10 results on '"Visser, Leo G"'
Search Results
2. Identifying efficacious SARS-CoV-2 antivirals in a changing immune landscape.
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Visser, Leo G
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LANDSCAPE changes , *SARS-CoV-2 , *ANTIVIRAL agents - Published
- 2024
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3. Fractional dose yellow fever vaccination, coming of age.
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Roukens, Anna H E and Visser, Leo G
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YELLOW fever , *COMING of age , *VACCINATION - Published
- 2023
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4. A reference standard for urinary tract infection research: a multidisciplinary Delphi consensus study.
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Bilsen, Manu P, Conroy, Simon P, Schneeberger, Caroline, Platteel, Tamara N, van Nieuwkoop, Cees, Mody, Lona, Caterino, Jeffrey M, Geerlings, Suzanne E, Köves, Bela, Wagenlehner, Florian, Kunneman, Marleen, Visser, Leo G, and Lambregts, Merel M C
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URINARY tract infections , *DELPHI method , *INTERDISCIPLINARY research , *OLDER patients , *DRUG resistance in microorganisms - Abstract
The absence of a consensus-based reference standard for urinary tract infection (UTI) research adversely affects the internal and external validity of diagnostic and therapeutic studies. This omission hinders the accumulation of evidence for a disease that imposes a substantial burden on patients and society, particularly in an era of increasing antimicrobial resistance. We did a three-round Delphi study involving an international, multidisciplinary panel of UTI experts (n=46) and achieved a high degree of consensus (94%) on the final reference standard. New-onset dysuria, urinary frequency, and urinary urgency were considered major symptoms, and non-specific symptoms in older patients were not deemed indicative of UTI. The reference standard distinguishes between UTI with and without systemic involvement, abandoning the term complicated UTI. Moreover, different levels of pyuria were incorporated in the reference standard, encouraging quantification of pyuria in studies done in all health-care settings. The traditional bacteriuria threshold (105 colony-forming units per mL) was lowered to 104 colony-forming units per mL. This new reference standard can be used for UTI research across many patient populations and has the potential to increase homogeneity between studies. [ABSTRACT FROM AUTHOR]
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- 2024
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5. Boostability after single-visit pre-exposure prophylaxis with rabies vaccine: a randomised controlled non-inferiority trial.
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Overduin, Lisanne A, Koopman, Jan Pieter R, Prins, Corine, Verbeek-Menken, Petra H, De Pijper, Cornelis A, Eblé, Phaedra L, Heerink, Fiona, van Genderen, Perry J J, Grobusch, Martin P, and Visser, Leo G
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RABIES vaccines , *PRE-exposure prophylaxis , *RANDOMIZED controlled trials , *VIRAL antibodies , *RABIES virus - Abstract
After rabies pre-exposure prophylaxis (PrEP) vaccination, scarcely available rabies immunoglobulins are not required for post-exposure prophylaxis (PEP). However, PrEP is not sufficiently accessible as it is cost-intensive and time-intensive. This study investigates whether rabies PrEP schedules can be shortened to one visit, removing some of these barriers. In a block-randomised (2:2:2:1) controlled, multicentre non-inferiority trial, healthy adult travellers (aged 18–50 years and >50 years) were randomly assigned to (A) single-visit intramuscular (1·0 mL); (B) single-visit intradermal (0·2 mL); (C) standard two-visit intramuscular (1·0 mL; day 0 and 7) PrEP; or (D) no rabies vaccination. 6 months later, participants received simulated intramuscular rabies PEP (1·0 mL; day 0 and 3). Rabies virus neutralising antibody (RVNA) concentrations were measured repeatedly. The primary outcome was the fold increase in geometric mean RVNA concentrations between day 0 and 7 after simulated PEP for all participants. The two main comparisons of this primary outcome are between the standard two-visit schedule and the one-visit intramuscular schedule, and between the standard two-visit schedule and the one-visit intradermal schedule. The non-inferiority margin was 0·67. This study is registered with EudraCT, 2017-000089-31. Between May 16, 2018, and March 26, 2020, 288 healthy adult travellers were randomly assigned and 214 participants were evaluated for the primary outcome. Single-visit intramuscular rabies PrEP induced an anamnestic antibody response non-inferior compared with the two-visit intramuscular schedule; single-visit intradermal PrEP did not. The fold increases in the single-visit intramuscular and the single-visit intradermal schedule were 2·32 (95% CI [1·43–3·77]) and 1·11 (0·66–1·87) times as high as the fold increase in the standard schedule, respectively. No vaccine-related serious adverse events were observed. Adverse events related to vaccination were mostly mild. Single intramuscular rabies vaccination can effectively prime travellers (aged 18–50 years), and potentially other populations, and could replace current standard two-visit rabies vaccination as PrEP. ZonMW. For the Dutch translation of the abstract see Supplementary Materials section. [ABSTRACT FROM AUTHOR]
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- 2024
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6. Immunogenicity of bivalent omicron (BA.1) booster vaccination after different priming regimens in health-care workers in the Netherlands (SWITCH ON): results from the direct boost group of an open-label, multicentre, randomised controlled trial.
