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1.
Nat Commun ; 12(1): 776, 2021 02 03.
Artigo em Inglês | MEDLINE | ID: mdl-33536425

RESUMO

The rapid expansion of the COVID-19 pandemic has made the development of a SARS-CoV-2 vaccine a global health and economic priority. Taking advantage of versatility and rapid development, three SARS-CoV-2 mRNA vaccine candidates have entered clinical trials with a two-dose immunization regimen. However, the waning antibody response in convalescent patients after SARS-CoV-2 infection and the emergence of human re-infection have raised widespread concerns about a possible short duration of SARS-CoV-2 vaccine protection. Here, we developed a nucleoside-modified mRNA vaccine in lipid-encapsulated form that encoded the SARS-CoV-2 RBD, termed as mRNA-RBD. A single immunization of mRNA-RBD elicited both robust neutralizing antibody and cellular responses, and conferred a near-complete protection against wild SARS-CoV-2 infection in the lungs of hACE2 transgenic mice. Noticeably, the high levels of neutralizing antibodies in BALB/c mice induced by mRNA-RBD vaccination were maintained for at least 6.5 months and conferred a long-term notable protection for hACE2 transgenic mice against SARS-CoV-2 infection in a sera transfer study. These data demonstrated that a single dose of mRNA-RBD provided long-term protection against SARS-CoV-2 challenge.


Assuntos
/imunologia , /imunologia , /genética , /imunologia , /genética , Animais , Anticorpos Neutralizantes/imunologia , /genética , Linhagem Celular , Feminino , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Pandemias/prevenção & controle , RNA Mensageiro/genética , RNA Mensageiro/imunologia , RNA Viral/genética , RNA Viral/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Glicoproteína da Espícula de Coronavírus/metabolismo , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/genética , Vacinas Sintéticas/imunologia , Proteínas do Envelope Viral/imunologia
3.
Euro Surveill ; 26(6)2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33573712

RESUMO

The BNT162b2 mRNA COVID-19 vaccine showed high efficacy in clinical trials but observational data from populations not included in trials are needed. We describe immunogenicity 21 days post-dose 1 among 514 Israeli healthcare workers by age, ethnicity, sex and prior COVID-19 infection. Immunogenicity was similar by ethnicity and sex but decreased with age. Those with prior infection had antibody titres one magnitude order higher than naïve individuals regardless of the presence of detectable IgG antibodies pre-vaccination.


Assuntos
/imunologia , Imunogenicidade da Vacina , Adulto , Fatores Etários , Idoso , /administração & dosagem , Relação Dose-Resposta Imunológica , Grupos Étnicos/estatística & dados numéricos , Feminino , Pessoal de Saúde/estatística & dados numéricos , Humanos , Israel/epidemiologia , Masculino , Pessoa de Meia-Idade , Fatores Sexuais , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/imunologia
5.
Adv Drug Deliv Rev ; 169: 137-151, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33340620

RESUMO

The novel corona virus termed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread throughout the globe at a formidable speed, causing tens of millions of cases and more than one million deaths in less than a year of its report in December 2019. Since then, companies and research institutions have raced to develop SARS-CoV-2 vaccines, ranging from conventional viral and protein-based vaccines to those that are more cutting edge, including DNA- and mRNA-based vaccines. Each vaccine exhibits a different potency and duration of efficacy, as determined by the antigen design, adjuvant molecules, vaccine delivery platforms, and immunization method. In this review, we will introduce a few of the leading non-viral vaccines that are under clinical stage development and discuss delivery strategies to improve vaccine efficacy, duration of protection, safety, and mass vaccination.


Assuntos
/administração & dosagem , Sistemas de Liberação de Medicamentos/métodos , Vacinas Sintéticas/administração & dosagem , Animais , /química , Humanos , Vacinas de DNA/administração & dosagem , Vacinas de DNA/química , Vacinas de DNA/genética , Vacinas Sintéticas/química , Vacinas Sintéticas/genética
6.
ACS Nano ; 14(10): 12370-12389, 2020 10 27.
Artigo em Inglês | MEDLINE | ID: mdl-33001626

