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1.
Front Neurol ; 15: 1400455, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38711559

RESUMO

Purpose: The significance of atraumatic electrode array (EA) insertion in cochlear implant (CI) surgery is widely acknowledged, with consensus that forces due to EA insertion are directly correlated with insertion trauma. Unfortunately, the manual perception of these forces through haptic feedback is inherently limited, and techniques for in vivo force measurements to monitor the insertion are not yet available. Addressing this gap, we developed of a force-sensitive insertion tool capable of capturing real-time insertion forces during standard CI surgery. Methods: This paper describes the tool and its pioneering application in a clinical setting and reports initial findings from an ongoing clinical study. Data and experiences from five patients have been evaluated so far, including force profiles of four patients. Results: The initial intraoperative experiences are promising, with successful integration into the conventional workflow. Feasibility of in vivo insertion force measurement and practicability of the tool's intraoperative use could be demonstrated. The recorded in vivo insertion forces show the expected rise with increasing insertion depth. Forces at the end of insertion range from 17.2 mN to 43.6 mN, while maximal peak forces were observed in the range from 44.8 mN to 102.4 mN. Conclusion: We hypothesize that this novel method holds the potential to assist surgeons in monitoring the insertion forces and, thus, minimizing insertion trauma and ensuring better preservation of residual hearing. Future data recording with this tool can form the basis of ongoing research into the causes of insertion trauma, paving the way for new and improved prevention strategies.

2.
J Infect Dev Ctries ; 18(4): 556-564, 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38728629

RESUMO

INTRODUCTION: Unrecognized Ebola Virus Disease (EVD) can lead to multiple chains of transmissions if the first caretakers are not trained and prepared. This study aimed to assess healthcare workers (HCWs) preparedness in private hospitals located in Kampala, to detect, respond and prevent EVD. METHODOLOGY: A descriptive cross-sectional study was carried out among HCWs in direct clinical care provision in four private hospitals, and in one Ebola Treatment Unit (ETU) using a self-administered questionnaire from March to June 2020. RESULTS: 222 HCWs agreed to participate aged from 19 to 64 years and with 6 months to 38 years of practice where most were nurses (44%). 3/5 hospitals did not have written protocols on EVD case management, and only one (ETU) had an exclusive emergency team. 59% were not sure whether contact tracing was taking place. Private hospitals were not included in EVD trainings organized by the Ministry of Health (MoH). In addition, HCWs in private hospitals were not empowered by the MoH to take part in EVD case management. Despite these shortcomings, only 66% of HCWs showed an interest to be immunized. Knowledge about potential Ebola vaccines was generally poor. CONCLUSIONS: In Kampala, Uganda, establishment of a more comprehensive preparedness and response strategy for EVD outbreaks is imperative for HCWs in private facilities, including a wide vaccination educational program on Ebola vaccination. The findings from this study if addressed will likely improve the preparedness and management of future Ebola outbreaks in Uganda.


Assuntos
Pessoal de Saúde , Doença pelo Vírus Ebola , Hospitais Privados , Humanos , Doença pelo Vírus Ebola/prevenção & controle , Doença pelo Vírus Ebola/epidemiologia , Uganda/epidemiologia , Estudos Transversais , Pessoal de Saúde/estatística & dados numéricos , Adulto , Hospitais Privados/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Feminino , Adulto Jovem , Inquéritos e Questionários , Epidemias/prevenção & controle
4.
Biologicals ; 85: 101723, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37976940

