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1.
Educ Technol Res Dev ; 72(2): 973-996, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38765935

RESUMO

Privacy is a central issue in the digitalization of society and directly concerns all Internet users. Privacy education is part of the picture of a more just digital society: it aims at making users more aware of the importance of their data and of the technical and financial tools and processes that involve their personal data. Nonetheless, privacy education is confronted with a paradox: while people perceive the importance of privacy, they seldom take action to actually protect their personal data. iBuddy is a narrative simulation-based session inspired by research evidence about the privacy paradox and aims to (a) enhancing awareness and (b) promoting the uptake of privacy-safe behaviors for secondary and higher students (age range 11-20). The paper presents the design and development of the simulation and of the following modular debriefing, as a case study in evidence-based collaborative instructional design and in the instructional used of digital technology. The evaluation of iBuddy, which combined a post-session satisfaction and perceived learning survey (N = 978) and a follow-up survey (N = 124), provides insights in the novel domain of privacy education. Results suggests that iBuddy sessions are engaging, effective and conducive to medium-term behavioral change, thus indirectly confirming the design assumptions about how to tackle the privacy paradox through a simulation-based approach.

2.
J Med Virol ; 95(5): e28778, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-37212258

RESUMO

Monkeypox virus (MPXV) is a zoonotic disease endemic in the rainforest countries of Central and West Africa. Understanding the immune response in zoonosis is fundamental to prevent and contrast viral spreading. MPXV is a close relative of Variola (smallpox) virus and vaccination with vaccinia virus gives approximatively 85% of protection against MPXV. With the emergence of the recent MPXV outbreak, JYNNEOS vaccine has been proposed to individuals at high-risk of exposure. Comparative data on MPXV immune response in vaccinated or infected subjects are still limited. Here we set-up an immunofluorescence method for the evaluation of humoral response elicited by natural infection and healthy vaccinated subjects, including historically smallpox-vaccinated individuals and newly vaccinated subjects. Neutralization assay was also included, and in vaccinated subjects, cell-mediated response was evaluated. We observed that the natural infection produces a strong immune response that can control the disease. In naïve subjects, a second dose boosts the serological response to levels similar to those of the MPXV patients. Last, smallpox-vaccinated controls retain a degree of protection, even after years from vaccination, most visible in the t-cellular response.


Assuntos
Mpox , Varíola , Humanos , Monkeypox virus , Varíola/prevenção & controle , Mpox/epidemiologia , Mpox/prevenção & controle , Vaccinia virus , Imunidade
3.
Int J Mol Sci ; 24(7)2023 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-37047704

RESUMO

The role and durability of the immunogenicity of the BNT162b2 mRNA vaccine against severe acute respiratory virus 2 (SARS-CoV-2), in cancer patients one year after receiving the third dose have to be elucidated. We have prospectively evaluated the long-term immunogenicity of the third dose of the SARS-CoV-2 BNT162b2 mRNA vaccine in 55 patients undergoing active treatment. Neutralizing antibody (NT Ab) titers against Omicron variants and total anti-trimeric S IgG levels were measured one year after the third dose. Heparinized whole-blood samples were used for the assessment of the SARS-CoV-2 interferon-γ release assay (IGRA). Thirty-seven patients (67.3%) showed positive total anti-trimeric S IgG one year after the third dose. Looking at the T-cell response against the spike protein, the frequency of responder patients did not decrease significantly between six and twelve months after the third dose. Finally, less than 20% of cancer patients showed an undetectable NT Ab titer against BA.1 and BA.5 variants of concern (VOCs). Underlying therapies seem to not affect the magnitude or frequency of the immune response. Our work underlines the persistence of humoral and cellular immune responses against BNT162b2 in a cohort of cancer patients one year after receiving the third dose, regardless of the type of underlying therapy.


