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1.
Pediatr Allergy Immunol ; 35(5): e14161, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38796784

RESUMO

BACKGROUND: Treatment with anti-CD20 antibodies (rituximab) is used in both adults and children to treat various autoimmune and oncological diseases. Rituximab depletes B CD20+ cells and, thereby, antibody response to vaccines. This study aimed to examine the antibody response to mRNA-based COVID-19 vaccines in children aged 5-18 years undergoing rituximab treatment compared to healthy matched children. METHODS: Between 31 January and 18 July 2022, we conducted a prospective observational study at the Geneva University Hospitals, enrolling children aged 5-18 years under rituximab treatment who had received two mRNA-based SARS-CoV-2 vaccine doses. Controls were healthy volunteers with no significant medical conditions. Exclusion criteria included a recent SARS-CoV-2 infection. Blood samples were collected at day 60 (±30) and day 270 (±90) after the second vaccination. RESULTS: The rituximab-treated group exhibited significantly lower levels of antibodies specific to the anti-receptor binding domain (RBD) of the SARS-CoV-2 spike (S) protein than healthy controls at 60 (±30) days after the second vaccine dose (geometric mean concentration: 868.3 IU/mL in patients and 11,393 IU/mL in controls; p = .008). However, patients with a rituximab-to-vaccine interval shorter than 6 months and with evidence of a past infection (based on positive anti-N antibody levels) had a high level of anti-RBD antibodies. CONCLUSION: A past infection with SARS-CoV-2 may induce anti-RBD-specific memory B cells that can be re-activated by SARS-CoV-2 vaccination, even after rituximab-induced B-cell depletion. This suggests that it is possible to vaccinate earlier than 6 months after rituximab to develop a good antibody response, especially in the case of past SARS-CoV-2 infection.


Assuntos
Anticorpos Antivirais , Vacinas contra COVID-19 , COVID-19 , Rituximab , SARS-CoV-2 , Humanos , Rituximab/uso terapêutico , Criança , COVID-19/imunologia , COVID-19/prevenção & controle , SARS-CoV-2/imunologia , Feminino , Masculino , Adolescente , Pré-Escolar , Estudos Prospectivos , Anticorpos Antivirais/sangue , Vacinas contra COVID-19/imunologia , Imunogenicidade da Vacina , Glicoproteína da Espícula de Coronavírus/imunologia
2.
Rev Med Suisse ; 20(869): 744-747, 2024 Apr 10.
Artigo em Francês | MEDLINE | ID: mdl-38616685

RESUMO

The number of elderly people is constantly increasing in Switzerland. This population is often at higher risk of infections and concomitant decompensation of underlying comorbidities, in particular cardiac or respiratory diseases. Vaccines are some of the most effective preventive measures for limiting morbidity and mortality related to some of those infections, such as influenza or shingles. In order to improve vaccination coverage, it is essential to inform the patients of the benefits of vaccination, and to plan a catch-up vaccination consultation. The goal of this article is to offer a practical guide for the general practitioner detailing vaccines for the elderly recommended in Switzerland.


Le nombre de personnes âgées est en constante augmentation en Suisse. Celles-ci sont souvent plus à risque de présenter des infections et de façon concomitante une décompensation de leurs comorbidités, notamment cardiaques et respiratoires. La vaccination est l'une des mesures préventives efficaces pour limiter la morbimortalité associée à certaines de ces infections, comme la grippe ou le zona. Afin d'améliorer la couverture vaccinale, il est primordial d'informer les patients sur les bénéfices de la vaccination et de prévoir une consultation dédiée à une mise à jour vaccinale. Le but de cet article est d'offrir un guide pratique pour le médecin de famille sur les différents vaccins recommandés chez la personne âgée.