RESUMO

In February 2023, a meeting about correlates of protection (CoPs) against COVID-19 was organized by the International Alliance for Biological Standardization, the European Plotkin Institute for Vaccinology, and Vaccinopolis. The meeting aimed at reviewing the evidence, drawing conclusions, and identifying knowledge gaps. Collection of evidence is not straightforward. Neutralizing antibodies correlate with protection and are used for immunobridging studies within and between vaccine platforms for approval of new COVID-19 vaccines. In preparation for the next pandemic, it is vital that rapidly authorized initial vaccines are available to perform immunobridging studies very early. Additional components of the immune response likely contribute to protection against symptomatic infection. Current evidence is strongest for T lymphocytes and binding antibodies. Further studies are needed to consolidate this evidence and define their potential role in the evaluation of vaccines. For evaluation of mucosal vaccines, identifying CoPs against infection and transmission is key; further research is needed to identify and standardize methods suitable for clinical studies. CoPs for broadly protective beta-coronavirus vaccines remain a critical area of research. The knowledge, expertise, and capacity exist to conduct clinical studies using different designs in different populations to discover and validate CoPs, facilitating and accelerating evaluation of novel vaccines/vaccination platforms.


Assuntos
Vacinas contra COVID-19 , COVID-19 , Humanos , COVID-19/prevenção & controle , Anticorpos Neutralizantes , Pandemias/prevenção & controle , Vacinação , Anticorpos Antivirais
5.
Artigo em Inglês | MEDLINE | ID: mdl-37204650

RESUMO

PURPOSE: The trajectory along which the cochlear implant electrode array is inserted influences the insertion forces and the probability for intracochlear trauma. Controlling the trajectory is especially relevant for reproducible conditions in electrode insertion tests. Using ex vivo cochlear specimens, manual alignment of the invisibly embedded cochlea is imprecise and hardly reproducible. The aim of this study was to develop a method for creating a 3D printable pose setting adapter to align a specimen along a desired trajectory toward an insertion axis. METHODS: Planning points of the desired trajectory into the cochlea were set using CBCT images. A new custom-made algorithm processed these points for automated calculation of a pose setting adapter. Its shape ensures coaxial positioning of the planned trajectory to both the force sensor measuring direction and the insertion axis. The performance of the approach was evaluated by dissecting and aligning 15 porcine cochlear specimens of which four were subsequently used for automated electrode insertions. RESULTS: The pose setting adapter could easily be integrated into an insertion force test setup. Its calculation and 3D printing was possible in all 15 cases. Compared to planning data, a mean positioning accuracy of 0.21 ± 0.10 mm at the level of the round window and a mean angular accuracy of 0.43° ± 0.21° were measured. After alignment, four specimens were used for electrode insertions, demonstrating the practical applicability of our method. CONCLUSION: In this work, we present a new method, which enables automated calculation and creation of a ready-to-print pose setting adapter for alignment of cochlear specimens in insertion test setups. The approach is characterized by a high level of accuracy and reproducibility in controlling the insertion trajectory. Therefore, it enables a higher degree of standardization in force measurement when performing ex vivo insertion tests and thereby improves reliability in electrode testing.

7.
Vaccine ; 39(51): 7357-7362, 2021 12 17.
Artigo em Inglês | MEDLINE | ID: mdl-34799142

RESUMO

Infectious diseases may cause serious morbidity and mortality in pregnant women, their foetuses, and infants; the risk associated with any newly emerging infectious disease (EID) is likely unknown at the time of its emergence. While the ongoing SARS-CoV-2 pandemic shows that the development of vaccines against new pathogens can be considerably accelerated, the immunization of pregnant women generally lags behind the general population. Guided by the priority pathogen list for WHO's R&D Blueprint for Action to Prevent Epidemics, this workshop sought to define the evidence needed for use of vaccines against EIDs in pregnant and lactating women, using Lassa fever as a model. Close to 60 maternal immunization (MI) and vaccine safety experts, regulators, vaccine developers, Lassa fever experts, and investigators from Lassa-affected countries examined the critical steps for vaccine development and immunization decisions for pregnant and lactating women. This paper reports on key themes and recommendations from the workshop. Current practice still assumes the exclusion of pregnant women from early vaccine trials. A shift in paradigm is needed to progress towards initial inclusion of pregnant women in Phase 2 and 3 trials. Several practical avenues were delineated. Participants agreed that vaccine platforms should be assessed early for their suitability for maternal immunization. It was noted that, in some cases, nonclinical data derived from assessing a given platform using other antigens may be adequate evidence to proceed to a first clinical evaluation and that concurrence from regulators may be sought with supporting rationale. For clinical trials, essential prerequisites such as documenting the disease burden in pregnant women, study site infrastructure, capabilities, and staff experience were noted. Early and sustained communication with the local community was considered paramount in any program for the conduct of MI trials and planned vaccine introduction.