Assuntos
COVID-19 , Neoplasias , Viroses , Humanos , Vacina BNT162 , Vacinas contra COVID-19 , Seguimentos , SARS-CoV-2 , COVID-19/prevenção & controle , Neoplasias/terapia , Anticorpos Neutralizantes , Imunidade , Imunoglobulina G , Anticorpos Antivirais , Vacinas de mRNA
4.
Transfusion ; 62(6): 1171-1176, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35426131

RESUMO

BACKGROUND: Novel SARS-CoV-2 variants of concern (VOC) Delta and Omicron are able to escape some monoclonal antibody therapies, making again COVID-19 convalescent plasma (CCP) a potential frontline treatment. STUDY DESIGN/METHODS: In this study, we investigated the kinetics of anti-SARS-CoV-2 neutralizing antibodies (nAbs) against VOCs Delta and Omicron in vaccine breakthrough infected plasma donors. Serum samples from 19 donors were collected at the time of plasma donation and tested for anti-SARS-CoV-2 nAbs (using live authentic VOC viral neutralization test) and IgG (Liaison® SARS-CoV-2 S1/S2 and Liaison® SARS-CoV-2 TrimericS IgG assays, DiaSorin). Measures were correlated with different variables, including the time between last vaccine dose and CCP donation, and time between SARS-COV-2 infection and CCP donation. RESULTS: nAb titers against VOC Delta and Omicron were directly related to the time interval since last vaccine dose to CCP donation, but inversely related to time since COVID19 breakthrough infection. DISCUSSION: SARS-CoV-2 breakthrough infection in vaccinated in donors boosts nAb titers against VOCs Delta and Omicron, but such titers decay shortly after infection. Therefore, CCP must be collected early after vaccine breakthrough infection.


Assuntos
COVID-19 , Vacinas Virais , Anticorpos Neutralizantes , Anticorpos Antivirais , Doadores de Sangue , COVID-19/prevenção & controle , COVID-19/terapia , Humanos , Imunização Passiva , Imunoglobulina G , Testes de Neutralização , SARS-CoV-2 , Soroterapia para COVID-19
5.
Transfus Apher Sci ; 61(4): 103398, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35227599

RESUMO

BACKGROUND: Test the ability of Mirasol Pathogen Reduction Technology (PRT, Terumo BCT, Lakewood Co, USA) treatment with riboflavin and ultraviolet light (R + UV) in reducing SARS-CoV-2 infectivity while maintaining blood product quality. MATERIAL AND METHODS: SARS-CoV-2 strains were isolated and titrated to prepare cell free virus for plasma units infection. The units were then under treatment with Mirasol PRT. The infectious titers were determined before and after treatment with an in house microtitration assay on Vero E6 cells. Thirty-six plasma pool bags underwent PRT treatment. RESULTS: In all the experiments, the measured titer following riboflavin and UV treatment was below the limit of detection of microtitration assay for all the different SARS-CoV-2 strains. Despite the high copies number detected by RT-PCR for each viral strain after treatment, viruses were completely inactivated and not able to infect VERO E6 cells. CONCLUSION: Riboflavin and UV light treatment effectively reduced the virus titers of human plasma to the limit of detection in tissue culture, regardless of the strain. These data suggest that pathogen reduction in blood products highlight the safety of CP therapy procedures for critically ill COVID-19 patients, while maintaining blood product quality.


Assuntos
Tratamento Farmacológico da COVID-19 , SARS-CoV-2 , Humanos , Riboflavina/farmacologia , Raios Ultravioleta
6.
Exp Parasitol ; 239: 108303, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35716768

RESUMO

Countless research is carried out until new discoveries are transformed into products or services available to the population. This trajectory can be slower and more costly or even impossible when irreproducible data are obtained in the most diverse fields of science. Thus, quality management appears as an essential tool to guarantee the reliability of academic research results. In this work, we demonstrate the applied strategy to implement a Quality Management System (QMS) in a research laboratory in Veterinary Parasitology and we highlight the adaptable quality requirements in this scientific research environment. For this, the Plan-Do-Check-Act (PDCA) quality tool was used, and two internal audits were performed, one before and one after implementation. The audits reached 67 (41.36%) and 157 (96.91%) points before and after implementation, respectively, with a significant difference between the moments studied. Thus, we demonstrate that the adoption of QMS principles in research is feasible. The methodology applied in this work can be adopted by managers from other laboratories interested in the implementation of quality standards as a support in the reproducibility of research.


