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1.
bioRxiv ; 2022 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-36299426

RESUMO

Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2), the causative agent of Coronavirus disease 2019 (COVID-19), emerged in Wuhan, China, in December 2019. As of October 2022, there have been over 625 million confirmed cases of COVID-19, including over 6.5 million deaths. Epidemiological studies have indicated that comorbidities of obesity and diabetes mellitus are associated with increased morbidity and mortality following SARS-CoV-2 infection. We determined how the comorbidities of obesity and diabetes affect morbidity and mortality following SARS-CoV-2 infection in unvaccinated and adjuvanted spike nanoparticle (NVX-CoV2373) vaccinated mice. We find that obese/diabetic mice infected with SARS-CoV-2 have increased morbidity and mortality compared to age matched normal mice. Mice fed a high-fat diet (HFD) then vaccinated with NVX-CoV2373 produce equivalent neutralizing antibody titers to those fed a normal diet (ND). However, the HFD mice have reduced viral clearance early in infection. Analysis of the inflammatory immune response in HFD mice demonstrates a recruitment of neutrophils that was correlated with increased mortality and reduced clearance of the virus. This model recapitulates the increased disease severity associated with obesity and diabetes in humans with COVID-19 and is an important comorbidity to study with increasing obesity and diabetes across the world.

2.
medRxiv ; 2022 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-36172135

RESUMO

BACKGROUND: Over 20% of cases and 0.4% of deaths from Covid-19 occur in children. Following demonstration of safety and efficacy of the adjuvanted, recombinant spike protein vaccine NVX-CoV2373 in adults, the PREVENT-19 trial enrolled adolescents. METHODS: Safety, immunogenicity, and efficacy of NVX-CoV2373 were evaluated in adolescents aged 12 to <18 years in an expansion of PREVENT-19, a phase 3, randomized, observer-blinded, placebo-controlled trial in the United States. Participants were randomized 2:1 to two doses of NVX-CoV2373 or placebo 21 days apart, and followed for a median of 2 months after second vaccination. Primary end points were serologic non-inferiority of neutralizing antibody (NA) responses compared with young adults (18 to <26 years) in PREVENT-19, protective efficacy against laboratory-confirmed Covid-19, and assessment of reactogenicity/safety. RESULTS: Among 2,247 participants randomized between April-June 2021, 1,491 were allocated to NVX-CoV2373 and 756 to placebo. Post-vaccination, the ratio of NA geometric mean titers in adolescents compared to young adults was 1.5 (95% confidence interval [CI] 1.3 to 1.7). Twenty Covid-19 cases (all mild) occurred: 6 among NVX-CoV2373 and 14 among placebo recipients (vaccine efficacy [VE]: 79.5%, 95% CI, 46.8 to 92.1). All sequenced viral genomes (11/20) were identified as Delta variant (Delta variant VE: 82.0% [95% CI: 32.4 to 95.2]). Reactogenicity was largely mild-to-moderate, transient, and more frequent in NVX-CoV2373 recipients and after the second dose. Serious adverse events were rare and evenly distributed between treatments. CONCLUSIONS: NVX-CoV2373 was safe, immunogenic, and efficacious in the prevention of Covid-19 and those cases caused by the Delta variant in adolescents. (Funded by the Office of the Assistant Secretary for Preparedness and Response, Biomedical Advanced Research and Development Authority and the National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health; PREVENT-19 ClinicalTrials.gov number, NCT04611802 ).

3.
J Am Dent Assoc ; 153(10): 970-978.e4, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35953306

RESUMO

BACKGROUND: School sealant programs (SSPs) increase sealant prevalence among children lacking access to oral health care. SSPs, however, are substantially underused. From 2013 through 2018, the Centers for Disease Control and Prevention funded 18 states for SSP activities in high-need schools (≥ 50% free and reduced-price meal program participation). From 2019 through 2020, the authors assessed SSPs' impact in reducing caries and how states expanded SSPs. The authors also discuss potential barriers to expansion. METHODS: For Aim 1, the authors used a published methodology and SSP baseline screening and 1-year retention data to estimate averted caries over 9 years attributable to SSPs. For Aim 2, the authors used state responses to an online survey, phone interviews, and annual administrative reports. RESULTS: Using data for 62,750 children attending 18.6% of high-need schools in 16 states, the authors estimated that 7.5% of sound, unsealed molars would develop caries annually without sealants and placing 4 sealants would prevent caries in 1 molar. Fourteen states reported SSP expansion in high-need schools. The 2 most frequently reported barriers to SSP expansion were levels of funding and policies requiring dentists to be present at assessment or sealant placement. CONCLUSIONS: The authors found that SSPs typically served children at elevated caries risk and reduced caries. In addition, the authors identified funding levels and policies governing supervision of dental hygienists as possible barriers to SSP expansion. PRACTICAL IMPLICATIONS: Increasing SSP prevalence could reduce caries. Further research on potential barriers to SSP implementation identified in this study could provide critical information for long-term SSP sustainability.