Assuntos
COVID-19 , Doenças Transmissíveis Emergentes , Vacinas , Doenças Transmissíveis Emergentes/epidemiologia , Doenças Transmissíveis Emergentes/prevenção & controle , Feminino , Humanos , Lactação , Londres , Gravidez , Encaminhamento e Consulta , SARS-CoV-2 , Desenvolvimento de Vacinas
8.
N Engl J Med ; 385(2): 179-186, 2021 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-34161052

RESUMO

Viral variants of concern may emerge with dangerous resistance to the immunity generated by the current vaccines to prevent coronavirus disease 2019 (Covid-19). Moreover, if some variants of concern have increased transmissibility or virulence, the importance of efficient public health measures and vaccination programs will increase. The global response must be both timely and science based.


Assuntos
Vacinas contra COVID-19 , COVID-19/prevenção & controle , SARS-CoV-2 , COVID-19/transmissão , Vacinas contra COVID-19/imunologia , Humanos , Imunogenicidade da Vacina , Mutação , SARS-CoV-2/patogenicidade , Glicoproteína da Espícula de Coronavírus/genética , Virulência
9.
Clin Microbiol Infect ; 27(12): 1792-1798, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33813114

RESUMO

OBJECTIVES: This longitudinal case-control study aimed to determine the frequency of polymicrobial enteric detections in Ghanaian infants with and without diarrhoea. METHODS: Infants aged 1-12 months with and without diarrhoea attending the outpatient department of a peri-urban Ghanaian hospital were prospectively assessed and stool samples were collected on days 0, 6 and 28 and analysed for 18 enteric pathogens with PCR. RESULTS: At least one enteric pathogen was detected in 100 of 107 cases with diarrhoea (93%) and in 82 of 97 controls (85%). The number of pathogens was higher in cases than in controls (median three versus two pathogens, p 0.001). The adjusted attributable fraction (AF) for diarrhoea was highest for enterotoxigenic Escherichia coli (7.2%, 95% CI -2.0% to 16.3%), rotavirus (4.1%, 95% CI 0.6%-7.5%), Giardia lamblia (2.3%, 95% CI -0.7 to 5.3%) and astrovirus (2.3%, 95% CI -2.9 to 7.5%). In cases, a higher pathogen number was significantly associated with watery stool consistency (median 3, interquartile range (IQR) 2-5 versus median 2.5, IQR 1-4, p 0.014), stool frequency five or more per day (median 4, IQR 3-5 versus median 3, IQR 2-4, p 0.048) and vomiting (median 4, IQR 3-5 versus median 3, IQR 2-4, p 0.025). During follow-up, 94% (78/83) of cases and 85% (67/79) of controls had acquired at least one new pathogen without developing a new episode of diarrhoea. CONCLUSION: Enteric pathogens could be identified in the stool of the vast majority of Ghanaian infants, whereby pathogens were very frequently acquired without resulting in new episodes of diarrhoea during follow-up. A higher number of co-occurring pathogens may increase the risk of diarrhoea and disease severity.