Assuntos
Laboratórios , Controle de Qualidade , Reprodutibilidade dos Testes
7.
Euro Surveill ; 25(24)2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32583766

RESUMO

We evaluated SARS-CoV-2 RNA and neutralising antibodies in blood donors (BD) residing in the Lodi Red Zone, Italy. Of 390 BDs recruited after 20 February 2020 - when the first COVID-19 case in Lombardy was identified, 91 (23%) aged 19-70 years were antibody positive. Viral RNA was detected in an additional 17 (4.3%) BDs, yielding ca 28% (108/390) with evidence of virus exposure. Five stored samples collected as early as 12 February were seropositive.


Assuntos
Anticorpos Neutralizantes/imunologia , Betacoronavirus/imunologia , Infecções por Coronavirus/epidemiologia , Pneumonia Viral/epidemiologia , Adulto , Idoso , Doadores de Sangue , COVID-19 , Teste para COVID-19 , Vacinas contra COVID-19 , Técnicas de Laboratório Clínico , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/terapia , Feminino , Humanos , Imunização Passiva , Itália/epidemiologia , Masculino , Pessoa de Meia-Idade , Testes de Neutralização , Pandemias , Pneumonia Viral/imunologia , Pneumonia Viral/terapia , Prevalência , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , SARS-CoV-2 , Estudos Soroepidemiológicos , Adulto Jovem , Soroterapia para COVID-19
9.
Molecules ; 23(1)2018 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-29303991

RESUMO

The VAO flavoprotein family consists mostly of oxidoreductases harboring a covalently linked flavin cofactor. The linkage can be either monocovalent at position 8 with a histidine or tyrosine or bicovalent at position 8 with a histidine and at position 6 with a cysteine. Bicovalently bound flavoproteins show a preference for bulkier substrates such as oligosaccharides or secondary metabolites. The genome of the thermophilic fungus Myceliophthora thermophila C1 was found to be rich in genes encoding putative covalent VAO-type flavoproteins. Enzymes from this fungus have the advantage of being rather thermostable and homologous overexpression in M. thermophila C1 is feasible. Recently we discovered a new and VAO-type carbohydrate oxidase from this fungus: xylooligosaccharide oxidase. In this study, two other putative VAO-type oxidases, protein sequence XP_003663615 (MtVAO615) and XP_003665713 (MtVAO713), were expressed in M. thermophila C1, purified and characterized. Enzyme MtVAO615 was found to contain a bicovalently bound FAD, while enzyme MtVAO713 contained a monocovalent histidyl-bound FAD. The crystal structures of both proteins were obtained which revealed atypical active site architectures. It could be experimentally verified that both proteins, when reduced, rapidly react with molecular oxygen, a hallmark of flavoprotein oxidases. A large panel of alcohols, including carbohydrates, steroids and secondary alcohols were tested as potential substrates. For enzyme MtVAO713 low oxidase activity was discovered towards ricinoleic acid.