Assuntos
Cárie Dentária , Selantes de Fossas e Fissuras , Adolescente , Criança , Cárie Dentária/epidemiologia , Cárie Dentária/prevenção & controle , Humanos , Dente Molar , Saúde Bucal , Selantes de Fossas e Fissuras/uso terapêutico , Instituições Acadêmicas
4.
Lancet Infect Dis ; 22(11): 1565-1576, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35963274

RESUMO

BACKGROUND: Emerging SARS-CoV-2 variants and evidence of waning vaccine efficacy present substantial obstacles towards controlling the COVID-19 pandemic. Booster doses of SARS-CoV-2 vaccines might address these concerns by amplifying and broadening the immune responses seen with initial vaccination regimens. We aimed to assess the immunogenicity and safety of a homologous booster dose of a SARS-CoV-2 recombinant spike protein vaccine (NVX-CoV2373). METHODS: This secondary analysis of a phase 2, randomised study assessed a single booster dose of a SARS-CoV-2 recombinant spike protein vaccine with Matrix-M adjuvant (NVX-CoV2373) in healthy adults aged 18-84 years, recruited from 17 clinical centres in the USA and Australia. Eligible participants had a BMI of 17-35 kg/m2 and, for women, were heterosexually inactive or using contraception. Participants who had a history of SARS-CoV or SARS-CoV-2, confirmed diagnosis of COVID-19, serious chronic medical conditions, or were pregnant or breastfeeding were excluded. Approximately 6 months following their primary two-dose vaccination series (administered day 0 and day 21), participants who received placebo for their primary vaccination series received a placebo booster (group A) and participants who received NVX-CoV2373 for their primary vaccination series (group B) were randomly assigned (1:1) again, via centralised interactive response technology system, to receive either placebo (group B1) or a single booster dose of NVX-CoV2373 (5 µg SARS-CoV-2 rS with 50 µg Matrix-M adjuvant; group B2) via intramuscular injection; randomisation was stratified by age and study site. Vaccinations were administered by designated site personnel who were masked to treatment assignment, and participants and other site staff were also masked. Administration personnel also assessed the outcome. The primary endpoints are safety (unsolicited adverse events) and reactogenicity (solicited local and systemic) events and immunogenicity (serum IgG antibody concentrations for the SARS-CoV-2 rS protein antigen) assessed 14 days after the primary vaccination series (day 35) and 28 days following booster (day 217). Safety was analysed in all participants in groups A, B1, and B2, according to the treatment received; immunogenicity was analysed in the per-protocol population (ie, participants in groups A, B1, and B2) who received all assigned doses and who did not test SARS-CoV-2-positive or received an authorised vaccine, analysed according to treatment assignment). This trial is registered with ClinicalTrials.gov, NCT04368988. FINDINGS: 1610 participants were screened from Aug 24, 2020, to Sept 25, 2020. 1282 participants were enrolled, of whom 173 were assigned again to placebo (group A), 106 were re-randomised to NVX-CoV2373-placebo (group B1), and 104 were re-randomised to NVX-CoV2373-NVX-CoV2373 (group B2); after accounting for exclusions and incorrect administration, 172 participants in group A, 102 in group B1, and 105 in group B2 were analysed for safety. Following the active booster, the proportion of participants with available data reporting local (80 [82%] of 97 participants had any adverse event; 13 [13%] had a grade ≥3 event) and systemic (75 [77%] of 98 participants had any adverse event; 15 [15%] had a grade ≥3 event) reactions was higher than after primary vaccination (175 [70%] of 250 participants had any local adverse event, 13 [5%] had a grade ≥3 event; 132 [53%] of 250 had any systemic adverse event, 14 [6%] had a grade ≥3 event). Local and systemic events were transient in nature (median duration 1·0-2·5 days). In the per-protocol immunogenicity population at day 217 (167 participants in group A, 101 participants in group B1, 101 participants in group B2), IgG geometric mean titres (GMT) had increased by 4·7-fold and MN50 GMT by 4·1-fold for the ancestral SARS-CoV-2 strain compared with the day 35 titres. INTERPRETATION: Administration of a booster dose of NVX-CoV2373 resulted in an incremental increase in reactogenicity. For both the prototype strain and all variants evaluated, immune responses following the booster were similar to or higher than those associated with high levels of efficacy in phase 3 studies of the vaccine. These data support the use of NVX-CoV2373 in booster programmes. FUNDING: Novavax and the Coalition for Epidemic Preparedness Innovations.


Assuntos
COVID-19 , Vacinas , Adulto , Feminino , Humanos , Vacinas contra COVID-19/efeitos adversos , Glicoproteína da Espícula de Coronavírus/genética , SARS-CoV-2/genética , Pandemias/prevenção & controle , Imunogenicidade da Vacina , COVID-19/prevenção & controle , Adjuvantes Imunológicos , Método Duplo-Cego , Anticorpos Antivirais
5.
Vaccines (Basel) ; 10(8)2022 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-36016226