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Tan, Ngoc H, Geers, Daryl, Sablerolles, Roos S G, Rietdijk, Wim J R, Goorhuis, Abraham, Postma, Douwe F, Visser, Leo G, Bogers, Susanne, van Dijk, Laura L A, Gommers, Lennert, van Leeuwen, Leanne P M, Boerma, Annemarie, Nijhof, Sander H, van Dort, Karel A, Koopmans, Marion P G, Dalm, Virgil A S H, Lafeber, Melvin, Kootstra, Neeltje A, Huckriede, Anke L W, and van Baarle, Debbie
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BOOSTER vaccines , *RESEARCH & development , *SARS-CoV-2 Omicron variant , *IMMUNE response , *MEDICAL personnel , *SARS-CoV-2 - Abstract
Bivalent mRNA-based COVID-19 vaccines encoding the ancestral and omicron spike (S) protein were developed as a countermeasure against antigenically distinct SARS-CoV-2 variants. We aimed to assess the (variant-specific) immunogenicity and reactogenicity of mRNA-based bivalent omicron (BA.1) vaccines in individuals who were primed with adenovirus-based or mRNA-based vaccines encoding the ancestral spike protein. We analysed results of the direct boost group of the SWITCH ON study, an open-label, multicentre, randomised controlled trial. Health-care workers from four academic hospitals in the Netherlands aged 18–65 years who had completed a primary COVID-19 vaccination regimen and received one booster of an mRNA-based vaccine, given no later than 3 months previously, were eligible. Participants were randomly assigned (1:1) using computer software in block sizes of 16 and 24 to receive an omicron BA.1 bivalent booster straight away (direct boost group) or a bivalent omicron BA.5 booster, postponed for 90 days (postponed boost group), stratified by priming regimen. The BNT162b2 OMI BA.1 boost was given to participants younger than 45 years, and the mRNA-1273.214 boost was given to participants 45 years or older, as per Dutch guidelines. The direct boost group, whose results are presented here, were divided into four subgroups for analysis: (1) Ad26.COV2.S (Johnson & Johnson) prime and BNT162b2 OMI BA.1 (BioNTech–Pfizer) boost (Ad/P), (2) mRNA-based prime and BNT162b2 OMI BA.1 boost (mRNA/P), (3) Ad26.COV2.S prime and mRNA-1273.214 (Moderna) boost (Ad/M), and (4) mRNA-based prime and mRNA-1273.214 boost (mRNA/M). The primary outcome was fold change in S protein S1 subunit-specific IgG antibodies before and 28 days after booster vaccination. The primary outcome and safety were assessed in all participants except those who withdrew, had a SARS-CoV-2 breakthrough infection, or had a missing blood sample at day 0 or day 28. This trial is registered with ClinicalTrials.gov , NCT05471440. Between Sept 2 and Oct 4, 2022, 219 (50%) of 434 eligible participants were randomly assigned to the direct boost group; 187 participants were included in the primary analyses; exclusions were mainly due to SARS-CoV-2 infection between days 0 and 28. From the 187 included participants, 138 (74%) were female and 49 (26%) were male. 42 (22%) of 187 participants received Ad/P and 44 (24%) mRNA/P (those aged <45 years), and 45 (24%) had received Ad/M and 56 (30%) mRNA/M (those aged ≥45 years). S1-specific binding antibody concentrations increased 7 days after bivalent booster vaccination and remained stable over 28 days in all four subgroups (geometric mean ratio [GMR] between day 0 and day 28 was 1·15 [95% CI 1·12–1·19] for the Ad/P group, 1·17 [1·14–1·20] for the mRNA/P group, 1·20 [1·17–1·23] for the Ad/M group, and 1·16 [1·13–1·19] for the mRNA/M group). We observed no significant difference in the GMR between the Ad/P and mRNA/P groups (p=0·51). The GMR appeared to be higher in the Ad/M group than in the mRNA/M group, but was not significant (p=0·073). Most side-effects were mild to moderate in severity and resolved within 48 h in most individuals. Booster vaccination with mRNA-1273.214 or BNT162b2 OMI BA.1 in adult healthcare workers resulted in a rapid recall of humoral and cellular immune responses independent of the priming regimen. Monitoring of SARS-CoV-2 immunity at the population level, and simultaneously antigenic drift at the virus level, remains crucial to assess the necessity and timing of COVID-19 variant-specific booster vaccinations. The Netherlands Organization for Health Research and Development (ZonMw). [ABSTRACT FROM AUTHOR]