Assuntos
Ascomicetos/enzimologia , Flavoproteínas/química , Proteínas Fúngicas/química , Oxirredutases/química , Sequência de Aminoácidos , Domínio Catalítico , Flavina-Adenina Dinucleotídeo/química , Flavinas/química , Flavoproteínas/isolamento & purificação , Proteínas Fúngicas/isolamento & purificação , Modelos Moleculares , Oxirredução , Oxirredutases/isolamento & purificação , Oxigênio/química , Filogenia , Ligação Proteica , Especificidade por Substrato
10.
J Biol Chem ; 291(45): 23709-23718, 2016 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-27629413

RESUMO

By inspection of the predicted proteome of the fungus Myceliophthora thermophila C1 for vanillyl-alcohol oxidase (VAO)-type flavoprotein oxidases, a putative oligosaccharide oxidase was identified. By homologous expression and subsequent purification, the respective protein could be obtained. The protein was found to contain a bicovalently bound FAD cofactor. By screening a large number of carbohydrates, several mono- and oligosaccharides could be identified as substrates. The enzyme exhibits a strong substrate preference toward xylooligosaccharides; hence it is named xylooligosaccharide oxidase (XylO). Chemical analyses of the product formed upon oxidation of xylobiose revealed that the oxidation occurs at C1, yielding xylobionate as product. By elucidation of several XylO crystal structures (in complex with a substrate mimic, xylose, and xylobiose), the residues that tune the unique substrate specificity and regioselectivity could be identified. The discovery of this novel oligosaccharide oxidase reveals that the VAO-type flavoprotein family harbors oxidases tuned for specific oligosaccharides. The unique substrate profile of XylO hints at a role in the degradation of xylan-derived oligosaccharides by the fungus M. thermophila C1.


Assuntos
Glucuronatos/metabolismo , Oligossacarídeos/metabolismo , Oxirredutases/metabolismo , Sordariales/enzimologia , Sequência de Aminoácidos , Cristalografia por Raios X , Dissacarídeos/metabolismo , Flavina-Adenina Dinucleotídeo/metabolismo , Modelos Moleculares , Oxirredução , Oxirredutases/química , Conformação Proteica , Alinhamento de Sequência , Sordariales/química , Sordariales/metabolismo , Especificidade por Substrato , Xilanos/metabolismo
11.
Biotechnol Bioeng ; 112(6): 1074-80, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25565162

RESUMO

Chitooligosaccharide oxidase from Fusarium graminearum (ChitO) oxidizes N-acetyl-D-glucosamine (GlcNAc) and its oligomers with high efficiency at the C1-hydroxyl moiety while it shows poor or no activity with other carbohydrates. By sequence and structural comparison with other known carbohydrate oxidases (glucooligosaccharide oxidase from Acremonium strictum and lactose oxidase from Microdochium nivale) eleven mutants were designed to redirect the catalytic scope of ChitO for improved oxidation of lactose, cellobiose and maltose. The catalytic properties of the most interesting mutants were further improved by combining single mutations. This has resulted in the creation of a set of ChitO variants that display totally different substrate tolerances. One ChitO variant shows a dramatic improvement in catalytic efficiency towards oxidation of glucose, cellobiose, lactose, and maltose. We also describe a ChitO variant with the highest catalytic efficiency in GlcNAc oxidation so far reported in the literature.


Assuntos
Acetilglucosamina/metabolismo , Quitina/análogos & derivados , Fusarium/enzimologia , Mutagênese Sítio-Dirigida , Oxirredutases/genética , Oxirredutases/metabolismo , Substituição de Aminoácidos , Celobiose/metabolismo , Quitina/metabolismo , Quitosana , Glucose/metabolismo , Lactose/metabolismo , Maltose/metabolismo , Modelos Moleculares , Oligossacarídeos , Oxirredução , Oxirredutases/química , Conformação Proteica , Especificidade por Substrato
12.
Phytopathology ; 105(2): 199-209, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25185010