RESUMO

Non-human primate (NHP) efficacy data for several Ebola virus (EBOV) vaccine candidates exist, but definitive correlates of protection (CoP) have not been demonstrated, although antibodies to the filovirus glycoprotein (GP) antigen and other immunological endpoints have been proposed as potential CoPs. Accordingly, studies that could elucidate biomarker(s) that statistically correlate, whether mechanistically or not, with protection are warranted. The primary objective of this study was to evaluate potential CoP for Novavax EBOV GP vaccine candidate administered at different doses to cynomolgus macaques using the combined data from two separate, related studies containing a total of 44 cynomolgus macaques. Neutralizing antibodies measured by pseudovirion neutralization assay (PsVNA) and anti-GP IgG binding antibodies were evaluated as potential CoP using logistic regression models. The predictive ability of these models was assessed using the area under the receiver operating characteristic (ROC) curve (AUC). Fitted models indicated a statistically significant relationship between survival and log base 10 (log10) transformed anti-GP IgG antibodies, with good predictive ability of the model. Neither (log10 transformed) PsVNT50 nor PsVNT80 titers were statistically significant predictors of survival, though predictive ability of both models was good. Predictive ability was not statistically different between any pair of models. Models that included immunization dose in addition to anti-GP IgG antibodies failed to detect statistically significant effects of immunization dose. These results support anti-GP IgG antibodies as a correlate of protection. Total assay variabilities and geometric coefficients of variation (GCVs) based on the study data appeared to be greater for both PsVNA readouts, suggesting the increased assay variability may account for non-significant model results for PsVNA despite the good predictive ability of the models. The statistical approach to evaluating CoP for this EBOV vaccine may prove useful for advancing research for Sudan virus (SUDV) and Marburg virus (MARV) candidate vaccines.

6.
Transfusion ; 62(4): 848-856, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35211976

RESUMO

BACKGROUND: A reliable rapid method for measuring total nucleated cell (TNC) viability is essential for cell-based products manufacturing. The trypan blue (TB) exclusion method, commonly used to measure TNC viability of hematopoietic progenitor cell (HPC) products, is a subjective assay, typically uses a microscope, and includes a limited number of cells. The NucleoCounter NC-200 is an automated fluorescent-based cell counter that uses pre-calibrated cartridges with acridine orange and DAPI dyes to measure cell count and viability. This study describes the validation of the NC-200 for testing HPC's viability. METHODS: Samples from 189 fresh and 60 cryopreserved HPC products were included. Fresh products were tested for viability after collection by both TB and NC-200. 7-aminoactinomycin D (7AAD) CD45+ cell viability results were obtained from a flow cytometry test. Cryopreserved products thawed specimens were tested for viability by both TB and NC-200. The NC-200 viability results were compared with the other methods. Acceptability criteria were defined as ≤10% difference between the NC-200 method and the other methods for at least 95% of the samples. RESULTS: Fresh products' mean viability difference between NC-200 and TB or 7AAD CD45+ method was 4.9% (95%CI 4.6-5.4) and 2.8% (95%CI 2.2-3.4), respectively. Thawed products' mean viability difference between NC-200 and TB was 3.0% (95%CI 0.4-5.6). CONCLUSION: The NC-200 automated fluorescent-based method can be used effectively to determine HPC's viability for both fresh and cryopreserved products. It can help eliminate human bias and provide consistent data and operational ease.


Assuntos
Criopreservação , Células-Tronco Hematopoéticas , Sobrevivência Celular , Corantes , Criopreservação/métodos , Humanos , Tecnologia
7.
Lancet Infect Dis ; 22(1): 73-84, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34563277

RESUMO

BACKGROUND: Improved seasonal influenza vaccines for older adults that can induce broadly cross-reactive antibodies and enhanced T-cell responses, particularly against A H3N2 viruses, while avoiding egg-adaptive antigenic changes, are needed. We aimed to show that the Matrix-M-adjuvanted quadrivalent nanoparticle influenza vaccine (qNIV) was immunologically non-inferior to a licensed, standard-dose quadrivalent inactivated influenza vaccine (IIV4) in older adults. METHODS: This was a phase 3 randomised, observer-blinded, active-comparator controlled trial done across 19 US community-based clinical research sites during the 2019-20 influenza season. Participants were clinically stable and community-dwelling, aged at least 65 years, and were randomised in a 1:1 ratio using an interactive web response system to receive a single intramuscular dose of qNIV or IIV4. The primary objective was to describe safety and show that qNIV was immunologically non-inferior to IIV4. The primary outcomes were adverse events by treatment group and comparative haemagglutination-inhibiting antibody responses (assayed with egg-propagated virus) on day 28, summarised in terms of the ratio of geometric mean titres (GMTRqNIV/IIV4) and seroconversion rate (SCR) difference between participants receiving qNIV or IIV4 for all four vaccine homologous influenza strains. The immunogenicity outcome was measured in the per-protocol population. Non-inferiority was shown if the lower bound of the two-sided 95% CI on the GMTRqNIV/IIV4 was at least 0·67 and the lower bound of the two-sided 95% CI on the SCR difference -was at least -10%. The study is registered with clinicaltrials.gov, NCT04120194, and is active and not recruiting. FINDINGS: 2742 adults were assessed for eligibility and 2654 were enrolled and randomised between Oct 14, 2019, and Oct 25, 2019; 1333 participants were randomised to the qNIV group and 1319 to the IIV4 group (two participants withdrew consent before being assigned to a group). qNIV showed immunological non-inferiority to IIV4: GMTRqNIV/IIV4 for the four vaccine homologous influenza strains was A/Brisbane 1·09 (95% CI 1·03 to 1·15), A/Kansas 1·19 (1·11 to 1·27), B/Maryland 1·03 (0·99 to 1·07), and B/Phuket 1·23 (1·16 to 1·29); and SCR difference was A/Brisbane 5·0 (95% CI 1·9 to 8·1), A/Kansas 7·3 (3·6 to 11·1), B/Maryland 0·5 (-1·9 to 2·9), and B/Phuket 8·5 (5·0 to 11·9). 659 (49·4%) of 1333 of participants in the qNIV group and 551 (41·8%) of 1319 participants in the IIV4 group had at least one treatment-emergent adverse event. More solicited adverse events were reported by participants in the qNIV group (551 [41·3%] of 1333) than in the IIV4 group (420 [31·8%] of 1319), and were comprised primarily of mild to moderate transient injection site pain (341 [25·6%] in the qNIV group vs 212 [16·1%] in the IIV4 group). INTERPRETATION: qNIV was well tolerated and produced qualitatively and quantitatively enhanced humoral and cellular immune response in older adults compared with IIV4. qNIV might enhance the effectiveness of seasonal influenza vaccination, and future studies to show clinical efficacy are planned. FUNDING: Novavax.