Assuntos
Coinfecção , Diarreia , Estudos de Casos e Controles , Coinfecção/diagnóstico , Diarreia/epidemiologia , Escherichia coli Enterotoxigênica , Fezes , Gana/epidemiologia , Giardia lamblia , Humanos , Lactente , Rotavirus
10.
Vaccine ; 39(22): 3053-3066, 2021 05 21.
Artigo em Inglês | MEDLINE | ID: mdl-33637387

RESUMO

This is a Brighton Collaboration Case Definition of the term "Vaccine Associated Enhanced Disease" to be utilized in the evaluation of adverse events following immunization. The Case Definition was developed by a group of experts convened by the Coalition for Epidemic Preparedness Innovations (CEPI) in the context of active development of vaccines for SARS-CoV-2 vaccines and other emerging pathogens. The case definition format of the Brighton Collaboration was followed to develop a consensus definition and defined levels of certainty, after an exhaustive review of the literature and expert consultation. The document underwent peer review by the Brighton Collaboration Network and by selected Expert Reviewers prior to submission.


Assuntos
COVID-19 , Vacinas , Vacinas contra COVID-19 , Coleta de Dados , Humanos , Imunização/efeitos adversos , SARS-CoV-2 , Vacinas/efeitos adversos
13.
Vaccine ; 38(36): 5842-5850, 2020 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-32563606

RESUMO

INTRODUCTION: Acute norovirus gastroenteritis causes significant morbidity and in uncommon cases fatality in older adults. We investigated the safety and immunogenicity of bivalent virus-like particle (VLP) vaccine candidate formulations with and without monophosphoryl lipid A (adjuvant MPL) in this population. METHODS: In this phase II, double-blind, controlled trial 294 healthy adults, ≥ 60 years of age, were randomized (1:1:1:1) to four groups to receive one or two intramuscular immunizations 28 days apart, with 26 18-49 year-old controls who received one MPL-free dose. One-dose groups received placebo on Day 1. Vaccine formulations contained 15 µg GI.1 and 50 µg GII.4c VLP antigens and 500 µg Al(OH)3, with or without 15 µg MPL. We measured histo-blood group antigen blocking (HBGA) antibodies and ELISA Ig at Days 1, 8, 29, 57, 211 and 393, and avidity indices and cell-mediated immunity (CMI). Solicited local and systemic adverse events (AE) were assessed for 7 days and unsolicited AEs for 28 days after each injection. RESULTS: After one dose HBGA antibodies to both VLP antigens increased with similar kinetics and magnitude in all groups; geometric mean titres (GMTs) persisted above baseline through Day 393. GMTs were similar across age strata (18-49, 60-74, 75-84 and ≥ 85 years of age) and unaffected by a second vaccination or MPL. Total Ig showed similar responses. No clinically relevant differences or changes in avidity or CMI were observed between formulations. Both formulations were well tolerated with no vaccine-related SAEs, the most frequent AEs being mild injection site pain and fatigue. CONCLUSIONS: Adults over 60 years of age displayed no safety concerns and had similar immune responses to the norovirus VLP vaccine candidate as younger adults, unaffected by increasing age, a second dose or inclusion of MPL. This data supports the further development of the MPL-free vaccine candidate for older adults.


Assuntos
Gastroenterite , Norovirus , Vacinas de Partículas Semelhantes a Vírus , Idoso , Idoso de 80 Anos ou mais , Anticorpos Antivirais , Método Duplo-Cego , Humanos , Lipídeo A/análogos & derivados , Pessoa de Meia-Idade , Receptores de Trombopoetina
14.
Vaccine ; 38(33): 5313-5323, 2020 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-32563609

