung. This research underscores the flexibility of the GRAd vaccine platform to provide durable immunity against SARS-CoV-2 in both the lower and upper airways.
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Some G protein-coupled receptor (GPCR) ligands act as "biased agonists" that preferentially activate specific signaling transducers over others. Although GPCRs are primarily found at the plasma membrane, GPCRs can traffic to and signal from many subcellular compartments. Here, we determine that differential subcellular signaling contributes to the biased signaling generated by three endogenous ligands of the GPCR CXC chemokine receptor 3 (CXCR3). The signaling profile of CXCR3 changes as it traffics from the plasma membrane to endosomes in a ligand-specific manner. Endosomal signaling is critical for biased activation of G proteins, ß-arrestins, and extracellular-signal-regulated kinase (ERK). In CD8 + T cells, the chemokines promote unique transcriptional responses predicted to regulate inflammatory pathways. In a mouse model of contact hypersensitivity, ß-arrestin-biased CXCR3-mediated inflammation is dependent on receptor internalization. Our work demonstrates that differential subcellular signaling is critical to the overall biased response observed at CXCR3, which has important implications for drugs targeting chemokine receptors and other GPCRs.
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Proteínas de Ligação ao GTP , Receptores CXCR3 , Animais , Quimiocinas/metabolismo , Proteínas de Ligação ao GTP/metabolismo , Ligantes , Camundongos , Receptores CXCR3/genética , Receptores CXCR3/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , beta-Arrestinas/metabolismoRESUMO
In the human chemokine system, interactions between the approximately 50 known endogenous chemokine ligands and 20 known chemokine receptors (CKRs) regulate a wide range of cellular functions and biological processes including immune cell activation and homeostasis, development, angiogenesis, and neuromodulation. CKRs are a family of G protein-coupled receptors (GPCR), which represent the most common and versatile class of receptors in the human genome and the targets of approximately one third of all Food and Drug Administration-approved drugs. Chemokines and CKRs bind with significant promiscuity, as most CKRs can be activated by multiple chemokines and most chemokines can activate multiple CKRs. While these ligand-receptor interactions were previously regarded as redundant, it is now appreciated that many chemokine:CKR interactions display biased agonism, the phenomenon in which different ligands binding to the same receptor signal through different pathways with different efficacies, leading to distinct biological effects. Notably, these biased responses can be modulated through changes in ligand, receptor, and or the specific cellular context (system). In this review, we explore the biochemical mechanisms, functional consequences, and therapeutic potential of biased agonism in the chemokine system. An enhanced understanding of biased agonism in the chemokine system may prove transformative in the understanding of the mechanisms and consequences of biased signaling across all GPCR subtypes and aid in the development of biased pharmaceuticals with increased therapeutic efficacy and safer side effect profiles.
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Quimiocinas/metabolismo , Receptores de Quimiocinas/metabolismo , Transdução de Sinais , Animais , Quimiocinas/genética , Humanos , Ligantes , Receptores de Quimiocinas/genéticaRESUMO
mRNA-1273 vaccine efficacy against SARS-CoV-2 Delta wanes over time; however, there are limited data on the impact of durability of immune responses on protection. We immunized rhesus macaques at weeks 0 and 4 and assessed immune responses over one year in blood, upper and lower airways. Serum neutralizing titers to Delta were 280 and 34 reciprocal ID 50 at weeks 6 (peak) and 48 (challenge), respectively. Antibody binding titers also decreased in bronchoalveolar lavage (BAL). Four days after challenge, virus was unculturable in BAL and subgenomic RNA declined â¼3-log 10 compared to control animals. In nasal swabs, sgRNA declined 1-log 10 and virus remained culturable. Anamnestic antibody responses (590-fold increase) but not T cell responses were detected in BAL by day 4 post-challenge. mRNA-1273-mediated protection in the lungs is durable but delayed and potentially dependent on anamnestic antibody responses. Rapid and sustained protection in upper and lower airways may eventually require a boost.