Assuntos
/administração & dosagem , Anticorpos Antivirais/sangue , Imunogenicidade da Vacina , Vacinas contra Influenza/imunologia , Vacinas contra Influenza/normas , Influenza Humana/prevenção & controle , Nanopartículas/administração & dosagem , Saponinas/administração & dosagem , Idoso , Feminino , Testes de Inibição da Hemaglutinação , Humanos , Vacinas contra Influenza/administração & dosagem , Influenza Humana/imunologia , Masculino , Nanopartículas/química , Saponinas/química , Estações do Ano
8.
Cell Rep Med ; 2(9): 100405, 2021 09 21.
Artigo em Inglês | MEDLINE | ID: mdl-34485950

RESUMO

Recently approved vaccines have shown remarkable efficacy in limiting SARS-CoV-2-associated disease. However, with the variety of vaccines, immunization strategies, and waning antibody titers, defining the correlates of immunity across a spectrum of antibody titers is urgently required. Thus, we profiled the humoral immune response in a cohort of non-human primates immunized with a recombinant SARS-CoV-2 spike glycoprotein (NVX-CoV2373) at two doses, administered as a single- or two-dose regimen. Both antigen dose and boosting significantly altered neutralization titers and Fc-effector profiles, driving unique vaccine-induced antibody fingerprints. Combined differences in antibody effector functions and neutralization were associated with distinct levels of protection in the upper and lower respiratory tract. Moreover, NVX-CoV2373 elicited antibodies that functionally targeted emerging SARS-CoV-2 variants. Collectively, the data presented here suggest that a single dose may prevent disease via combined Fc/Fab functions but that two doses may be essential to block further transmission of SARS-CoV-2 and emerging variants.


Assuntos
Vacinas contra COVID-19/imunologia , SARS-CoV-2/imunologia , Saponinas/imunologia , Animais , Anticorpos Neutralizantes/efeitos dos fármacos , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , COVID-19/imunologia , COVID-19/virologia , Relação Dose-Resposta Imunológica , Feminino , Imunidade Humoral/imunologia , Imunogenicidade da Vacina , Fragmentos Fab das Imunoglobulinas/imunologia , Fragmentos Fc das Imunoglobulinas/imunologia , Macaca mulatta , Masculino , Nanopartículas , Primatas/imunologia , SARS-CoV-2/patogenicidade , Glicoproteína da Espícula de Coronavírus , Vacinação
9.
Prev Chronic Dis ; 18: E72, 2021 07 22.
Artigo em Inglês | MEDLINE | ID: mdl-34296994

RESUMO

INTRODUCTION: Poor oral health affects overall health. Chronic diseases and related risk factors such as tobacco use or consuming sugar-sweetened beverages can also increase a person's risk of periodontitis. Given the linkages between oral health and certain chronic diseases, we conducted a pilot study to facilitate intradepartmental collaborations between state chronic disease and oral health programs. METHODS: State health departments in 6 states (Alaska, Colorado, Georgia, Maryland, Minnesota, and New York) collaborated to develop and implement projects that addressed oral health and the following chronic diseases or risk factors: obesity, diabetes, heart disease, stroke, and tobacco use. States developed various projects, including media campaigns, clinical education, and screening and referrals. We used a mixed-methods approach to understand barriers to and facilitators of states' increasing collaboration and implementation of pilot projects. In-depth interviews were conducted with 12 staff (1 from oral health and 1 from chronic disease for each state). We also reviewed state-submitted documents and performance measures. RESULTS: All 6 states increased collaboration between their oral health and chronic disease programs and successfully implemented pilot projects. Collaboration was facilitated by investing in relationships, championing medical-dental integration, and meeting and communicating frequently. Barriers to collaboration included the perception of oral health in chronic disease programs as separate and distinct from other chronic diseases and the structure of funding. The pilot projects were facilitated by partner support, providing technical assistance to clinics, and working early on referral networks. Barriers to implementing the pilot projects included gaining clinician buy-in and establishing referral networks. CONCLUSION: This pilot study demonstrated that by fostering collaboration, state health departments are able to train dental and medical clinicians, deliver clinical preventive education to patients, implement referral systems, and deliver impressions via media campaigns.