RESUMO

Despite the vital role of vaccines in fighting viral pathogens, effective vaccines are still unavailable for many infectious diseases. The importance of vaccines cannot be overstated during the outbreak of a pandemic, such as the coronavirus disease 2019 (COVID-19) pandemic. The understanding of genomics, structural biology, and innate/adaptive immunity have expanded the toolkits available for current vaccine development. However, sudden outbreaks and the requirement of population-level immunization still pose great challenges in today's vaccine designs. Well-established vaccine development protocols from previous experiences are in place to guide the pipelines of vaccine development for emerging viral diseases. Nevertheless, vaccine development may follow different paradigms during a pandemic. For example, multiple vaccine candidates must be pushed into clinical trials simultaneously, and manufacturing capability must be scaled up in early stages. Factors from essential features of safety, efficacy, manufacturing, and distributions to administration approaches are taken into consideration based on advances in materials science and engineering technologies. In this review, we present recent advances in vaccine development by focusing on vaccine discovery, formulation, and delivery devices enabled by alternative administration approaches. We hope to shed light on developing better solutions for faster and better vaccine development strategies through the use of biomaterials, biomolecular engineering, nanotechnology, and microfabrication techniques.


Assuntos
Vacinas Virais/imunologia , Ensaios Clínicos como Assunto , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/prevenção & controle , Humanos , Imunogenicidade da Vacina , Potência de Vacina , Vacinas de Subunidades/administração & dosagem , Vacinas de Subunidades/efeitos adversos , Vacinas de Subunidades/imunologia , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/efeitos adversos , Vacinas Sintéticas/imunologia , Vacinas Virais/administração & dosagem , Vacinas Virais/efeitos adversos
7.
Science ; 369(6511): 1603-1607, 2020 09 25.
Artigo em Inglês | MEDLINE | ID: mdl-32732280

RESUMO

The ongoing coronavirus disease 2019 (COVID-19) pandemic has prioritized the development of small-animal models for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We adapted a clinical isolate of SARS-CoV-2 by serial passaging in the respiratory tract of aged BALB/c mice. The resulting mouse-adapted strain at passage 6 (called MASCp6) showed increased infectivity in mouse lung and led to interstitial pneumonia and inflammatory responses in both young and aged mice after intranasal inoculation. Deep sequencing revealed a panel of adaptive mutations potentially associated with the increased virulence. In particular, the N501Y mutation is located at the receptor binding domain (RBD) of the spike protein. The protective efficacy of a recombinant RBD vaccine candidate was validated by using this model. Thus, this mouse-adapted strain and associated challenge model should be of value in evaluating vaccines and antivirals against SARS-CoV-2.


Assuntos
Betacoronavirus/imunologia , Infecções por Coronavirus/prevenção & controle , Modelos Animais de Doenças , Camundongos , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Vacinas Virais/imunologia , Administração Intranasal , Animais , Betacoronavirus/genética , Betacoronavirus/patogenicidade , Infecções por Coronavirus/imunologia , Feminino , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Imunogenicidade da Vacina , Pulmão/virologia , Doenças Pulmonares Intersticiais/virologia , Camundongos Endogâmicos BALB C , Camundongos Transgênicos , Mutação , Peptidil Dipeptidase A/genética , Glicoproteína da Espícula de Coronavírus/genética , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/imunologia , Vacinas Virais/administração & dosagem , Virulência/genética
8.
Nat Commun ; 11(1): 4207, 2020 08 21.
Artigo em Inglês | MEDLINE | ID: mdl-32826924

RESUMO

The rapid spread of coronavirus SARS-CoV-2 greatly threatens global public health but no prophylactic vaccine is available. Here, we report the generation of a replication-incompetent recombinant serotype 5 adenovirus, Ad5-S-nb2, carrying a codon-optimized gene encoding Spike protein (S). In mice and rhesus macaques, intramuscular injection with Ad5-S-nb2 elicits systemic S-specific antibody and cell-mediated immune (CMI) responses. Intranasal inoculation elicits both systemic and pulmonary antibody responses but weaker CMI response. At 30 days after a single vaccination with Ad5-S-nb2 either intramuscularly or intranasally, macaques are protected against SARS-CoV-2 challenge. A subsequent challenge reveals that macaques vaccinated with a 10-fold lower vaccine dosage (1 × 1010 viral particles) are also protected, demonstrating the effectiveness of Ad5-S-nb2 and the possibility of offering more vaccine dosages within a shorter timeframe. Thus, Ad5-S-nb2 is a promising candidate vaccine and warrants further clinical evaluation.