Assuntos
Clínicos Gerais , Vacinas contra Influenza , Influenza Humana , Idoso , Humanos , Vacinação , Coração , Influenza Humana/epidemiologia , Influenza Humana/prevenção & controle
3.
Hum Vaccin Immunother ; 20(1): 2292376, 2024 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-38191151

RESUMO

Patients on dialysis (PoD) are at high risk of severe morbidity and mortality from COVID-19. Characterizing long-term vaccine immune responses in these patients will help optimize vaccine schedule for PoD. This study aimed to determine whether long-term humoral and B and T cell-responses post 3rd and 4th dose of the BNT162b2 vaccine differed between PoD and controls. Non-infected PoD and controls vaccinated with BNT162b2 were recruited in Ziv Medical Center, Israel, between 2021 and 2022. Specimens were collected 1-2 months pre 3rd dose; 1-3 months post 3rd dose; 4-5 months post 3rd dose and 3-5 months post the 4th dose. Anti-SARS-CoV-2 spike (spike) specific antibodies, spike specific memory B cells, and spike specific CD154+ T cells as well as cytokines producing CD4+/CD8+ T cells were measured using standardized assays and compared between PoD and controls at each time point using Mann Whitney and Fisher's exact tests. We recruited 22 PoD and 20 controls. Antibody levels in PoD were lower compared to controls pre 3rd dose but not post 3rd and 4th doses. Frequencies of spike specific memory B cell populations were similar between PoD and controls overall. Frequencies of spike specific T cells, including those producing IFNγ and TNFα, were not lower in PoD. B and T cell mediated immune response in PoD following a 3rd and a 4th dose of the BNT162b2 vaccine was not inferior to controls up to 5 months post vaccination. Our results suggest that standard BNT162b2 vaccination is suitable for this group.


Assuntos
Diálise Renal , Vacinas , Humanos , Vacina BNT162 , Linfócitos T , Vacinação
4.
Front Immunol ; 14: 1107156, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37006315

RESUMO

Objectives: To comprehensively analyze the quality of the antibody response between children with Multisystem inflammatory syndrome (MIS-C) and age-matched controls at one month after SARS-CoV-2 exposure, and infected in the same time-period. Methods: Serum from 20 MIS-C children at admission, and 14 control children were analyzed. Antigen specific antibody isotypes and subclasses directed against various antigens of SARS-CoV-2 as well as against human common coronavirus (HCoVs) and commensal or pathogenic microorganisms were assessed by a bead-based multiplexed serological assay and by ELISA. The functionality of these antibodies was also assessed using a plaque reduction neutralization test, a RBD-specific avidity assay, a complement deposition assay and an antibody-dependent neutrophil phagocytosis (ADNP) assay. Results: Children with MIS-C developed a stronger IgA antibody response in comparison to children with uncomplicated COVID-19, while IgG and IgM responses are largely similar in both groups. We found a typical class-switched antibody profile with high level of IgG and IgA titers and a measurable low IgM due to relatively recent SARS-CoV-2 infection (one month). SARS-CoV-2-specific IgG antibodies of MIS-C children had higher functional properties (higher neutralization activity, avidity and complement binding) as compared to children with uncomplicated COVID-19. There was no difference in the response to common endemic coronaviruses between both groups. However, MIS-C children had a moderate increase against mucosal commensal and pathogenic strains, reflecting a potential association between a disruption of the mucosal barrier with the disease. Conclusion: Even if it is still unclear why some children develop a MIS-C, we show here that MIS-C children produce higher titers of IgA antibodies, and IgG antibodies with higher functionality, which could reflect the local gastro-intestinal mucosal inflammation potentially induced by a sustained SARS-CoV-2 gut infection leading to continuous release of SARS-CoV-2 antigens.