Assuntos
Prestação Integrada de Cuidados de Saúde/organização & administração , Assistência Odontológica , Cárie Dentária/prevenção & controle , Acesso aos Serviços de Saúde/estatística & dados numéricos , Saúde Bucal , Doença Crônica , Humanos , Projetos Piloto , Encaminhamento e Consulta , Estados Unidos
10.
J Med Chem ; 64(9): 5470-5484, 2021 05 13.
Artigo em Inglês | MEDLINE | ID: mdl-33852312

RESUMO

The Th17 pathway has been implicated in autoimmune diseases. The retinoic acid receptor-related orphan receptor C2 (RORγt) is a master regulator of Th17 cells and controls the expression of IL-17A. RORγt is expressed primarily in IL-17A-producing lymphoid cells. Here we describe a virtual screen of the ligand-binding pocket and subsequent screen in a binding assay that identified the 1-benzyl-4',5'-dihydrospiro[piperidine-4,7'-thieno[2,3-c]pyran]-2'-carboxamide scaffold as a starting point for optimization of binding affinity and functional activity guided by structure-based design. Compound 12 demonstrated activity in a mouse PK/PD model and efficacy in an inflammatory arthritis mouse model that were used to define the level and duration of target engagement required for efficacy in vivo. Further optimization to improve ADME and physicochemical properties with guidance from simulations and modeling provided compound 22, which is projected to achieve the level and duration of target engagement required for efficacy in the clinic.


Assuntos
Ligantes , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/metabolismo , Tiofenos/química , Animais , Artrite/induzido quimicamente , Artrite/tratamento farmacológico , Artrite/patologia , Sítios de Ligação , Cristalografia por Raios X , Modelos Animais de Doenças , Desenho de Fármacos , Feminino , Meia-Vida , Humanos , Interleucina-17/genética , Interleucina-17/metabolismo , Leucócitos Mononucleares/citologia , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/metabolismo , Camundongos , Simulação de Dinâmica Molecular , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/química , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/genética , Ligação Proteica , Relação Estrutura-Atividade , Tiofenos/metabolismo , Tiofenos/farmacologia , Tiofenos/uso terapêutico
11.
Prev Chronic Dis ; 18: E40, 2021 04 29.
Artigo em Inglês | MEDLINE | ID: mdl-33914679

RESUMO

In this study, we used data from the Behavioral Risk Factor Surveillance System to conduct multivariable analyses to examine whether having selected chronic diseases was associated with lower past-year dental service utilization among US adults aged 50 years or older. We found consistent lower dental service utilization among older adults with diabetes, heart disease or stroke, and chronic obstructive pulmonary disease (COPD) compared with those without the disease after adjusting for sociodemographic characteristics. We also found lower dental service utilization among older adults with lower income, less education, and no health care coverage and among those who smoked. Effective interventions are needed to reduce disparities in access to dental care among at-risk and vulnerable populations.


Assuntos
Renda , Idoso , Sistema de Vigilância de Fator de Risco Comportamental , Doença Crônica , Escolaridade , Humanos , Prevalência , Estados Unidos/epidemiologia
12.
bioRxiv ; 2021 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-33564763

RESUMO

Recently approved vaccines have already shown remarkable protection in limiting SARS-CoV-2 associated disease. However, immunologic mechanism(s) of protection, as well as how boosting alters immunity to wildtype and newly emerging strains, remain incompletely understood. Here we deeply profiled the humoral immune response in a cohort of non-human primates immunized with a stable recombinant full-length SARS-CoV-2 spike (S) glycoprotein (NVX-CoV2373) at two dose levels, administered as a single or two-dose regimen with a saponin-based adjuvant Matrix-M™. While antigen dose had some effect on Fc-effector profiles, both antigen dose and boosting significantly altered overall titers, neutralization and Fc-effector profiles, driving unique vaccine-induced antibody fingerprints. Combined differences in antibody effector functions and neutralization were strongly associated with distinct levels of protection in the upper and lower respiratory tract, pointing to the presence of combined, but distinct, compartment-specific neutralization and Fc-mechanisms as key determinants of protective immunity against infection. Moreover, NVX-CoV2373 elicited antibodies functionally target emerging SARS-CoV-2 variants, collectively pointing to the critical collaborative role for Fab and Fc in driving maximal protection against SARS-CoV-2. Collectively, the data presented here suggest that a single dose may prevent disease, but that two doses may be essential to block further transmission of SARS-CoV-2 and emerging variants. HIGHLIGHTS: NVX-CoV2373 subunit vaccine elicits receptor blocking, virus neutralizing antibodies, and Fc-effector functional antibodies.The vaccine protects against respiratory tract infection and virus shedding in non-human primates (NHPs).Both neutralizing and Fc-effector functions contribute to protection, potentially through different mechanisms in the upper and lower respiratory tract.Both macaque and human vaccine-induced antibodies exhibit altered Fc-receptor binding to emerging mutants.