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- 2023
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7. Serological response to three alternative series of hepatitis B revaccination (Fendrix, Twinrix, and HBVaxPro-40) in healthy non-responders: a multicentre, open-label, randomised, controlled, superiority trial.
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Raven, Stijn F H, Hoebe, Christian J P A, Vossen, Ann C T M, Visser, Leo G, Hautvast, Jeannine L A, Roukens, Anna H E, and van Steenbergen, Jim E
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HEPATITIS B , *HEPATITIS B vaccines , *PUBLIC health , *HERPES zoster , *HEPATITIS B prevention , *RESEARCH , *IMMUNIZATION , *HEPATITIS A vaccines , *RESEARCH methodology , *EVALUATION research , *MEDICAL cooperation , *COMBINED vaccines , *COMPARATIVE studies , *RANDOMIZED controlled trials , *VIRAL antibodies , *STATISTICAL sampling - Abstract
Background: Serological non-response can be present after hepatitis B vaccination in healthy adults. We aimed to establish which of three revaccination regimens is most effective at inducing protective immunity METHODS: Healthy adults (aged 18-80 years) from 16 Dutch centres (13 public health services, two university hospitals, and one travel clinic) were included in this multicentre, parallel group, randomised, controlled, superiority trial. The inclusion criterion was vaccine non-response (hepatitis B surface antibody [anti-HBs] titre <10 IU/L) after a primary series with three doses of one type of recombinant vaccine against hepatitis B virus (either HBVaxPro-10 or Engerix-B at months 0, 1, and 6). Participants were individually randomly assigned (1:1:1:1) to a vaccination series of repeated initial vaccination (HBVaxPro 10 μg or Engerix-B 20 μg) as the control, or to Twinrix 20 μg, Fendrix 20 μg, or HBVaxPro 40 μg. We used a web-based randomisation programme, stratified by centre, with a block size of four. Participants and centres were unmasked to assignment after randomisation. Laboratory staff and investigators were masked to vaccine-group assignment. All revaccination schedules were identical, with intramuscular vaccinations at 0, 1, and 2 months. Anti-HBs was measured at 0, 1, 2, and 3 months. The primary outcome was the percentage of responders (anti-HBs titres ≥10 IU/L) at 3 months. Immunogenicity and safety analyses were based on an intention-to-vaccinate analysis, the immunogenicity analysis with last observation carried forward for missing data, and the Bonferroni and the Benjamini-Hochberg method were applied to correct for multiple testing. The trial was registered in the Dutch National Trial Register and inclusion has been stopped (identifier NL3011; EudraCT-number 2011-005627-40).Findings: The participants were recruited between Nov 1, 2012, and Sept 1, 2017. 480 participants were randomly assigned and included in intention-to-vaccinate analyses: 124 (26%) to control, 118 (25%) to Twinrix, 114 (24%) to HBVaxPro-40, and 124 (26%) to Fendrix. At month 3 the percentage of responders was 83 (67%) of 124 (95% CI 57·9-75·1 in the control group, 94 (80%) of the 118 (71·3-86·5) in the Twinrix group, 95 (83%) of 114 (75·2-89·7) in the HBVaxPro-40 group, and 108 (87%) of 124 (79·9-92·4) in the Fendrix group. Compared with the control group, the percentage of responders was superior for the HBVaxPro-40 group (adjusted difference 21·6% [95% CI 