Assuntos
Antígenos de Grupos Sanguíneos , COVID-19 , Doenças do Tecido Conjuntivo , Humanos , Criança , SARS-CoV-2 , Formação de Anticorpos , Anticorpos Antivirais , Imunoglobulina A , Imunoglobulina G , Imunoglobulina M
5.
Nat Biomed Eng ; 7(7): 943-958, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37012313

RESUMO

Methods for the analysis of cell secretions at the single-cell level only provide semiquantitative endpoint readouts. Here we describe a microwell array for the real-time spatiotemporal monitoring of extracellular secretions from hundreds of single cells in parallel. The microwell array incorporates a gold substrate with arrays of nanometric holes functionalized with receptors for a specific analyte, and is illuminated with light spectrally overlapping with the device's spectrum of extraordinary optical transmission. Spectral shifts in surface plasmon resonance resulting from analyte-receptor bindings around a secreting cell are recorded by a camera as variations in the intensity of the transmitted light while machine-learning-assisted cell tracking eliminates the influence of cell movements. We used the microwell array to characterize the antibody-secretion profiles of hybridoma cells and of a rare subset of antibody-secreting cells sorted from human donor peripheral blood mononuclear cells. High-throughput measurements of spatiotemporal secretory profiles at the single-cell level will aid the study of the physiological mechanisms governing protein secretion.


Assuntos
Leucócitos Mononucleares , Humanos , Hibridomas
6.
Clin Infect Dis ; 77(4): 645-648, 2023 08 22.
Artigo em Inglês | MEDLINE | ID: mdl-37073575

RESUMO

The timing of maternal pertussis vaccination influences the titers of cord-blood anti-pertussis antibodies. Whether it affects their avidity is unknown. We demonstrate in 298 term and 72 preterm neonates that antibody avidity is independent of the timing of maternal vaccination, whether comparing second with third trimester or intervals before birth.


Assuntos
Anticorpos Antibacterianos , Coqueluche , Recém-Nascido , Gravidez , Feminino , Humanos , Imunidade Materno-Adquirida , Vacinação , Coqueluche/prevenção & controle , Terceiro Trimestre da Gravidez
7.
Nat Commun ; 13(1): 3840, 2022 07 04.
Artigo em Inglês | MEDLINE | ID: mdl-35787633

RESUMO

Emerging SARS-CoV-2 variants raise questions about escape from previous immunity. As the population immunity to SARS-CoV-2 has become more complex due to prior infections with different variants, vaccinations or the combination of both, understanding the antigenic relationship between variants is needed. Here, we have assessed neutralizing capacity of 120 blood specimens from convalescent individuals infected with ancestral SARS-CoV-2, Alpha, Beta, Gamma or Delta, double vaccinated individuals and patients after breakthrough infections with Delta or Omicron-BA.1. Neutralization against seven authentic SARS-CoV-2 isolates (B.1, Alpha, Beta, Gamma, Delta, Zeta and Omicron-BA.1) determined by plaque-reduction neutralization assay allowed us to map the antigenic relationship of SARS-CoV-2 variants. Highest neutralization titers were observed against the homologous variant. Antigenic cartography identified Zeta and Omicron-BA.1 as separate antigenic clusters. Substantial immune escape in vaccinated individuals was detected for Omicron-BA.1 but not Zeta. Combined infection/vaccination derived immunity results in less Omicron-BA.1 immune escape. Last, breakthrough infections with Omicron-BA.1 lead to broadly neutralizing sera.


Assuntos
COVID-19 , SARS-CoV-2 , Anticorpos , COVID-19/prevenção & controle , Humanos , Vacinação
8.
Curr Opin Infect Dis ; 35(4): 312-320, 2022 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-35849521