13.
Res Sq ; 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33619473

RESUMO

Recently approved vaccines have already shown remarkable protection in limiting SARS-CoV-2 associated disease. However, immunologic mechanism(s) of protection, as well as how boosting alters immunity to wildtype and newly emerging strains, remain incompletely understood. Here we deeply profiled the humoral immune response in a cohort of non-human primates immunized with a stable recombinant full-length SARS-CoV-2 spike (S) glycoprotein (NVX-CoV2373) at two dose levels, administered as a single or two-dose regimen with a saponin-based adjuvant Matrix-M™. While antigen dose had some effect on Fc-effector profiles, both antigen dose and boosting significantly altered overall titers, neutralization and Fc-effector profiles, driving unique vaccine-induced antibody fingerprints. Combined differences in antibody effector functions and neutralization were strongly associated with distinct levels of protection in the upper and lower respiratory tract, pointing to the presence of combined, but distinct, compartment-specific neutralization and Fc-mechanisms as key determinants of protective immunity against infection. Moreover, NVX-CoV2373 elicited antibodies functionally target emerging SARS-CoV-2 variants, collectively pointing to the critical collaborative role for Fab and Fc in driving maximal protection against SARS-CoV-2. Collectively, the data presented here suggest that a single dose may prevent disease, but that two doses may be essential to block further transmission of SARS-CoV-2 and emerging variants.

14.
Nat Commun ; 12(1): 372, 2021 01 14.
Artigo em Inglês | MEDLINE | ID: mdl-33446655

RESUMO

The COVID-19 pandemic continues to spread throughout the world with an urgent need for a safe and protective vaccine to effectuate herd protection and control the spread of SARS-CoV-2. Here, we report the development of a SARS-CoV-2 subunit vaccine (NVX-CoV2373) from the full-length spike (S) protein that is stable in the prefusion conformation. NVX-CoV2373 S form 27.2-nm nanoparticles that are thermostable and bind with high affinity to the human angiotensin-converting enzyme 2 (hACE2) receptor. In mice, low-dose NVX-CoV2373 with saponin-based Matrix-M adjuvant elicit high titer anti-S IgG that blocks hACE2 receptor binding, neutralize virus, and protects against SARS-CoV-2 challenge with no evidence of vaccine-associated enhanced respiratory disease. NVX-CoV2373 also elicits multifunctional CD4+ and CD8+ T cells, CD4+ follicular helper T cells (Tfh), and antigen-specific germinal center (GC) B cells in the spleen. In baboons, low-dose levels of NVX-CoV2373 with Matrix-M was also highly immunogenic and elicited high titer anti-S antibodies and functional antibodies that block S-protein binding to hACE2 and neutralize virus infection and antigen-specific T cells. These results support the ongoing phase 1/2 clinical evaluation of the safety and immunogenicity of NVX-CoV2373 with Matrix-M (NCT04368988).


Assuntos
Vacinas contra COVID-19/imunologia , COVID-19/prevenção & controle , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Enzima de Conversão de Angiotensina 2/genética , Enzima de Conversão de Angiotensina 2/imunologia , Animais , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , COVID-19/genética , COVID-19/imunologia , COVID-19/virologia , Vacinas contra COVID-19/administração & dosagem , Vacinas contra COVID-19/genética , Modelos Animais de Doenças , Feminino , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Papio , SARS-CoV-2/genética , Glicoproteína da Espícula de Coronavírus/administração & dosagem , Glicoproteína da Espícula de Coronavírus/genética , Linfócitos T/imunologia , Vacinas de Subunidades/administração & dosagem , Vacinas de Subunidades/genética , Vacinas de Subunidades/imunologia
15.
Clin Infect Dis ; 73(11): e4278-e4287, 2021 12 06.
Artigo em Inglês | MEDLINE | ID: mdl-33146720

RESUMO

BACKGROUND: Recurrent reports of suboptimal influenza vaccine effectiveness have renewed calls to develop improved, broadly cross-protective influenza vaccines. Here, we evaluated the safety and immunogenicity of a novel, saponin (Matrix-M)-adjuvanted, recombinant hemagglutinin (HA) quadrivalent nanoparticle influenza vaccine (qNIV). METHODS: We conducted a randomized, observer-blind, comparator-controlled (trivalent high-dose inactivated influenza vaccine [IIV3-HD] or quadrivalent recombinant influenza vaccine [RIV4]), safety and immunogenicity trial of qNIV (5 doses/formulations) in healthy adults ≥65 years. Vaccine immunogenicity was measured by hemagglutination-inhibition assays using reagents that express wild-type hemagglutination inhibition (wt-HAI) sequences and cell-mediated immune responses. RESULTS: A total of 1375 participants were randomized, immunized, and followed for safety and immunogenicity. Matrix-M-adjuvanted qNIV induced superior wt-HAI antibody responses against 5 of 6 homologous or drifted strains compared with unadjuvanted qNIV. Adjuvanted qNIV induced post-vaccination wt-HAI antibody responses at day 28 that were statistically higher than IIV3-HD against a panel of homologous or drifted A/H3N2 strains, similar to IIV3-HD against homologous A/H1N1 and B (Victoria) strains and similar to RIV4 against all homologous and drifted strains evaluated. The qNIV formulation with 75 µg Matrix-M adjuvant induced substantially higher post-vaccination geometric mean fold increases of influenza HA-specific polyfunctional CD4+ T cells compared with IIV3-HD or RIV4. Overall, similar frequencies of solicited and unsolicited adverse events were reported in all treatment groups. CONCLUSIONS: qNIV with 75 µg Matrix-M adjuvant was well tolerated and induced robust antibody and cellular responses, notably against both homologous and drifted A/H3N2 viruses. Further investigation in a pivotal phase 3 trial is underway. CLINICAL TRIALS REGISTRATION: NCT03658629.