RESUMO

BACKGROUND: To increase the global supply of affordable IPV vaccine, preferably using Sabin viruses to comply with GAPIII requirements, Takeda has assessed three dosages of a stand-alone sIPV. METHODS: In this phase I/II study two cohorts of 40 adults and 60 toddlers, respectively, were initially assessed for safety after receiving high-dosage sIPV compared with placebo (adults) or Salk IPV (toddlers). A cohort of 240 infants was then enrolled and randomized (1:1:1:1) to receive low-, medium- or high-dosage sIPV, or a reference Salk IPV in a three-dose primary schedule at 6, 10 and 14 weeks of age. Parents completed safety diaries for 4 weeks after each dose, and immunogenicity was measured as neutralization antibody titers at baseline and four weeks after vaccination. RESULTS: All vaccinations were generally well-tolerated and sIPV had a comparable safety profile to the control arm in adults or the reference Salk IPV vaccine in toddlers and infants. Infants displayed dosage-dependent immune responses to sIPV when assayed using Sabin strains, which were equivalent to the reference IPV in the high-dosage sIPV group for serotypes 1 and 2, but not for Sabin and Salk serotype 3. Seroconversion rates (SCR) of the low- and medium-dosage groups were significantly lower than the Salk IPV group for both Sabin and Salk serotypes 1 and type 2 (p < 0.05), with no significant differences for Salk or Sabin serotypes 3. Responses to sIPV, particularly to Sabin types 1 and 2, were higher in initially seronegative infants, indicating possible interference by maternally-derived antibodies. CONCLUSIONS: A novel stand-alone Sabin-based IPV vaccine was well tolerated with an acceptable safety profile, but less immunogenic than reference Salk IPV at 6, 10 and 14 weeks of age for Salk serotypes 1 and 2, with apparent interference by maternal antibodies. Additional preclinical assessments will be made before any further clinical development.


Assuntos
Poliomielite , Poliovirus , Adulto , Anticorpos Antivirais , Humanos , Imunogenicidade da Vacina , Lactente , Poliomielite/prevenção & controle , Vacina Antipólio de Vírus Inativado/efeitos adversos , Vacina Antipólio Oral/efeitos adversos , Soroconversão
15.
Vaccine ; 38(31): 4783-4791, 2020 06 26.
Artigo em Inglês | MEDLINE | ID: mdl-32507409

RESUMO

A novel coronavirus (CoV), Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), emerged in late 2019 in Wuhan, China and has since spread as a global pandemic. Safe and effective vaccines are thus urgently needed to reduce the significant morbidity and mortality of Coronavirus Disease 2019 (COVID-19) disease and ease the major economic impact. There has been an unprecedented rapid response by vaccine developers with now over one hundred vaccine candidates in development and at least six having reached clinical trials. However, a major challenge during rapid development is to avoid safety issues both by thoughtful vaccine design and by thorough evaluation in a timely manner. A syndrome of "disease enhancement" has been reported in the past for a few viral vaccines where those immunized suffered increased severity or death when they later encountered the virus or were found to have an increased frequency of infection. Animal models allowed scientists to determine the underlying mechanism for the former in the case of Respiratory syncytial virus (RSV) vaccine and have been utilized to design and screen new RSV vaccine candidates. Because some Middle East respiratory syndrome (MERS) and SARS-CoV-1 vaccines have shown evidence of disease enhancement in some animal models, this is a particular concern for SARS-CoV-2 vaccines. To address this challenge, the Coalition for Epidemic Preparedness Innovations (CEPI) and the Brighton Collaboration (BC) Safety Platform for Emergency vACcines (SPEAC) convened a scientific working meeting on March 12 and 13, 2020 of experts in the field of vaccine immunology and coronaviruses to consider what vaccine designs could reduce safety concerns and how animal models and immunological assessments in early clinical trials can help to assess the risk. This report summarizes the evidence presented and provides considerations for safety assessment of COVID-19 vaccine candidates in accelerated vaccine development.