Assuntos
Betacoronavirus/imunologia , Infecções por Coronavirus/prevenção & controle , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Vacinas Virais/administração & dosagem , Adenoviridae/genética , Animais , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Infecções por Coronavirus/imunologia , Relação Dose-Resposta Imunológica , Feminino , Células HEK293 , Humanos , Imunidade Celular , Macaca mulatta , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Pneumonia Viral/imunologia , Sistema Respiratório/patologia , Sistema Respiratório/virologia , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/imunologia , Vacinas Sintéticas/administração & dosagem
9.
Cell ; 182(5): 1271-1283.e16, 2020 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-32795413

RESUMO

There is an urgent need for vaccines against coronavirus disease 2019 (COVID-19) because of the ongoing SARS-CoV-2 pandemic. Among all approaches, a messenger RNA (mRNA)-based vaccine has emerged as a rapid and versatile platform to quickly respond to this challenge. Here, we developed a lipid nanoparticle-encapsulated mRNA (mRNA-LNP) encoding the receptor binding domain (RBD) of SARS-CoV-2 as a vaccine candidate (called ARCoV). Intramuscular immunization of ARCoV mRNA-LNP elicited robust neutralizing antibodies against SARS-CoV-2 as well as a Th1-biased cellular response in mice and non-human primates. Two doses of ARCoV immunization in mice conferred complete protection against the challenge of a SARS-CoV-2 mouse-adapted strain. Additionally, ARCoV is manufactured as a liquid formulation and can be stored at room temperature for at least 1 week. ARCoV is currently being evaluated in phase 1 clinical trials.


Assuntos
RNA Mensageiro/genética , RNA Viral/genética , Vacinas Sintéticas/imunologia , Vacinas Virais/imunologia , Animais , Anticorpos Neutralizantes/imunologia , Sítios de Ligação , Chlorocebus aethiops , Infecções por Coronavirus/genética , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/prevenção & controle , Feminino , Células HEK293 , Células HeLa , Humanos , Imunogenicidade da Vacina , Injeções Intramusculares , Macaca fascicularis , Masculino , Camundongos , Camundongos Endogâmicos ICR , Nanopartículas/química , RNA Mensageiro/metabolismo , RNA Viral/metabolismo , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/metabolismo , Células Th1/imunologia , Potência de Vacina , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/genética , Células Vero , Vacinas Virais/administração & dosagem , Vacinas Virais/genética
10.
Vaccine ; 38(35): 5734-5739, 2020 07 31.
Artigo em Inglês | MEDLINE | ID: mdl-32653276

RESUMO

Several protein vaccine candidates are among the COVID-19 vaccines in development. The Brighton Collaboration Viral Vector Vaccines Safety Working Group (V3SWG) has prepared a standardized template to describe the key considerations for the benefit-risk assessment of protein vaccines. This will help key stakeholders to assess potential safety issues and understand the benefit-risk of such a vaccine platform. The structured and standardized assessment provided by the template would also help contribute to improved public acceptance and communication of licensed protein vaccines.


Assuntos
Vacinas Virais/efeitos adversos , Vacinas Virais/imunologia , Antígenos Virais/administração & dosagem , Antígenos Virais/efeitos adversos , Antígenos Virais/imunologia , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/prevenção & controle , Humanos , Segurança do Paciente , Medição de Risco , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/efeitos adversos , Vacinas Sintéticas/imunologia , Proteínas Virais/administração & dosagem , Proteínas Virais/efeitos adversos , Proteínas Virais/imunologia , Vacinas Virais/administração & dosagem
11.
Nat Commun ; 11(1): 3545, 2020 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-32669564

RESUMO

Group A Streptococcus (GAS) infection causes a range of diseases, but vaccine development is hampered by the high number of serotypes. Here, using reverse vaccinology the authors identify SPy_2191 as a cross-protective vaccine candidate. From 18 initially identified surface proteins, only SPy_2191 is conserved, surface-exposed and inhibits both GAS adhesion and invasion. SPy_2191 immunization in mice generates bactericidal antibodies resulting in opsonophagocytic killing of prevalent and invasive GAS serotypes of different geographical regions, including M1 and M49 (India), M3.1 (Israel), M1 (UK) and M1 (USA). Resident splenocytes show higher interferon-γ and tumor necrosis factor-α secretion upon antigen re-stimulation, suggesting activation of cell-mediated immunity. SPy_2191 immunization significantly reduces streptococcal load in the organs and confers ~76-92% protection upon challenge with invasive GAS serotypes. Further, it significantly suppresses GAS pharyngeal colonization in mice mucosal infection model. Our findings suggest that SPy_2191 can act as a universal vaccine candidate against GAS infections.


