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Featured researches published by L Kaiser.


The New England Journal of Medicine | 2016

Phase 1 Trials of rVSV Ebola Vaccine in Africa and Europe.

Angela Huttner; Patricia Njuguna; Christine Dahlke; Sabine Yerly; V. Kraehling; Rahel Kasonta; Marcus Altfeld; Floriane Auderset; Nadine Biedenkopf; S. Borregaard; R. Burrow; Christophe Combescure; Jules Alexandre Desmeules; Markus Eickmann; Axel Finckh; Jay W. Hooper; A. Jambrecina; Kabwende Al; Gürkan Kaya; Domtila Kimani; Bertrand Lell; Barbara Lemaître; Marguerite Massinga-Loembe; Alain Matthey; A. Nolting; Caroline Ogwang; Michael Ramharter; Jonas Schmidt-Chanasit; Stefan Schmiedel; Peter Silvera

BACKGROUND The replication-competent recombinant vesicular stomatitis virus (rVSV)-based vaccine expressing a Zaire ebolavirus (ZEBOV) glycoprotein was selected for rapid safety and immunogenicity testing before its use in West Africa. METHODS We performed three open-label, dose-escalation phase 1 trials and one randomized, double-blind, controlled phase 1 trial to assess the safety, side-effect profile, and immunogenicity of rVSV-ZEBOV at various doses in 158 healthy adults in Europe and Africa. All participants were injected with doses of vaccine ranging from 300,000 to 50 million plaque-forming units (PFU) or placebo. RESULTS No serious vaccine-related adverse events were reported. Mild-to-moderate early-onset reactogenicity was frequent but transient (median, 1 day). Fever was observed in up to 30% of vaccinees. Vaccine viremia was detected within 3 days in 123 of the 130 participants (95%) receiving 3 million PFU or more; rVSV was not detected in saliva or urine. In the second week after injection, arthritis affecting one to four joints developed in 11 of 51 participants (22%) in Geneva, with pain lasting a median of 8 days (interquartile range, 4 to 87); 2 self-limited cases occurred in 60 participants (3%) in Hamburg, Germany, and Kilifi, Kenya. The virus was identified in one synovial-fluid aspirate and in skin vesicles of 2 other vaccinees, showing peripheral viral replication in the second week after immunization. ZEBOV-glycoprotein-specific antibody responses were detected in all the participants, with similar glycoprotein-binding antibody titers but significantly higher neutralizing antibody titers at higher doses. Glycoprotein-binding antibody titers were sustained through 180 days in all participants. CONCLUSIONS In these studies, rVSV-ZEBOV was reactogenic but immunogenic after a single dose and warrants further evaluation for safety and efficacy. (Funded by the Wellcome Trust and others; ClinicalTrials.gov numbers, NCT02283099, NCT02287480, and NCT02296983; Pan African Clinical Trials Registry number, PACTR201411000919191.).


Lancet Infectious Diseases | 2015

The effect of dose on the safety and immunogenicity of the VSV Ebola candidate vaccine: a randomised double-blind, placebo-controlled phase 1/2 trial

Angela Huttner; Julie-Anne Dayer; Sabine Yerly; Christophe Combescure; Floriane Auderset; Jules Alexandre Desmeules; Markus Eickmann; Axel Finckh; Ana Rita Goncalves; Jay W. Hooper; Gürkan Kaya; Verena Krähling; Steve A. Kwilas; Barbara Lemaître; Alain Matthey; Peter Silvera; Stephan Becker; Patricia Fast; Vasee S. Moorthy; Marie Paule Kieny; L Kaiser; Claire-Anne Siegrist