RESUMO

PURPOSE OF REVIEW: Hematopoietic stem-cell (HSCT) and solid organ transplant (SOT) recipients are particularly at risk to develop herpes zoster and its complications. A recently approved nonlive, adjuvanted recombinant zoster vaccine (aRZV) is a potential candidate to provide durable prevention of herpes zoster. This review summarizes current scientific evidence and expert recommendations for its use in these populations and offers practical clinical guidance. RECENT FINDINGS: Recent clinical trials have shown aRZV to be well tolerated and efficacious in the prevention of herpes zoster, even in the elderly. Data are emerging that this vaccine might also be effective in immunocompromised individuals, such as SOT and HSCT recipients. Evidence is sparse regarding optimal timing of vaccination and durability of responses. However, several specialized societies have already established expert-based aRZV immunization recommendations for these vulnerable populations. SUMMARY: Practical considerations, safety concerns, and timing of vaccine administration vary from one immunocompromised subpopulation to another. Initial studies show that aRZV has a favorable safety and immunogenicity profile in SOT and HSCT recipients. However, data are sparse, particularly in allogeneic HSCT, and practical recommendations are mostly based on expert opinion. Additional research is needed to offer better insight on aRZV administration in immunocompromised patients.


Assuntos
Transplante de Células-Tronco Hematopoéticas , Vacina contra Herpes Zoster , Herpes Zoster , Transplante de Órgãos , Adjuvantes Imunológicos , Idoso , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Herpes Zoster/prevenção & controle , Vacina contra Herpes Zoster/efeitos adversos , Herpesvirus Humano 3 , Humanos , Transplante de Órgãos/efeitos adversos , Transplantados , Vacinas Sintéticas/efeitos adversos
9.
J Hepatol ; 77(4): 1161-1197, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35868584

RESUMO

The COVID-19 pandemic has presented a serious challenge to the hepatology community, particularly healthcare professionals and patients. While the rapid development of safe and effective vaccines and treatments has improved the clinical landscape, the emergence of the omicron variant has presented new challenges. Thus, it is timely that the European Association for the Study of the Liver provides a summary of the latest data on the impact of COVID-19 on the liver and issues guidance on the care of patients with chronic liver disease, hepatobiliary cancer, and previous liver transplantation, as the world continues to deal with the consequences of the COVID-19 pandemic.


Assuntos
COVID-19 , Hepatopatias , Transplante de Fígado , Neoplasias , Humanos , Hepatopatias/epidemiologia , Hepatopatias/cirurgia , Pandemias , SARS-CoV-2
10.
iScience ; 25(6): 104384, 2022 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-35620424

RESUMO

Monocytes are known to play a critical role in dengue pathophysiology. However, which monocyte subset expresses what inflammatory mediator(s) and what transcriptional features distinguish each of the monocyte subset in vivo remain poorly understood. In this study we provide a detailed transcriptional analysis of the three human monocyte subsets in healthy children and in children with dengue febrile illness. Notably, we found that the CD14+ CD16high intermediate monocyte subset from dengue patients highly upregulated key genes involved in mediating inflammation, endothelial dysfunction, vascular permeability, tissue extravasation, and clot prevention compared to healthy children. The CD14+CD16low classical monocytes shared some of these features. These two subsets increased massively in patients with severe dengue. By contrast, the CD14-CD16high nonclassical monocyte subset upregulated key genes involved in vasoconstriction, endothelial barrier stability, and are involved in endothelial patrolling while showing a significant decline from circulation. These findings improve our understanding of monocyte responses in dengue.

11.
Eur J Clin Invest ; 52(10): e13818, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35598178

RESUMO

BACKGROUND: SARS-CoV-2 infection triggers different auto-antibodies, including anti-apolipoprotein A-1 IgGs (AAA1), which could be of concern as mediators of persistent symptoms. We determined the kinetics of AAA1 response over after COVID-19 and the impact of AAA1 on the inflammatory response and symptoms persistence. METHODS: All serologies were assessed at one, three, six and twelve months in 193 hospital employees with COVID-19. ROC curve analyses and logistic regression models (LRM) were used to determine the prognostic accuracy of AAA1 and their association with patient-reported COVID-19 symptoms persistence at 12 months. Interferon (IFN)-α and-γ production by AAA1-stimulated human monocyte-derived macrophages (HMDM) was assessed in vitro. RESULTS: AAA1 seropositivity was 93% at one month and declined to 15% at 12 months after COVID-19. Persistent symptoms at 12 months were observed in 45.1% of participants, with a predominance of neurological (28.5%), followed by general (15%) and respiratory symptoms (9.3%). Over time, strength of correlations between AAA1 and anti-SARS-COV2 serologies decreased, but remained significant. From the 3rd month on, AAA1 levels predicted persistent respiratory symptoms (area under the curves 0.72-0.74; p < 0.001), independently of disease severity, age and gender (adjusted odds ratios 4.81-4.94; p = 0.02), while anti-SARS-CoV-2 serologies did not. AAA1 increased IFN-α production by HMDMs (p = 0.03), without affecting the IFN-γ response. CONCLUSION: COVID-19 induces a marked though transient AAA1 response, independently predicting one-year persistence of respiratory symptoms. By increasing IFN-α response, AAA1 may contribute to persistent symptoms. If and how AAA1 levels assessment could be of use for COVID-19 risk stratification remains to be determined.