RESUMO

Ampelomyces quisqualis is a mycoparasite of a diverse range of phytopathogenic fungi associated with the powdery mildew disease. Among them are several Erysiphaceae species with great economic impact on high-value crops such as grape. Due to its ability to parasitize and prevent the spread of powdery mildews, A. quisqualis has received considerable attention for its biocontrol potential. However, and in sharp contrast to the extensively studied biocontrol species belonging to the genus Trichoderma, little is known about the biology of A. quisqualis at the molecular and genetic levels. We present the first genome-wide transcription profiling in A. quisqualis during host-induced germination. A total of 1,536 putative genes showed significant changes in transcription during the germination of A. quisqualis. This finding denotes an extensive transcriptional reprogramming of A. quisqualis induced by the presence of the host. Several upregulated genes were predicted to encode for putative mycoparasitism-related proteins such as secreted proteases, virulence factors, and proteins related to toxin biosynthesis. Our data provide the most comprehensive sequence resource currently available for A. quisqualis in addition to offering valuable insights into the biology of A. quisqualis and its mycoparasitic lifestyle. Eventually, this may improve the biocontrol capacity of this mycoparasite.


Assuntos
Ascomicetos/genética , Doenças das Plantas/prevenção & controle , Transcriptoma , Vitis/microbiologia , Ascomicetos/fisiologia , Agentes de Controle Biológico , DNA Complementar/química , DNA Complementar/genética , Perfilação da Expressão Gênica , Biblioteca Gênica , Sequenciamento de Nucleotídeos em Larga Escala , Análise de Sequência com Séries de Oligonucleotídeos , Filogenia , Doenças das Plantas/microbiologia , RNA Fúngico/genética
13.
bioRxiv ; 2024 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-38370806

RESUMO

Currently approved COVID-19 vaccines prevent symptomatic infection, hospitalization, and death from the disease. However, repeated homologous boosters, while considered a solution for severe forms of the disease caused by new SARS-CoV-2 variants in elderly individuals and immunocompromised patients, cannot provide complete protection against breakthrough infections. This highlights the need for alternative platforms for booster vaccines. In our previous study, we assessed the boost effect of the SARS-CoV-2 Beta S1 recombinant protein subunit vaccine (rS1Beta) in aged mice primed with an adenovirus-based vaccine expressing SARS-CoV-2-S1 (Ad5.S1) via subcutaneous injection or intranasal delivery, which induced robust humoral immune responses (1). In this follow-up study, we demonstrated that a second booster dose of a non-adjuvanted recombinant Omicron (BA.1) S1 subunit vaccine with Toll-like receptor 4 (TLR4) agonist RS09 (rS1RS09OM) was effective in stimulating strong S1-specific immune responses and inducing significantly high neutralizing antibodies against the Wuhan, Delta, and Omicron variants in 100-week-old mice. Importantly, the second booster dose elicits cross-reactive antibody responses, resulting in ACE2 binding inhibition against the spike protein of SARS-CoV-2 variants, including Omicron (BA.1) and its subvariants. Interestingly, the levels of IgG and neutralizing antibodies correlated with the level of ACE2 inhibition in the booster serum samples, although Omicron S1-specific IgG level showed a weaker correlation compared to Wuhan S1-specific IgG level. Furthermore, we compared the immunogenic properties of the rS1 subunit vaccine in young, middle-aged, and elderly mice, resulting in reduced immunogenicity with age, especially an impaired Th1-biased immune response in aged mice. Our findings demonstrate that the new variant of concern (VOC) rS1 subunit vaccine as a second booster has the potential to offer cross-neutralization against a broad range of variants and to improve vaccine effectiveness against newly emerging breakthrough SARS-CoV-2 variants in elderly individuals who were previously primed with the authorized vaccines.