BACKGROUND Safe and effective vaccines against Ebola could prevent or control outbreaks. The safe use of replication-competent vaccines requires a careful dose-selection process. We report the first safety and immunogenicity results in volunteers receiving 3 × 10(5) plaque-forming units (pfu) of the recombinant vesicular stomatitis virus-based candidate vaccine expressing the Zaire Ebola virus glycoprotein (rVSV-ZEBOV; low-dose vaccinees) compared with 59 volunteers who had received 1 ×10(7) pfu (n=35) or 5 × 10(7) pfu (n=16) of rVSV-ZEBOV (high-dose vaccinees) or placebo (n=8) before a safety-driven study hold. METHODS The Geneva rVSV-ZEBOV study, an investigator-initiated phase 1/2, dose-finding, placebo-controlled, double-blind trial conducted at the University Hospitals of Geneva, Switzerland, enrolled non-pregnant, immunocompetent, and otherwise healthy adults aged 18-65 years. Participants from the low-dose group with no plans to deploy to Ebola-aff5cted regions (non-deployable) were randomised 9:1 in a double-blind fashion using randomly permuted blocks of varying sizes to a single injection of 3 × 10(5) pfu or placebo, whereas deployable participants received single-injection 3 × 10(5) pfu open-label. Primary safety and immunogenicity outcomes were the incidence of adverse events within 14 days of vaccination and day-28 antibody titres, respectively, analysed by intention to treat. After viral oligoarthritis was observed in 11 of the first 51 vaccinees (22%) receiving 10(7) or 5 × 10(7) pfu, 56 participants were given a lower dose (3 × 10(5) pfu, n=51) or placebo (n=5) to assess the effect of dose reduction on safety and immunogenicity. This trial is ongoing with a follow-up period of 12 months; all reported results are from interim databases. This study is registered with ClinicalTrials.gov, number NCT02287480. FINDINGS Between Jan 5 and Jan 26, 2015, 43 non-deployable participants received low-dose rVSV-ZEBOV (3 × 10(5) pfu) or placebo in a double-blind fashion, whereas 13 deployable participants received 3 × 10(5) pfu open-label. Altogether, in the low-dose group, 51 participants received rVSV-ZEBOV and five received placebo. No serious adverse events occurred. At 3 × 10(5) pfu, early-onset reactogenicity remained frequent (45 [88%] of 51 compared with 50 [98%] of 51 high dose and two [15%] of 13 placebo recipients), but mild. Objective fever was present in one (2%) of 51 low-dose versus 13 (25%) of 51 high-dose vaccinees receiving at least 1 ×10(7) pfu (p<0·0001). Subjective fever (p<0·0001), myalgia (p=0·036), and chills (p=0·026) were significantly reduced and their time of onset delayed, reflecting significantly lower viraemia (p<0·0001) and blood monocyte-activation patterns (p=0·0233). Although seropositivity rates remained similarly high (48 [94%] of 51), day-28 EBOV-glycoprotein-binding and neutralising antibody titres were lower in low-dose versus high-dose vaccinees (geometric mean titres 344·5 [95% CI 229·7-516·4] vs 1064·2 [757·6-1495·1]; p<0·0001; and 35·1 [24·7-50·7] vs 127·0 [86·0-187·6]; p<0·0001, respectively). Furthermore, oligoarthritis again occurred on day 10 (median; IQR 9-14) in 13 (25%) of 51 low-dose vaccinees, with maculopapular, vesicular dermatitis, or both in seven (54%) of 13; arthritis was associated with increasing age in low-dose but not high-dose vaccinees. Two vaccinees presented with purpura of the lower legs; histological findings indicated cutaneous vasculitis. The presence of rVSV in synovial fluid and skin lesions confirmed causality. INTERPRETATION Reducing the dose of rVSV-ZEBOV improved its early tolerability but lowered antibody responses and did not prevent vaccine-induced arthritis, dermatitis, or vasculitis. Like its efficacy, the safety of rVSV-ZEBOV requires further definition in the target populations of Africa. FUNDING Wellcome Trust through WHO.


Clinical Infectious Diseases | 2014

Treatment-Naive Individuals Are the Major Source of Transmitted HIV-1 Drug Resistance in Men Who Have Sex With Men in the Swiss HIV Cohort Study

Sara M. Drescher; Viktor von Wyl; Wan-Lin Yang; Jürg Böni; Sabine Yerly; Cyril Shah; Vincent Aubert; Thomas Klimkait; Patrick Taffé; Hansjakob Furrer; Manuel Battegay; Juan Ambrosioni; Matthias Cavassini; Enos Bernasconi; Pietro Vernazza; Bruno Ledergerber; Huldrych F. Günthard; Roger D. Kouyos; V. Aubert; J. Barth; M. Battegay; E Bernasconi; J Böni; H C Bucher; C. Burton-Jeangros; A Calmy; Matthias Egger; L Elzi; Jan Fehr; Jacques Fellay