Assuntos
Anticorpos Antivirais/efeitos adversos , Anticorpos Antivirais/imunologia , Betacoronavirus/imunologia , Infecções por Coronavirus/imunologia , Pneumonia Viral/imunologia , Vacinas Virais/efeitos adversos , Vacinas Virais/imunologia , Animais , Betacoronavirus/patogenicidade , COVID-19 , Vacinas contra COVID-19 , Ensaios Clínicos como Assunto , Infecções por Coronavirus/prevenção & controle , Infecções por Coronavirus/virologia , Modelos Animais de Doenças , Humanos , Pandemias , Pneumonia Viral/virologia , Medição de Risco , SARS-CoV-2 , Síndrome Respiratória Aguda Grave/imunologia
16.
Travel Med Infect Dis ; 34: 101616, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32156630

RESUMO

BACKGROUND: In an initial study among children from non-Japanese encephalitis (JE)-endemic countries, seroprotection rates remained high 6 months after completion of the primary series with IXIARO®. METHODS: In this open-label follow-up study, a subset of 23 children who received a 2-dose primary series of IXIARO® in the parent study, were evaluated for safety and neutralizing antibody persistence for 36 months. RESULTS: Seroprotection rates (SPRs) remained high but declined from 100% one month after primary immunization to 91.3% at month 7 and 89.5% at month 36. Geometric mean titers (GMTs) declined considerably from 384.1 by day 56-60.8 at month 36. No long-term safety concerns were identified. CONCLUSIONS: The substantial decline in GMT observed in this study, together with previously published data on children vaccinated with IXIARO® support the recommendation for a booster dose in children who remain at risk of JE from 1 year after the primary series of IXIARO®, consistent with the recommendation for adults. CLINICAL TRIAL REGISTRY NUMBER: NCT01246479.


Assuntos
Anticorpos Neutralizantes/sangue , Vírus da Encefalite Japonesa (Espécie)/imunologia , Encefalite Japonesa/imunologia , Encefalite Japonesa/prevenção & controle , Vacinas contra Encefalite Japonesa/farmacologia , Adolescente , Anticorpos Antivirais/imunologia , Austrália , Criança , Pré-Escolar , Doenças Endêmicas , Europa (Continente) , Feminino , Seguimentos , Humanos , Masculino , Pediatria , Estados Unidos
18.
Artigo em Inglês | MEDLINE | ID: mdl-31776599

RESUMO

Today's world is characterized by increasing population density, human mobility, urbanization, and climate and ecological change. This global dynamic has various effects, including the increased appearance of emerging infectious diseases (EIDs), which pose a growing threat to global health security.Outbreaks of EIDs, like the 2013-2016 Ebola outbreak in West Africa or the current Ebola outbreak in Democratic Republic of the Congo (DRC), have not only put populations in low- and middle-income countries (LMIC) at risk in terms of morbidity and mortality, but they also have had a significant impact on economic growth in affected regions and beyond.The Coalition for Epidemic Preparedness Innovation (CEPI) is an innovative global partnership between public, private, philanthropic, and civil society organizations that was launched as the result of a consensus that a coordinated, international, and intergovernmental plan was needed to develop and deploy new vaccines to prevent future epidemics.CEPI is focusing on supporting candidate vaccines against the World Health Organization (WHO) Blueprint priority pathogens MERS-CoV, Nipah virus, Lassa fever virus, and Rift Valley fever virus, as well as Chikungunya virus, which is on the WHO watch list. The current vaccine portfolio contains a wide variety of technologies, ranging across recombinant viral vectors, nucleic acids, and recombinant proteins. To support and accelerate vaccine development, CEPI will also support science projects related to the development of biological standards and assays, animal models, epidemiological studies, and diagnostics, as well as build capacities for future clinical trials in risk-prone contexts.


Assuntos
Doenças Transmissíveis Emergentes , Epidemias , Vacinas , África Ocidental , Animais , Surtos de Doenças , Alemanha , Humanos
19.
Sci Rep ; 9(1): 18134, 2019 12 02.
Artigo em Inglês | MEDLINE | ID: mdl-31792345