Assuntos
Vírus da Influenza A Subtipo H1N1 , Vacinas contra Influenza , Influenza Humana , Nanopartículas , Saponinas , Adulto , Anticorpos Antivirais , Linfócitos T CD4-Positivos , Hemaglutinação , Testes de Inibição da Hemaglutinação , Hemaglutininas , Humanos , Imunogenicidade da Vacina , Vírus da Influenza A Subtipo H3N2 , Influenza Humana/prevenção & controle , Vacinas de Produtos Inativados
16.
Vaccine ; 38(50): 7892-7896, 2020 11 25.
Artigo em Inglês | MEDLINE | ID: mdl-33139139

RESUMO

There is an urgent need for a safe and protective vaccine to control the global spread of SARS-CoV-2 and prevent COVID-19. Here, we report the immunogenicity and protective efficacy of a SARS-CoV-2 subunit vaccine (NVX-CoV2373) produced from the full-length SARS-CoV-2 spike (S) glycoprotein stabilized in the prefusion conformation. Cynomolgus macaques (Macaca fascicularis) immunized with NVX-CoV2373 and the saponin-based Matrix-M™ adjuvant induced anti-S antibody that was neutralizing and blocked binding to the human angiotensin-converting enzyme 2 (hACE2) receptor. Following intranasal and intratracheal challenge with SARS-CoV-2, immunized macaques were protected against upper and lower infection and pulmonary disease. These results support ongoing phase 1/2 clinical studies of the safety and immunogenicity of NVX-CoV2327 vaccine (NCT04368988).


Assuntos
Vacinas contra COVID-19/farmacologia , COVID-19/prevenção & controle , SARS-CoV-2/imunologia , Adjuvantes Imunológicos/farmacologia , Adolescente , Adulto , Idoso , Enzima de Conversão de Angiotensina 2/imunologia , Enzima de Conversão de Angiotensina 2/metabolismo , Animais , Anticorpos Neutralizantes , COVID-19/imunologia , Vacinas contra COVID-19/genética , Vacinas contra COVID-19/imunologia , Chlorocebus aethiops , Feminino , Humanos , Soros Imunes/efeitos dos fármacos , Soros Imunes/imunologia , Macaca fascicularis , Masculino , Pessoa de Meia-Idade , Glicoproteína da Espícula de Coronavírus/genética , Vacinas Sintéticas/imunologia , Vacinas Sintéticas/farmacologia , Células Vero , Carga Viral , Adulto Jovem
17.
Science ; 370(6520): 1089-1094, 2020 11 27.
Artigo em Inglês | MEDLINE | ID: mdl-33082295

RESUMO

Vaccine efforts to combat the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is responsible for the current coronavirus disease 2019 (COVID-19) pandemic, are focused on SARS-CoV-2 spike glycoprotein, the primary target for neutralizing antibodies. We performed cryo-election microscopy and site-specific glycan analysis of one of the leading subunit vaccine candidates from Novavax, which is based on a full-length spike protein formulated in polysorbate 80 detergent. Our studies reveal a stable prefusion conformation of the spike immunogen with slight differences in the S1 subunit compared with published spike ectodomain structures. We also observed interactions between the spike trimers, allowing formation of higher-order spike complexes. This study confirms the structural integrity of the full-length spike protein immunogen and provides a basis for interpreting immune responses to this multivalent nanoparticle immunogen.


Assuntos
Vacinas contra COVID-19/química , Glicoproteína da Espícula de Coronavírus/química , Microscopia Crioeletrônica , Humanos , Domínios Proteicos , Multimerização Proteica
18.
Vaccines (Basel) ; 8(4)2020 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-33066540