Assuntos
COVID-19 , Anticorpos Antivirais , Antivirais , Apolipoproteína A-I , Autoanticorpos , Humanos , SARS-CoV-2
12.
Front Immunol ; 13: 841009, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35585978

RESUMO

Objective: To comprehensively evaluate SARS-CoV-2 specific B-cell and antibody responses up to one year after mild COVID-19. Methods: In 31 mildly symptomatic COVID-19 participants SARS-CoV-2-specific plasmablasts and antigen-specific memory B cells were measured by ELISpot. Binding antibodies directed against the proteins spike (S), domain S1, and nucleocapsid (N) were estimated using rIFA, ELISA, and commercially available assays, and avidity measured using thiocyanate washout. Neutralizing antibodies against variants of concern were measured using a surrogate-neutralization test. Results: Plasmablast responses were assessed in all participants who gave sequential samples during the first two weeks after infection; they preceded the rise in antibodies and correlated with antibody titers measured at one month. S1 and N protein-specific IgG memory B-cell responses remained stable during the first year, whereas S1-specific IgA memory B-cell responses declined after 6 months. Antibody titers waned over time, whilst potent affinity maturation was observed for anti-RBD antibodies. Neutralizing antibodies against wild-type (WT) and variants decayed during the first 6 months but titers significantly increased for Alpha, Gamma and Delta between 6 months and one year. Therefore, near-similar titers were observed for WT and Alpha after one year, and only slightly lower antibody levels for the Delta variant compared to WT. Anti-RBD antibody responses correlated with the neutralizing antibody titers at all time points, however the predicted titers were 3-fold lower at one year compared to one month. Conclusion: In mild COVID-19, stable levels of SARS-CoV-2 specific memory B cells and antibodies neutralizing current variants of concern are observed up to one year post infection. Care should be taken when predicting neutralizing titers using commercial assays that measure binding antibodies.


Assuntos
COVID-19 , SARS-CoV-2 , Anticorpos Neutralizantes , Anticorpos Antivirais , Humanos , Glicoproteína da Espícula de Coronavírus
14.
JAMA Neurol ; 79(4): 399-404, 2022 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-35212717