Assuntos
Proteínas de Bactérias/imunologia , Proteção Cruzada/imunologia , Infecções Estreptocócicas/prevenção & controle , Vacinas Estreptocócicas/imunologia , Streptococcus pyogenes/imunologia , Animais , Aderência Bacteriana/imunologia , Linhagem Celular , Clonagem Molecular , Modelos Animais de Doenças , Feminino , Humanos , Imunogenicidade da Vacina , Camundongos , Testes de Neutralização , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/imunologia , Sorogrupo , Infecções Estreptocócicas/microbiologia , Vacinas Estreptocócicas/administração & dosagem , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/imunologia
12.
Lancet ; 395(10240): 1845-1854, 2020 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-32450106

RESUMO

BACKGROUND: A vaccine to protect against COVID-19 is urgently needed. We aimed to assess the safety, tolerability, and immunogenicity of a recombinant adenovirus type-5 (Ad5) vectored COVID-19 vaccine expressing the spike glycoprotein of a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) strain. METHODS: We did a dose-escalation, single-centre, open-label, non-randomised, phase 1 trial of an Ad5 vectored COVID-19 vaccine in Wuhan, China. Healthy adults aged between 18 and 60 years were sequentially enrolled and allocated to one of three dose groups (5 × 1010, 1 × 1011, and 1·5 × 1011 viral particles) to receive an intramuscular injection of vaccine. The primary outcome was adverse events in the 7 days post-vaccination. Safety was assessed over 28 days post-vaccination. Specific antibodies were measured with ELISA, and the neutralising antibody responses induced by vaccination were detected with SARS-CoV-2 virus neutralisation and pseudovirus neutralisation tests. T-cell responses were assessed by enzyme-linked immunospot and flow-cytometry assays. This study is registered with ClinicalTrials.gov, NCT04313127. FINDINGS: Between March 16 and March 27, 2020, we screened 195 individuals for eligibility. Of them, 108 participants (51% male, 49% female; mean age 36·3 years) were recruited and received the low dose (n=36), middle dose (n=36), or high dose (n=36) of the vaccine. All enrolled participants were included in the analysis. At least one adverse reaction within the first 7 days after the vaccination was reported in 30 (83%) participants in the low dose group, 30 (83%) participants in the middle dose group, and 27 (75%) participants in the high dose group. The most common injection site adverse reaction was pain, which was reported in 58 (54%) vaccine recipients, and the most commonly reported systematic adverse reactions were fever (50 [46%]), fatigue (47 [44%]), headache (42 [39%]), and muscle pain (18 [17%]. Most adverse reactions that were reported in all dose groups were mild or moderate in severity. No serious adverse event was noted within 28 days post-vaccination. ELISA antibodies and neutralising antibodies increased significantly at day 14, and peaked 28 days post-vaccination. Specific T-cell response peaked at day 14 post-vaccination. INTERPRETATION: The Ad5 vectored COVID-19 vaccine is tolerable and immunogenic at 28 days post-vaccination. Humoral responses against SARS-CoV-2 peaked at day 28 post-vaccination in healthy adults, and rapid specific T-cell responses were noted from day 14 post-vaccination. Our findings suggest that the Ad5 vectored COVID-19 vaccine warrants further investigation. FUNDING: National Key R&D Program of China, National Science and Technology Major Project, and CanSino Biologics.


Assuntos
Infecções por Coronavirus/prevenção & controle , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Vacinas Virais/administração & dosagem , Adenoviridae , Adolescente , Adulto , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Betacoronavirus , China , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Imunidade Celular , Imunidade Humoral , Injeções Intramusculares , Masculino , Pessoa de Meia-Idade , Linfócitos T/imunologia , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/efeitos adversos , Vacinas Sintéticas/uso terapêutico , Vacinas Virais/efeitos adversos , Vacinas Virais/uso terapêutico , Adulto Jovem
13.
Nat Commun ; 11(1): 1985, 2020 04 24.
Artigo em Inglês | MEDLINE | ID: mdl-32332752