RESUMO

Human respiratory syncytial virus (RSV) is a cause of lower respiratory tract infection in infants, young children, and older adults. There is no licensed vaccine and prophylactic treatment options are limited. The RSV fusion (F) glycoprotein is a target of host immunity and thus a focus for vaccine development. F-trimers are metastable and undergo significant rearrangements from the prefusion to a stable postfusion structure with neutralizing epitopes on intermediate structures. We hypothesize that vaccine strategies that recapitulate the breathable F quaternary structure, and provide accessibility of B-cells to epitopes on intermediate conformations, may collectively contribute to protective immunity, while rigid prefusion F structures restrict access to key protective epitopes. To test this hypothesis, we used the near full-length prefusogenic F as a backbone to construct three prefusion F variants with substitutions in the hydrophobic head cavity: (1) disulfide bond mutant (DS), (2) space filling hydrophobic amino acid substitutions (Cav1), and (3) DS, Cav1 double mutant (DS-Cav1). In this study, we compared the immunogenicity of prefusogenic F to prefusion F variants in two animal models. Native prefusogenic F was significantly more immunogenic, producing high titer antibodies to prefusogenic, prefusion, and postfusion F structures, while animals immunized with DS or DS-Cav1 produced antibodies to prefusion F. Importantly, prefusogenic F elicited antibodies that target neutralizing epitopes including prefusion-specific site zero (Ø) and V and conformation-independent neutralizing sites II and IV. Immunization with DS or DS-Cav1 elicited antibodies primarily to prefusion-specific sites Ø and V with little or no antibodies to other key neutralizing sites. Animals immunized with prefusogenic F also had significantly higher levels of antibodies that cross-neutralized RSV A and B subtypes, while immunization with DS or DS-Cav1 produced antibodies primarily to the A subtype. We conclude that breathable trimeric vaccines that closely mimic the native F-structure, and incorporate strategies for B-cell accessibility to protective epitopes, are important considerations for vaccine design. F structures locked in a single conformation restrict access to neutralizing epitopes that may collectively contribute to destabilizing F-trimers important for broad protection. These results also have implications for vaccine strategies targeting other type 1 integral membrane proteins.

19.
N Engl J Med ; 383(24): 2320-2332, 2020 12 10.
Artigo em Inglês | MEDLINE | ID: mdl-32877576

RESUMO

BACKGROUND: NVX-CoV2373 is a recombinant severe acute respiratory syndrome coronavirus 2 (rSARS-CoV-2) nanoparticle vaccine composed of trimeric full-length SARS-CoV-2 spike glycoproteins and Matrix-M1 adjuvant. METHODS: We initiated a randomized, placebo-controlled, phase 1-2 trial to evaluate the safety and immunogenicity of the rSARS-CoV-2 vaccine (in 5-µg and 25-µg doses, with or without Matrix-M1 adjuvant, and with observers unaware of trial-group assignments) in 131 healthy adults. In phase 1, vaccination comprised two intramuscular injections, 21 days apart. The primary outcomes were reactogenicity; laboratory values (serum chemistry and hematology), according to Food and Drug Administration toxicity scoring, to assess safety; and IgG anti-spike protein response (in enzyme-linked immunosorbent assay [ELISA] units). Secondary outcomes included unsolicited adverse events, wild-type virus neutralization (microneutralization assay), and T-cell responses (cytokine staining). IgG and microneutralization assay results were compared with 32 (IgG) and 29 (neutralization) convalescent serum samples from patients with Covid-19, most of whom were symptomatic. We performed a primary analysis at day 35. RESULTS: After randomization, 83 participants were assigned to receive the vaccine with adjuvant and 25 without adjuvant, and 23 participants were assigned to receive placebo. No serious adverse events were noted. Reactogenicity was absent or mild in the majority of participants, more common with adjuvant, and of short duration (mean, ≤2 days). One participant had mild fever that lasted 1 day. Unsolicited adverse events were mild in most participants; there were no severe adverse events. The addition of adjuvant resulted in enhanced immune responses, was antigen dose-sparing, and induced a T helper 1 (Th1) response. The two-dose 5-µg adjuvanted regimen induced geometric mean anti-spike IgG (63,160 ELISA units) and neutralization (3906) responses that exceeded geometric mean responses in convalescent serum from mostly symptomatic Covid-19 patients (8344 and 983, respectively). CONCLUSIONS: At 35 days, NVX-CoV2373 appeared to be safe, and it elicited immune responses that exceeded levels in Covid-19 convalescent serum. The Matrix-M1 adjuvant induced CD4+ T-cell responses that were biased toward a Th1 phenotype. (Funded by the Coalition for Epidemic Preparedness Innovations; ClinicalTrials.gov number, NCT04368988).


Assuntos
Vacinas contra COVID-19/imunologia , COVID-19/prevenção & controle , Glicoproteína da Espícula de Coronavírus/imunologia , Adjuvantes Imunológicos/administração & dosagem , Adolescente , Adulto , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Vacinas contra COVID-19/efeitos adversos , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Esquemas de Imunização , Imunogenicidade da Vacina , Imunoglobulina G/imunologia , Masculino , Pessoa de Meia-Idade , Nanopartículas , Pandemias , Saponinas , Células Th1/imunologia , Vacinas Sintéticas/efeitos adversos , Vacinas Sintéticas/imunologia , Adulto Jovem
20.
bioRxiv ; 2020 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-32793901

RESUMO

Vaccine efforts against the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) responsible for the current COVID-19 pandemic are focused on SARS-CoV-2 spike glycoprotein, the primary target for neutralizing antibodies. Here, we performed cryo-EM and site-specific glycan analysis of one of the leading subunit vaccine candidates from Novavax based on a full-length spike protein formulated in polysorbate 80 (PS 80) detergent. Our studies reveal a stable prefusion conformation of the spike immunogen with slight differences in the S1 subunit compared to published spike ectodomain structures. Interestingly, we also observed novel interactions between the spike trimers allowing formation of higher order spike complexes. This study confirms the structural integrity of the full-length spike protein immunogen and provides a basis for interpreting immune responses to this multivalent nanoparticle immunogen.

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