14.
Int Immunopharmacol ; 129: 111569, 2024 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-38340419

RESUMO

The COVID-19 pandemic has underscored the pressing need for safe and effective booster vaccines, particularly in considering the emergence of new SARS-CoV-2 variants and addressing vaccine distribution inequalities. Dissolving microneedle array patches (MAP) offer a promising delivery method, enhancing immunogenicity and improving accessibility through the skin's immune potential. In this study, we evaluated a microneedle array patch-based S1 subunit protein COVID-19 vaccine candidate, which comprised a bivalent formulation targeting the Wuhan and Beta variant alongside a monovalent Delta variant spike proteins in a murine model. Notably, the second boost of homologous bivalent MAP-S1(WU + Beta) induced a 15.7-fold increase in IgG endpoint titer, while the third boost of heterologous MAP-S1RS09Delta yielded a more modest 1.6-fold increase. Importantly, this study demonstrated that the administration of four doses of the MAP vaccine induced robust and long-lasting immune responses, persisting for at least 80 weeks. These immune responses encompassed various IgG isotypes and remained statistically significant for one year. Furthermore, neutralizing antibodies against multiple SARS-CoV-2 variants were generated, with comparable responses observed against the Omicron variant. Overall, these findings emphasize the potential of MAP-based vaccines as a promising strategy to combat the evolving landscape of COVID-19 and to deliver a safe and effective booster vaccine worldwide.


Assuntos
Vacinas contra COVID-19 , COVID-19 , Animais , Humanos , Camundongos , Subunidades Proteicas , SARS-CoV-2 , Vacinas de Subunidades Proteicas , Pandemias , COVID-19/prevenção & controle , Anticorpos Neutralizantes , Imunoglobulina G , Anticorpos Antivirais
15.
Travel Med Infect Dis ; 59: 102698, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38556220

RESUMO

BACKGROUND: Mpox virus (MPXV) has recently spread outside of sub-Saharan Africa. This large multicentre study was conducted in Lombardy, the most densely populated Italian region accounting for more than 40% of Italian cases. The present study aims to: i) evaluate the presence and the shedding duration of MPXV DNA in different body compartments correlating the MPXV viability with the time to onset of symptoms; ii) provide evidence of MPXV persistence in different body compartment as a source of infection and iii) characterize the MPXV evolution by whole genome sequencing (WGS) during the outbreak occurred in Italy. MATERIAL AND METHODS: The study included 353 patients with a laboratory-confirmed diagnosis of MPXV infection screened in several clinical specimens in the period May 24th - September 1st, 2022. Viral isolation was attempted from different biological matrices and complete genome sequencing was performed for 61 MPXV strains. RESULTS: MPXV DNA detection was more frequent in the skin (94.4%) with the longest median time of viral clearance (16 days). The actively-replicating virus in cell culture was obtained for 123/377 (32.6%) samples with a significant higher viral quantity on isolation positive samples (20 vs 31, p < 0.001). The phylogenetic analysis highlighted the high genetic identity of the MPXV strains collected, both globally and within the Lombardy region. CONCLUSION: Skin lesion is gold standard material and the high viral load and the actively-replicating virus observed in genital sites confirms that sexual contact plays a key role in the viral transmission.


Assuntos
DNA Viral , Surtos de Doenças , Eliminação de Partículas Virais , Humanos , Itália/epidemiologia , DNA Viral/genética , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Filogenia , Adulto Jovem , Infecções por Picornaviridae/epidemiologia , Infecções por Picornaviridae/virologia , Adolescente , Sequenciamento Completo do Genoma , Idoso , Criança
16.
Nat Commun ; 14(1): 6874, 2023 10 28.
Artigo em Inglês | MEDLINE | ID: mdl-37898607

RESUMO

Full Laboratory Automation is revolutionizing work habits in an increasing number of clinical microbiology facilities worldwide, generating huge streams of digital images for interpretation. Contextually, deep learning architectures are leading to paradigm shifts in the way computers can assist with difficult visual interpretation tasks in several domains. At the crossroads of these epochal trends, we present a system able to tackle a core task in clinical microbiology, namely the global interpretation of diagnostic bacterial culture plates, including presumptive pathogen identification. This is achieved by decomposing the problem into a hierarchy of complex subtasks and addressing them with a multi-network architecture we call DeepColony. Working on a large stream of clinical data and a complete set of 32 pathogens, the proposed system is capable of effectively assist plate interpretation with a surprising degree of accuracy in the widespread and demanding framework of Urinary Tract Infections. Moreover, thanks to the rich species-related generated information, DeepColony can be used for developing trustworthy clinical decision support services in laboratory automation ecosystems from local to global scale.