RESUMO

The unsatisfactory response rate of immune checkpoint blockade (ICB) immunotherapy severely limits its clinical application as a tumor therapy. Here, we generate a vaccine-based nanosystem by integrating siRNA for Cd274 into the commercial human papillomavirus (HPV) L1 (HPV16 L1) protein. This nanosystem has good biosafety and enhances the therapeutic response rate of anti-tumor immunotherapy. The HPV16 L1 protein activates innate immunity through the type I interferon pathway and exhibits an efficient anti-cancer effect when cooperating with ICB therapy. For both resectable and unresectable breast tumors, the nanosystem decreases 71% tumor recurrence and extends progression-free survival by 67%. Most importantly, the nanosystem successfully induces high response rates in various genetically modified breast cancer models with different antigen loads. The strong immune stimulation elicited by this vaccine-based nanosystem might constitute an approach to significantly improve current ICB immunotherapy.


Assuntos
Antineoplásicos Imunológicos/uso terapêutico , Neoplasias da Mama/terapia , Vacinas Anticâncer/administração & dosagem , Imunoterapia/métodos , Nanopartículas/administração & dosagem , Animais , Antígeno B7-H1/antagonistas & inibidores , Antígeno B7-H1/genética , Neoplasias da Mama/genética , Neoplasias da Mama/imunologia , Vacinas Anticâncer/genética , Vacinas Anticâncer/imunologia , Proteínas do Capsídeo/genética , Proteínas do Capsídeo/imunologia , Linhagem Celular Tumoral/transplante , Modelos Animais de Doenças , Feminino , Técnicas de Silenciamento de Genes , Células HEK293 , Papillomavirus Humano 16/genética , Papillomavirus Humano 16/imunologia , Humanos , Imunidade Inata/genética , Camundongos , Recidiva Local de Neoplasia , Proteínas Oncogênicas Virais/genética , Proteínas Oncogênicas Virais/imunologia , Intervalo Livre de Progressão , RNA Interferente Pequeno/genética , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/genética , Microambiente Tumoral/genética , Microambiente Tumoral/imunologia , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/genética , Vacinas Sintéticas/imunologia
14.
PLoS One ; 15(4): e0230711, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32240193

RESUMO

Vaccinia virus (VACV) has been used extensively as the vaccine against smallpox and as a viral vector for the development of recombinant vaccines and cancer therapies. Replication-competent, non-attenuated VACVs induce strong, long-lived humoral and cell-mediated immune responses and can be effective oncolytic vectors. However, complications from uncontrolled VACV replication in vaccinees and their close contacts can be severe, particularly in individuals with predisposing conditions. In an effort to develop replication-competent VACV vectors with improved safety, we placed VACV late genes encoding core or virion morphogenesis proteins under the control of tet operon elements to regulate their expression with tetracycline antibiotics. These replication-inducible VACVs would only express the selected genes in the presence of tetracyclines. VACVs inducibly expressing the A3L or A6L genes replicated indistinguishably from wild-type VACV in the presence of tetracyclines, whereas there was no evidence of replication in the absence of antibiotics. These outcomes were reflected in mice, where the VACV inducibly expressing the A6L gene caused weight loss and mortality equivalent to wild-type VACV in the presence of tetracyclines. In the absence of tetracyclines, mice were protected from weight loss and mortality, and viral replication was not detected. These findings indicate that replication-inducible VACVs based on the conditional expression of the A3L or A6L genes can be used for the development of safer, next-generation live VACV vectors and vaccines. The design allows for administration of replication-inducible VACV in the absence of tetracyclines (as a replication-defective vector) or in the presence of tetracyclines (as a replication-competent vector) with enhanced safety.


Assuntos
Vetores Genéticos/administração & dosagem , Tetraciclinas/farmacologia , Vírus Vaccinia/crescimento & desenvolvimento , Vaccinia/prevenção & controle , Vírion/crescimento & desenvolvimento , Replicação Viral , Animais , Feminino , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Vacinas Sintéticas/administração & dosagem , Vaccinia/genética , Vaccinia/virologia , Vírus Vaccinia/efeitos dos fármacos , Vírus Vaccinia/genética , Proteínas Virais/genética , Vírion/efeitos dos fármacos
15.
PLoS Negl Trop Dis ; 14(4): e0007717, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32302312