10·4-32·7], p=0·0204 [Bonferroni corrected p value]) and the Fendrix group (26·3% [15·4-37·3], p=0·0006), but not the Twinrix group (25·0% [13·0-37·0]; p=0·0846). One serious adverse event occurred (herpes zoster ophthalmicus) in the Fendrix group, which was not attributed to the vaccine.Interpretation: Revaccinating healthy non-responders with Fendrix or HBVaxPro-40 resulted in significantly higher proportions of responders and therefore indication for these vaccines should be expanded to enable revaccination of non-responders.Funding: National Institute for Public Health and the Environment. [ABSTRACT FROM AUTHOR]- Published
- 2020
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8. Acute liver failure, multiorgan failure, cerebral oedema, and activation of proangiogenic and antiangiogenic factors in a case of Marburg haemorrhagic fever
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van Paassen, Judith, Bauer, Martijn P, Arbous, M Sesmu, Visser, Leo G, Schmidt-Chanasit, Jonas, Schilling, Stefan, Ölschläger, Stephan, Rieger, Toni, Emmerich, Petra, Schmetz, Christel, van de Berkmortel, Franchette, van Hoek, Bart, van Burgel, Nathalie D, Osterhaus, Albert D, Vossen, Ann CTM, Günther, Stephan, and van Dissel, Jaap T
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MULTIPLE organ failure , *LIVER failure , *ACUTE diseases , *CEREBRAL circulation , *EDEMA , *NEOVASCULARIZATION , *CASE studies , *HEMORRHAGIC diseases - Abstract
Summary: A woman developed Marburg haemorrhagic fever in the Netherlands, most likely as a consequence of being exposed to virus-infected bats in the python cave in Maramagambo Forest during a visit to Uganda. The clinical syndrome was dominated by acute liver failure with secondary coagulopathy, followed by a severe systemic inflammatory response, multiorgan failure, and fatal cerebral oedema. A high blood viral load persisted during the course of the disease. The initial systemic inflammatory response coincided with peaks in interferon-γ and tumour necrosis factor-α concentrations in the blood. A terminal rise in interleukin-6, placental growth factor (PlGF), and soluble vascular endothelial growth factor receptor-1 (sVEGF-R1) seemed to suggest an advanced pathophysiological stage of Marburg haemorrhagic fever associated with vascular endothelial dysfunction and fatal cerebral oedema. The excess of circulating sVEGF-R1 and the high sVEGF-R1:PlGF ratio shortly before death resemble pathophysiological changes thought to play a causative part in pre-eclampsia. Aggressive critical-care treatment with renal replacement therapy and use of the molecular absorbent recirculation system appeared able to stabilise—at least temporarily—the patient''s condition. [Copyright &y& Elsevier]
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- 2012
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9. Improving clinical management of patients with severe yellow fever.
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Wilder-Smith, Annelies, Chen, Lin H, Melo, Adelino, and Visser, Leo G
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YELLOW fever , *WEST Nile fever , *JAPANESE B encephalitis , *FLAVIVIRAL diseases - Published
- 2019
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10. A recurrent migratory swelling.
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Roach, Rachel E J, van Doorn, Remco, de Bruïne, Francisca T, Arend, Sandra M, Visser, Leo G, and de Bruïne, Francisca T
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SIALADENITIS , *EDEMA , *ANTIHISTAMINES , *DRUG dosage , *ULTRASONIC imaging , *DIAGNOSIS , *THERAPEUTICS , *MACROLIDE antibiotics , *ANTIPARASITIC agents , *ANIMALS , *FISHES , *RAW foods , *DISEASE relapse , *TREATMENT effectiveness , *SPIRURIDA diseases - Published
- 2018
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