Assuntos
Ecossistema , Infecções Urinárias , Humanos , Bactérias , Automação Laboratorial
17.
J Infect Public Health ; 16(5): 736-740, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36958168

RESUMO

INTRODUCTION: Although the potential role of inanimate surfaces in SARS-CoV-2 transmission has yet to be adequately assessed, it is still routine practice to apply deep and expensive environmental disinfection protocols. The aim of this study was to verify the presence of viable virus on different surfaces exposed to droplets released by coughing in SARS-CoV-2 RNA positive patients. METHODS: Patients admitted to hospital with a positive SARS-CoV-2 real-time (RT)-PCR swab were asked to cough on steel, cardboard, plastic and their hands. Surfaces were tested at baseline (T0) and at different timepoints thereafter using swabs dipped in medium, and quickly seeded on VERO E6 cells that were checked every other day for cytopathic effect (CPE). Laboratory-propagated SARS-CoV-2 strains were examined at the same time points and on identical materials. RESULTS: Ten RNA-positive patients were enrolled into the study. The median cycle threshold value was 20.7 (range 13-28.3). Nasopharyngeal swabs from 3 of the patients yielded viable virus 2-10 days post-inoculation. However, in none of the patients was it possible to isolate viable SARS-CoV-2 from sputum under identical experimental conditions. A CPE was instead already visible using laboratory-propagated SARS-CoV-2 strains at 20', 60', 180' while an effect at 24 h required a 6-day incubation. CONCLUSION: The evidence emerging from this real-life study suggests that droplets delivered by SARS-CoV-2 infected patients on common inanimate surfaces did not contain viable virus. In contrast, and in line with several laboratory-based experiments, in vitro adapted viruses could survive and grow on the same fomites.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , SARS-CoV-2/genética , RNA Viral/genética , Fômites , Hospitais
18.
Microbiol Spectr ; 11(3): e0436322, 2023 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-37162333

RESUMO

The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants has raised concerns about reduced vaccine effectiveness and the increased risk of infection, and while repeated homologous booster shots are recommended for elderly and immunocompromised individuals, they cannot completely protect against breakthrough infections. In our previous study, we assessed the immunogenicity of an adenovirus-based vaccine expressing SARS-CoV-2 S1 (Ad5.S1) in mice, which induced robust humoral and cellular immune responses (E. Kim, F. J. Weisel, S. C. Balmert, M. S. Khan, et al., Eur J Immunol 51:1774-1784, 2021, https://doi.org/10.1002/eji.202149167). In this follow-up study, we found that the mice had high titers of anti-S1 antibodies 1 year after vaccination, and one booster dose of the nonadjuvanted rS1Beta (recombinant S1 protein of SARS-CoV-2 Beta [B.1.351]) subunit vaccine was effective at stimulating strong long-lived S1-specific immune responses and inducing significantly high neutralizing antibodies against Wuhan, Beta, and Delta strains, with 3.6- to 19.5-fold increases. Importantly, the booster dose also elicited cross-reactive antibodies, resulting in angiotensin-converting enzyme 2 (ACE2) binding inhibition against spikes of SARS-CoV-2, including Omicron variants, persisting for >28 weeks after booster vaccination. Interestingly, the levels of neutralizing antibodies were correlated not only with the level of S1 binding IgG but also with ACE2 inhibition. Our findings suggest that the rS1Beta subunit vaccine candidate as a booster has the potential to offer cross-neutralization against broad variants and has important implications for the vaccine control of newly emerging breakthrough SARS-CoV-2 variants in elderly individuals primed with adenovirus-based vaccines like AZD1222 and Ad26.COV2.S. IMPORTANCE Vaccines have significantly reduced the incidences of severe coronavirus disease 2019 (COVID-19) cases and deaths. However, the emergence of SARS-CoV-2 variants has raised concerns about their increased transmissibility and ability to evade neutralizing antibodies, especially among elderly individuals who are at higher risks of mortality and reductions of vaccine effectiveness. To address this, a heterologous booster vaccination strategy has been considered as a solution to protect the elderly population against breakthrough infections caused by emerging variants. This study evaluated the booster effect of an S1 subunit vaccine in aged mice that had been previously primed with adenoviral vaccines, providing valuable preclinical evidence for elderly people vaccinated with the currently approved COVID-19 vaccines. This study confirms the potential for using the S1 subunit vaccine as a booster to enhance cross-neutralizing antibodies against emerging variants of concern.