RESUMO

BACKGROUND: The long term and complex nature of Chagas disease in humans has restricted studies on vaccine feasibility. Animal models also have limitations due to technical difficulties in monitoring the extremely low parasite burden that is characteristic of chronic stage infections. Advances in imaging technology offer alternative approaches that circumvent these problems. Here, we describe the use of highly sensitive whole body in vivo imaging to assess the efficacy of recombinant viral vector vaccines and benznidazole-cured infections to protect mice from challenge with Trypanosoma cruzi. METHODOLOGY/PRINCIPAL FINDINGS: Mice were infected with T. cruzi strains modified to express a red-shifted luciferase reporter. Using bioluminescence imaging, we assessed the degree of immunity to re-infection conferred after benznidazole-cure. Those infected for 14 days or more, prior to the onset of benznidazole treatment, were highly protected from challenge with both homologous and heterologous strains. There was a >99% reduction in parasite burden, with parasites frequently undetectable after homologous challenge. This level of protection was considerably greater than that achieved with recombinant vaccines. It was also independent of the route of infection or size of the challenge inoculum, and was long-lasting, with no significant diminution in immunity after almost a year. When the primary infection was benznidazole-treated after 4 days (before completion of the first cycle of intracellular infection), the degree of protection was much reduced, an outcome associated with a minimal T. cruzi-specific IFN-γ+ T cell response. CONCLUSIONS/SIGNIFICANCE: Our findings suggest that a protective Chagas disease vaccine must have the ability to eliminate parasites before they reach organs/tissues, such as the GI tract, where once established, they become largely refractory to the induced immune response.


Assuntos
Doença de Chagas/imunologia , Doença de Chagas/prevenção & controle , Imunidade Heteróloga , Vacinas Protozoárias/imunologia , Trypanosoma cruzi/imunologia , Vacinação/métodos , Animais , Modelos Animais de Doenças , Feminino , Camundongos Endogâmicos BALB C , Vacinas Protozoárias/administração & dosagem , Vacinas de Subunidades/administração & dosagem , Vacinas de Subunidades/imunologia , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/imunologia
16.
mBio ; 11(2)2020 04 07.
Artigo em Inglês | MEDLINE | ID: mdl-32265331

RESUMO

Middle East respiratory syndrome coronavirus (MERS-CoV) can cause severe and fatal acute respiratory disease in humans and remains endemic in the Middle East since first being identified in 2012. There are currently no approved vaccines or therapies available for MERS-CoV. In this study, we evaluated parainfluenza virus 5 (PIV5)-based vaccine expressing the MERS-CoV envelope spike protein (PIV5/MERS-S) in a human DPP4 knockin C57BL/6 congenic mouse model (hDPP4 KI). Following a single-dose intranasal immunization, PIV5-MERS-S induced neutralizing antibody and robust T cell responses in hDPP4 KI mice. A single intranasal administration of 104 PFU PIV5-MERS-S provided complete protection against a lethal challenge with mouse-adapted MERS-CoV (MERSMA6.1.2) and improved virus clearance in the lung. In comparison, single-dose intramuscular immunization with 106 PFU UV-inactivated MERSMA6.1.2 mixed with Imject alum provided protection to only 25% of immunized mice. Intriguingly, an influx of eosinophils was observed only in the lungs of mice immunized with inactivated MERS-CoV, suggestive of a hypersensitivity-type response. Overall, our study indicated that PIV5-MERS-S is a promising effective vaccine candidate against MERS-CoV infection.IMPORTANCE MERS-CoV causes lethal infection in humans, and there is no vaccine. Our work demonstrates that PIV5 is a promising vector for developing a MERS vaccine. Furthermore, success of PIV5-based MERS vaccine can be employed to develop a vaccine for emerging CoVs such as SARS-CoV-2, which causes COVID-19.


Assuntos
Infecções por Coronavirus/prevenção & controle , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/imunologia , Vacinas Virais/genética , Vacinas Virais/imunologia , Administração Intranasal , Animais , Anticorpos Antivirais/sangue , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/mortalidade , Modelos Animais de Doenças , Imunização , Camundongos , Camundongos Endogâmicos C57BL , Vírus da Parainfluenza 5/genética , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/genética , Vacinas Sintéticas/imunologia
17.
Poult Sci ; 99(3): 1275-1286, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32111305