RESUMO

IMPORTANCE: The SARS-CoV-2 variant B.1.1.529 (Omicron) escapes neutralizing antibodies elicited after COVID-19 vaccination, while T-cell responses might be better conserved. It is crucial to assess how a third vaccination modifies these responses, particularly for immunocompromised patients with readily impaired antibody responses. OBJECTIVE: To determine T-cell responses to the Omicron spike protein in anti-CD20-treated patients with multiple sclerosis (MS) before and after a third messenger RNA COVID-19 vaccination. DESIGN, SETTING, AND PARTICIPANTS: In this prospective cohort study conducted from March 2021 to November 2021 at the University Hospital Geneva, adults with MS receiving anti-CD20 treatment (ocrelizumab) were identified by their treating neurologists and enrolled in the study. A total of 20 patients received their third dose of messenger RNA COVID-19 vaccine and were included in this analysis. INTERVENTIONS: Blood sampling before and 1 month after the third vaccine dose. MAIN OUTCOMES AND MEASURES: Quantification of CD4 and CD8 (cytotoxic) T cells specific for the SARS-CoV-2 spike proteins of the vaccine strain as well as the Delta and Omicron variants, comparing frequencies before and after the third vaccine dose. RESULTS: Of 20 included patients, 11 (55%) were male, and the median (IQR) age was 45.8 (37.8-53.3) years. Spike-specific CD4 and CD8 T-cell memory against all variants were maintained in 9 to 12 patients 6 months after their second vaccination, albeit at lower median frequencies against the Delta and Omicron variants compared with the vaccine strain (CD8 T cells: Delta, 83.0%; 95% CI, 73.6-114.5; Omicron, 78.9%; 95% CI, 59.4-100.0; CD4 T cells: Delta, 72.2%; 95% CI, 67.4-90.5; Omicron, 62.5%; 95% CI, 51.0-89.0). A third dose enhanced the number of responders to all variants (11 to 15 patients) and significantly increased CD8 T-cell responses, but the frequencies of Omicron-specific CD8 T cells remained 71.1% (95% CI, 41.6-96.2) of the responses specific to the vaccine strain. CONCLUSIONS AND RELEVANCE: In this cohort study of patients with MS treated with ocrelizumab, there were robust T-cell responses recognizing spike proteins from the Delta and Omicron variants, suggesting that COVID-19 vaccination in patients taking B-cell-depleting drugs may protect them against serious complications from COVID-19 infection. T-cell response rates increased after the third dose, demonstrating the importance of a booster dose for this population.


Assuntos
COVID-19 , Esclerose Múltipla , Adulto , Anticorpos Monoclonais Humanizados , Anticorpos Antivirais , COVID-19/prevenção & controle , Vacinas contra COVID-19 , Estudos de Coortes , Humanos , Masculino , Pessoa de Meia-Idade , Esclerose Múltipla/tratamento farmacológico , Estudos Prospectivos , RNA Mensageiro , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus/uso terapêutico
15.
Rev Med Suisse ; 18(767): 165-168, 2022 Feb 02.
Artigo em Francês | MEDLINE | ID: mdl-35107890

RESUMO

During this global health crisis, COVID-19 unfortunately did not spare pregnant women, who are at greater risk of becoming infected, developing severe forms and having obstetric complications. In this article we will talk about the risks associated with COVID-19 during pregnancy and in particular the existing data on the drugs to be administered in the event of illness and how to avoid infection and its complications through vaccination.


Durant cette crise sanitaire mondiale, le Covid-19 n'a malheureusement pas épargné les femmes enceintes. Celles-ci sont plus à risque d'être infectées, de développer des formes sévères et d'avoir des complications obstétricales. Dans cet article, nous allons parler des risques liés au Covid-19 durant la grossesse et notamment des données existantes sur les médicaments à administrer en cas de maladie et comment éviter l'infection et ses complications grâce à la vaccination.


Assuntos
COVID-19 , Vacinas contra Influenza , Preparações Farmacêuticas , Complicações Infecciosas na Gravidez , Feminino , Humanos , Gravidez , Complicações Infecciosas na Gravidez/prevenção & controle , SARS-CoV-2
16.
Clin Infect Dis ; 75(1): e1037-e1045, 2022 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-34791081