RESUMO

The pathophysiology of malarial anemia is multifactorial and incompletely understood. We assessed mechanistic and risk factors for post-malarial anemia in Ghanaian and Gabonese children with severe P. falciparum malaria treated with parenteral artesunate followed by an oral artemisinin-combination therapy. We analyzed data from two independent studies in which children were followed on Days 7,14, and 28 after treatment with artesunate. Specific hematological parameters included the presence of hemoglobinopathies and erythropoietin. Presence of once-infected erythrocytes was assessed by flow cytometry in a sub-population. Of 143 children with a geometric mean parasitemia of 116,294/µL (95% CI: 95,574-141,505), 91 (88%) had anemia (Hb < 10 g/dL) at presentation. Hemoglobin increased after Day 7 correlating with increased erythropoiesis through adequate erythropoietin stimulation. 22 children (24%) remained anemic until Day 28. Post-artesunate delayed hemolysis was detected in 7 children (5%) with only minor differences in the dynamics of once-infected erythrocytes. Hyperparasitemia and hemoglobin at presentation were associated with anemia on Day 14. On Day 28 only lower hemoglobin at presentation was associated with anemia. Most children showed an adequate erythropoiesis and recovered from anemia within one month. Post-artesunate delayed hemolysis (PADH) and hyperparasitemia are associated with early malarial anemia and pre-existing anemia is the main determinant for prolonged anemia.


Assuntos
Anemia/induzido quimicamente , Antimaláricos/efeitos adversos , Artesunato/efeitos adversos , Malária/complicações , Malária/tratamento farmacológico , Anemia/terapia , Antimaláricos/administração & dosagem , Antimaláricos/uso terapêutico , Artesunato/administração & dosagem , Artesunato/uso terapêutico , Transfusão de Sangue , Criança , Pré-Escolar , Eritropoetina/sangue , Feminino , Humanos , Lactente , Infusões Parenterais , Masculino , Parasitemia/tratamento farmacológico
20.
J Infect Dis ; 220(4): 603-614, 2019 07 19.
Artigo em Inglês | MEDLINE | ID: mdl-31001633

RESUMO

BACKGROUND: We previously reported the tolerability and immunogenicity 1 month after intramuscular administration of 2 bivalent virus-like particle (VLP)-based candidate norovirus vaccine formulations in adults. We now describe the persistence of immunity and responses to a memory probe vaccination 1 year later. METHODS: A total of 454 healthy men and women aged 18-49 years in 3 equal groups received placebo (saline) or 15/50 or 50/50 vaccine formulations (ie, 15 or 50 µg of GI.1 genotype VLPs, respectively, and 50 µg of GII.4c VLPs) with MPL and Al(OH)3. Immunogenicity and safety were assessed up to day 365, when 351 participants received a memory probe vaccination of 15 µg each of GI.1 and GII.4c VLPs with Al(OH)3. RESULTS: No safety signals were detected up to 1 year after the first vaccination. Pan-immunoglobulin, immunoglobulin A, and histo-blood group antigen-blocking (HBGA) antibody levels among vaccinees waned but remained higher than levels before vaccination and levels in placebo recipients on days 180 and 365. Memory probe vaccination increased all antibody titers. Levels of HBGA antibodies to GI.1 but not GII.4c were higher after the first vaccination in candidate vaccine groups, compared with those in the placebo group. CONCLUSION: Levels of antibodies to both candidate norovirus VLP formulations persisted above baseline levels for at least 1 year after primary vaccination. HBGA-blocking responses to the memory probe for GI.1 but not GII.4c displayed characteristics of immune memory. CLINICAL TRIALS REGISTRATION: NCT02142504.


Assuntos
Antígenos de Grupos Sanguíneos , Infecções por Caliciviridae/prevenção & controle , Norovirus/imunologia , Vacinação , Vacinas de Partículas Semelhantes a Vírus/imunologia , Vacinas Virais/imunologia , Adolescente , Adulto , Infecções por Caliciviridae/sangue , Infecções por Caliciviridae/virologia , Método Duplo-Cego , Feminino , Humanos , Imunização Secundária , Imunogenicidade da Vacina , Masculino , Pessoa de Meia-Idade , Estados Unidos , Adulto Jovem
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