RESUMO

Newcastle disease virus (NDV) is a major threat to the poultry industry worldwide, with a diversity of genotypes associated with severe economic losses in all poultry sectors. Class II genotype VII NDV are predominant in the Middle East and Asia, despite intensive vaccination programs using conventional live and inactivated NDV vaccines. In Egypt, the disease is continuously spreading, causing severe economical losses in the poultry industry. In this study; the protective efficacy of a commercial, inactivated recombinant genotype VII NDV-matched vaccine (KBNP-C4152R2L strain) against challenge with the velogenic NDV strain (Chicken/USC/Egypt/2015) was evaluated in commercial layers. Two vaccination regimes were used; live NDV genotype II (LaSota) vaccine on days 10, 18, and 120, with either the inactivated NDV genotype II regime or inactivated NDV genotype VII-matched vaccine regime on days 14, 42, and 120. The 2 regimes were challenged at the peak of egg production on week 26. Protection by the 2 regimes was evaluated after experimental infection, based on mortality rate, clinical signs, gross lesions, virus shedding, seroconversion, and egg production schedule. The results show that these 2 vaccination regimes protected commercial layer chickens against mortality, but some birds showed mild clinical signs and reduced egg production temporarily. However, the combination of live NDV genotype II and recombinant inactivated genotype VII vaccines provided better protection against virus shedding (20% and 0% vs. 60% and 40%) as assessed in tracheal swabs and (20% and 0% vs. 20% and 20%) in cloacal swabs collected at 3 and 5 D post challenge (dpc), respectively. In addition, egg production levels in birds receiving the inactivated NDV genotype VII-matched vaccine regime and in those given inactivated genotype II vaccines were 76.6, 79, 82, and 87.4% and 77.7, 72.5, 69, and 82.5% at 7, 14, 21, and 28 dpc, respectively. The results of this study indicate that recombinant genotype-matched inactivated vaccine along with a live attenuated vaccine can reduce virus shedding and improve egg production in commercial layers challenged with a velogenic genotype VII virus under field conditions. This regime may ensure a proper control strategy in layers.


Assuntos
Doença de Newcastle/prevenção & controle , Vírus da Doença de Newcastle/imunologia , Doenças das Aves Domésticas/prevenção & controle , Vacinação/tendências , Vacinação/veterinária , Vacinas Virais/administração & dosagem , Animais , Galinhas , Egito , Feminino , Genótipo , Vírus da Doença de Newcastle/genética , Vacinas Atenuadas/administração & dosagem , Vacinas Sintéticas/administração & dosagem
18.
Res Vet Sci ; 130: 184-192, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32199177

RESUMO

Cyprinid herpesvirus 3 (CyHV-3) is the etiological agent of koi herpersvirus disease (KHVD), which causes serious economic losses in global common carp and ornamental koi carp production of larvae as well as adult type fish. To control KHVD, vaccines against CyHV-3 utilizing different immunization routes have been developed, among them, oral vaccination is the most desirable method to prevent fish diseases occurring at the early larval stage. Here, we developed an oral subunit vaccine through the Saccharomyces cerevisiae cell surface display of CyHV-3 envelope protein pORF65, then, the recombinant yeast fed to Artemia which served as bio-encapsulation vector by subsequently feeding the common carp (Cyprinus carpio var. Jian) larvae. The fluorescent observation showed that the Artemia and S. cerevisiae could deliver intact antigen to the hindgut of carp larvae suggesting the possibility of the vector for oral immunization. On this basis, after three immunizations at a week interval, the oral vaccine induced high level of specific anti-pORF65 antibody. Meanwhile, a significant difference of immune-related genes expression occurred including cxca, IL-1ß, IFN-a1, lysozyme, IgM and CD8α between vaccined group and blank control group. In addition, 30% of relative percent survival of carp larvae after immunization was obtained post the animal infection assay, offered an certain immune protection. Our results indicated that the oral pORF65 subunit vaccine bioencapsulated in Artemia induced the activation of immune response and high level of antibodies, which could be served as an oral vaccine candidate for the prevention of CyHV-3 infection.