RESUMO

BACKGROUND: Patients treated with anti-CD20 therapy are particularly at risk of developing severe coronavirus disease 2019 (COVID-19); however, little is known regarding COVID-19 vaccine effectiveness in this population. METHODS: This prospective observational cohort study assesses humoral and T-cell responses after vaccination with 2 doses of mRNA-based COVID-19 vaccines in patients treated with rituximab for rheumatic diseases or ocrelizumab for multiple sclerosis (n = 37), compared to immunocompetent individuals (n = 22). RESULTS: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific antibodies were detectable in only 69.4% of patients and at levels that were significantly lower compared to controls who all seroconverted. In contrast to antibodies, Spike (S)-specific CD4 T cells were equally detected in immunocompetent and anti-CD20 treated patients (85-90%) and mostly of a Th1 phenotype. Response rates of S-specific CD8 T cells were higher in ocrelizumab (96.2%) and rituximab-treated patients (81.8%) as compared to controls (66.7%). S-specific CD4 and CD8 T cells were polyfunctional but expressed more effector molecules in patients than in controls. During follow-up, 3 MS patients without SARS-CoV-2-specific antibody response had a mild breakthrough infection. One of them had no detectable S-specific T cells after vaccination. CONCLUSIONS: Our study suggests that patients on anti-CD20 treatment are able to mount potent T-cell responses to mRNA COVID-19 vaccines, despite impaired humoral responses. This could play an important role in the reduction of complications of severe COVID-19.


Assuntos
Tratamento Farmacológico da COVID-19 , COVID-19 , Vacinas Virais , Anticorpos Antivirais , COVID-19/prevenção & controle , Vacinas contra COVID-19 , Humanos , Estudos Prospectivos , RNA Mensageiro , Rituximab , SARS-CoV-2 , Vacinação
17.
Nature ; 602(7896): 307-313, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34937050

RESUMO

Emerging variants of concern (VOCs) are driving the COVID-19 pandemic1,2. Experimental assessments of replication and transmission of major VOCs and progenitors are needed to understand the mechanisms of replication and transmission of VOCs3. Here we show that the spike protein (S) from Alpha (also known as B.1.1.7) and Beta (B.1.351) VOCs had a greater affinity towards the human angiotensin-converting enzyme 2 (ACE2) receptor than that of the progenitor variant S(D614G) in vitro. Progenitor variant virus expressing S(D614G) (wt-S614G) and the Alpha variant showed similar replication kinetics in human nasal airway epithelial cultures, whereas the Beta variant was outcompeted by both. In vivo, competition experiments showed a clear fitness advantage of Alpha over wt-S614G in ferrets and two mouse models-the substitutions in S were major drivers of the fitness advantage. In hamsters, which support high viral replication levels, Alpha and wt-S614G showed similar fitness. By contrast, Beta was outcompeted by Alpha and wt-S614G in hamsters and in mice expressing human ACE2. Our study highlights the importance of using multiple models to characterize fitness of VOCs and demonstrates that Alpha is adapted for replication in the upper respiratory tract and shows enhanced transmission in vivo in restrictive models, whereas Beta does not overcome Alpha or wt-S614G in naive animals.


Assuntos
COVID-19/transmissão , COVID-19/virologia , Mutação , SARS-CoV-2/classificação , SARS-CoV-2/fisiologia , Replicação Viral , Substituição de Aminoácidos , Enzima de Conversão de Angiotensina 2/genética , Enzima de Conversão de Angiotensina 2/metabolismo , Animais , Animais de Laboratório/virologia , COVID-19/veterinária , Cricetinae , Modelos Animais de Doenças , Células Epiteliais/virologia , Feminino , Furões/virologia , Humanos , Masculino , Mesocricetus/virologia , Camundongos , Camundongos Transgênicos , SARS-CoV-2/genética , SARS-CoV-2/crescimento & desenvolvimento , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/metabolismo , Virulência/genética
18.
Vaccines (Basel) ; 9(12)2021 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-34960142

RESUMO

The use of immune checkpoint inhibitors (ICI) has substantially increased the overall survival of cancer patients and has revolutionized the therapeutic situation in oncology. However, not all patients and cancer types respond to ICI, or become resistant over time. Combining ICIs with therapeutic cancer vaccines is a promising option as vaccination may help to overcome resistance to immunotherapies while immunotherapies may increase immune responses to the particular cancer vaccine by reinvigorating exhausted T cells. Thus, it would be possible to reprogram a response with appropriate vaccines, using a particular cancer antigen and a corresponding ICI. Target populations include currently untreatable cancer patients or those who receive treatment regimens with high risk of serious side effects. In addition, with the increased use of ICI in clinical practice, questions arise regarding safety and efficacy of administration of conventional vaccines, such as influenza or COVID-19 vaccines, during active ICI treatment. This review discusses the main principles of prophylactic and therapeutic cancer vaccines, the potential impact on combining therapeutic cancer vaccines with ICI, and briefly summarizes the current knowledge of safety and effectiveness of influenza and COVID-19 vaccines in ICI-treated patients.