Assuntos
COVID-19 , Imunidade Humoral , Idoso , Humanos , Animais , Camundongos , SARS-CoV-2/genética , Enzima de Conversão de Angiotensina 2 , Ad26COVS1 , Vacinas contra COVID-19 , ChAdOx1 nCoV-19 , Seguimentos , COVID-19/prevenção & controle , Vacinação , Anticorpos Neutralizantes , Infecções Irruptivas , Anticorpos Antivirais
19.
bioRxiv ; 2023 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-36993692

RESUMO

The COVID-19 pandemic has highlighted the need for safe and effective vaccines to be rapidly developed and distributed worldwide, especially considering the emergence of new SARS-CoV-2 variants. Protein subunit vaccines have emerged as a promising approach due to their proven safety record and ability to elicit robust immune responses. In this study, we evaluated the immunogenicity and efficacy of an adjuvanted tetravalent S1 subunit protein COVID-19 vaccine candidate composed of the Wuhan, B.1.1.7 variant, B.1.351 variant, and P.1 variant spike proteins in a nonhuman primate model with controlled SIVsab infection. The vaccine candidate induced both humoral and cellular immune responses, with T- and B cell responses mainly peaking post-boost immunization. The vaccine also elicited neutralizing and cross-reactive antibodies, ACE2 blocking antibodies, and T-cell responses, including spike specific CD4+ T cells. Importantly, the vaccine candidate was able to generate Omicron variant spike binding and ACE2 blocking antibodies without specifically vaccinating with Omicron, suggesting potential broad protection against emerging variants. The tetravalent composition of the vaccine candidate has significant implications for COVID-19 vaccine development and implementation, providing broad antibody responses against numerous SARS-CoV-2 variants.

20.
mBio ; 14(5): e0207023, 2023 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-37830800

RESUMO

IMPORTANCE: The study provides important insights into the immunogenicity and efficacy of a tetravalent protein subunit vaccine candidate against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The vaccine induced both humoral and cellular immune responses in nonhuman primates with controlled SIVagm infection and was able to generate Omicron variant-specific antibodies without specifically vaccinating with Omicron. These findings suggest that the tetravalent composition of the vaccine candidate could provide broad protection against multiple SARS-CoV-2 variants while minimizing the risk of immune escape and the emergence of new variants. Additionally, the use of rhesus macaques with controlled SIVsab infection may better represent vaccine immunogenicity in humans with chronic viral diseases, highlighting the importance of preclinical animal models in vaccine development. Overall, the study provides valuable information for the development and implementation of coronavirus disease 2019 vaccines, particularly for achieving global vaccine equity and addressing emerging variants.


Assuntos
COVID-19 , SARS-CoV-2 , Animais , Humanos , Macaca mulatta , COVID-19/prevenção & controle , Vacinação , Vacinas contra COVID-19 , Imunidade Celular , Anticorpos Antivirais , Anticorpos Neutralizantes , Glicoproteína da Espícula de Coronavírus
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