Assuntos
Antígenos Virais/imunologia , Doenças dos Peixes/imunologia , Infecções por Herpesviridae/veterinária , Herpesviridae/imunologia , Vacinas contra Herpesvirus/administração & dosagem , Vacinação/veterinária , Adjuvantes Imunológicos/administração & dosagem , Administração Oral , Animais , Artemia/química , Infecções por Herpesviridae/imunologia , Imunidade Inata/efeitos dos fármacos , Substâncias Protetoras/administração & dosagem , Saccharomyces cerevisiae/química , Vacinas Sintéticas/administração & dosagem , Proteínas do Envelope Viral/imunologia
19.
Comp Immunol Microbiol Infect Dis ; 70: 101470, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32208191

RESUMO

Brucellosis is a zoonotic disease threatening the public health and hindering the trade of animals and their products, which has a negative impact on the economic development of a country. Vaccination is the most effective way to control brucellosis. The recombinant vector vaccines are promising candidates for immunization in humans and animals. In this study, the gene encoding OMP19 antigen was primarily amplified and cloned into an expression vector called pT1NX, and then transformed to L. casei cell via electroporation technique. The expression was confirmed using specific antibody against the recombinant protein via immunological screening tests such as western blot and immunofluorescence assay. Finally, recombinant L. casei was orally fed to mice and the results were further recorded, indicating that the mice group which received OMP19 through L. casei based vaccine represented a very good general and mucosal immune responses protective against challenges with virulent B. abortus 544 strain compared with negative control recipient groups. Therefore, the vaccine produced in this research plan can be a very good candidate for protection against brucellosis.


Assuntos
Anticorpos Antibacterianos/sangue , Antígenos de Bactérias/imunologia , Proteínas da Membrana Bacteriana Externa/imunologia , Vacina contra Brucelose/imunologia , Brucelose/prevenção & controle , Lactobacillus casei/genética , Lipoproteínas/imunologia , Administração Oral , Animais , Antígenos de Bactérias/administração & dosagem , Proteínas da Membrana Bacteriana Externa/administração & dosagem , Vacina contra Brucelose/administração & dosagem , Brucella abortus , Brucelose/imunologia , Citocinas/imunologia , Feminino , Humanos , Imunidade Humoral , Imunidade nas Mucosas , Lipoproteínas/administração & dosagem , Camundongos , Camundongos Endogâmicos BALB C , Probióticos/administração & dosagem , Vacinação/métodos , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/imunologia
20.
PLoS Negl Trop Dis ; 14(3): e0007813, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32196487

RESUMO

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging tick-borne disease caused by SFTS virus (SFTSV) infection. Despite a gradual increase of SFTS cases and high mortality in endemic regions, no specific viral therapy nor vaccine is available. Here, we developed a single recombinant plasmid DNA encoding SFTSV genes, Gn and Gc together with NP-NS fusion antigen, as a vaccine candidate. The viral antigens were fused with Fms-like tyrosine kinase-3 ligand (Flt3L) and IL-12 gene was incorporated into the plasmid to enhance cell-mediated immunity. Vaccination with the DNA provides complete protection of IFNAR KO mice upon lethal SFTSV challenge, whereas immunization with a plasmid without IL-12 gene resulted in partial protection. Since we failed to detect antibodies against surface glycoproteins, Gn and Gc, in the immunized mice, antigen-specific cellular immunity, as confirmed by enhanced antigen-specific T cell responses, might play major role in protection. Finally, we evaluated the degree of protective immunity provided by protein immunization of the individual glycoprotein, Gn or Gc. Although both protein antigens induced a significant level of neutralizing activity against SFTSV, Gn vaccination resulted in relatively higher neutralizing activity and better protection than Gc vaccination. However, both antigens failed to provide complete protection. Given that DNA vaccines have failed to induce sufficient immunogenicity in human trials when compared to protein vaccines, optimal combinations of DNA and protein elements, proper selection of target antigens, and incorporation of efficient adjuvant, need to be further investigated for SFTSV vaccine development.


Assuntos
Adjuvantes Imunológicos/farmacologia , Antígenos Virais/imunologia , Infecções por Bunyaviridae/prevenção & controle , Interleucina-12/administração & dosagem , Phlebovirus/imunologia , Vacinas de DNA/imunologia , Vacinas Virais/imunologia , Animais , Antígenos Virais/genética , Modelos Animais de Doenças , Feminino , Imunidade Celular , Interleucina-12/farmacologia , Camundongos Knockout , Phlebovirus/genética , Plasmídeos/administração & dosagem , Linfócitos T/imunologia , Vacinas de DNA/administração & dosagem , Vacinas de DNA/genética , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/genética , Vacinas Sintéticas/imunologia , Vacinas Virais/administração & dosagem , Vacinas Virais/genética
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