19.
Cell Rep ; 37(1): 109773, 2021 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-34587479

RESUMO

SARS-CoV-2 infection in children is less severe than it is in adults. We perform a longitudinal analysis of the early innate responses in children and adults with mild infection within household clusters. Children display fewer symptoms than adults do, despite similar initial viral load, and mount a robust anti-viral immune signature typical of the SARS-CoV-2 infection and characterized by early interferon gene responses; increases in cytokines, such as CXCL10 and GM-CSF; and changes in blood cell numbers. When compared with adults, the antiviral response resolves faster (within a week of symptoms), monocytes and dendritic cells are more transiently activated, and genes associated with B cell activation appear earlier in children. Nonetheless, these differences do not have major effects on the quality of SARS-CoV-2-specific antibody responses. Our findings reveal that better early control of inflammation as observed in children may be key for rapidly controlling infection and limiting the disease course.


Assuntos
Anticorpos Antivirais/imunologia , COVID-19/genética , COVID-19/imunologia , Citocinas/metabolismo , Imunidade Inata , SARS-CoV-2/imunologia , Transcriptoma , Imunidade Adaptativa , Adolescente , Adulto , Linfócitos B/metabolismo , COVID-19/virologia , Quimiocina CXCL10/metabolismo , Criança , Pré-Escolar , Fator Estimulador de Colônias de Granulócitos e Macrófagos/metabolismo , Humanos , Lactente , Inflamação/virologia , Interferons/metabolismo , Estudos Longitudinais , Pessoa de Meia-Idade , Monócitos/metabolismo , Análise de Sequência de RNA , Carga Viral , Adulto Jovem
20.
J Clin Immunol ; 41(8): 1723-1732, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34581925

RESUMO

BACKGROUND: SARS-CoV-2 infection leads to high viral loads in the upper respiratory tract that may be determinant in virus dissemination. The extent of intranasal antiviral response in relation to symptoms is unknown. Understanding how local innate responses control virus is key in the development of therapeutic approaches. METHODS: SARS-CoV-2-infected patients were enrolled in an observational study conducted at the Geneva University Hospitals, Switzerland, investigating virological and immunological characteristics. Nasal wash and serum specimens from a subset of patients were collected to measure viral load, IgA specific for the S1 domain of the spike protein, and a cytokine panel at different time points after infection; cytokine levels were analyzed in relation to symptoms. RESULTS: Samples from 13 SARS-CoV-2-infected patients and six controls were analyzed. We found an increase in CXCL10 and IL-6, whose levels remained elevated for up to 3 weeks after symptom onset. SARS-CoV-2 infection also induced CCL2 and GM-CSF, suggesting local recruitment and activation of myeloid cells. Local cytokine levels correlated with viral load but not with serum cytokine levels, nor with specific symptoms, including anosmia. Some patients had S1-specific IgA in the nasal cavity while almost none had IgG. CONCLUSION: The nasal epithelium is an active site of cytokine response against SARS-CoV-2 that can last more than 2 weeks; in this mild COVID-19 cohort, anosmia was not associated with increases in any locally produced cytokines.


Assuntos
COVID-19/imunologia , Citocinas/biossíntese , Inflamação/etiologia , Mucosa Nasal/imunologia , SARS-CoV-2 , Carga Viral , Adulto , Idoso , Anticorpos Antivirais , COVID-19/virologia , Feminino , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , SARS-CoV-2/imunologia
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