BACKGROUND Human immunodeficiency virus type 1 (HIV-1) transmitted drug resistance (TDR) can compromise antiretroviral therapy (ART) and thus represents an important public health concern. Typically, sources of TDR remain unknown, but they can be characterized with molecular epidemiologic approaches. We used the highly representative Swiss HIV Cohort Study (SHCS) and linked drug resistance database (SHCS-DRDB) to analyze sources of TDR. METHODS ART-naive men who have sex with men with infection date estimates between 1996 and 2009 were chosen for surveillance of TDR in HIV-1 subtype B (N = 1674), as the SHCS-DRDB contains pre-ART genotypic resistance tests for >69% of this surveillance population. A phylogeny was inferred using pol sequences from surveillance patients and all subtype B sequences from the SHCS-DRDB (6934 additional patients). Potential sources of TDR were identified based on phylogenetic clustering, shared resistance mutations, genetic distance, and estimated infection dates. RESULTS One hundred forty of 1674 (8.4%) surveillance patients carried virus with TDR; 86 of 140 (61.4%) were assigned to clusters. Potential sources of TDR were found for 50 of 86 (58.1%) of these patients. ART-naive patients constitute 56 of 66 (84.8%) potential sources and were significantly overrepresented among sources (odds ratio, 6.43 [95% confidence interval, 3.22-12.82]; P < .001). Particularly large transmission clusters were observed for the L90M mutation, and the spread of L90M continued even after the near cessation of antiretroviral use selecting for that mutation. Three clusters showed evidence of reversion of K103N or T215Y/F. CONCLUSIONS Many individuals harboring viral TDR belonged to transmission clusters with other Swiss patients, indicating substantial domestic transmission of TDR in Switzerland. Most TDR in clusters could be linked to sources, indicating good surveillance of TDR in the SHCS-DRDB. Most TDR sources were ART naive. This, and the presence of long TDR transmission chains, suggests that resistance mutations are frequently transmitted among untreated individuals, highlighting the importance of early diagnosis and treatment.


Hiv Medicine | 2009

Liver enzyme elevation after lamivudine withdrawal in HIV–hepatitis B virus co‐infected patients: the Swiss HIV Cohort Study

C. Bellini; Olivia Keiser; J-P Chave; J‐M Evison; Jan Fehr; L Kaiser; Rainer Weber; P. Vernazza; Enos Bernasconi; Amalio Telenti; Matthias Cavassini

The principal causes of liver enzyme elevation among HIV–hepatitis B virus (HBV) co‐infected patients are the hepatotoxic effects of antiretroviral therapy (ART), alcohol abuse, ART‐induced immune reconstitution and the exacerbation of chronic HBV infection.


Clinical Infectious Diseases | 2010

Upper and Lower Respiratory Tract Viral Infections and Acute Graft Rejection in Lung Transplant Recipients

Paola M. Soccal; John-David Aubert; Pierre-Olivier Bridevaux; Jorge Garbino; Yves Thomas; Thierry Rochat; Pascal Meylan; Caroline Tapparel; L Kaiser

Abstract Background. Lung transplant recipients are frequently exposed to respiratory viruses and are particularly at risk for severe complications. The aim of this study was to assess the association among the presence of a respiratory virus detected by molecular assays in bronchoalveolar lavage (BAL) fluid, respiratory symptoms, and acute rejection in adult lung transplant recipients. Methods. Upper (nasopharyngeal swab) and lower (BAL) respiratory tract specimens from 77 lung transplant recipients enrolled in a cohort study and undergoing bronchoscopy with BAL and transbronchial biopsies were screened using 17 different polymerase chain reaction—based assays. Results. BAL fluid and biopsy specimens from 343 bronchoscopic procedures performed in 77 patients were analyzed. We also compared paired nasopharyngeal and BAL fluid specimens collected in a subgroup of 283 cases. The overall viral positivity rate was 29.3% in the upper respiratory tract specimens and 17.2% in the BAL samples (P < .001). We observed a significant association between the presence of respiratory symptoms and positive viral detection in the lower respiratory tract (P = .012). Conversely, acute rejection was not associated with the presence of viral infection (odds ratio, 0.41; 95% confidence interval, 0.20–0.88). The recovery of lung function was significantly slower when acute rejection and viral infection were both present. Conclusions. A temporal relationship exists between acute respiratory symptoms and positive viral nucleic acid detection in BAL fluid from lung transplant recipients. We provide evidence suggesting that respiratory viruses are not associated with acute graft rejection during the acute phase of infection.


Journal of Hepatology | 2013

Comparative genetic analyses point to HCP5 as susceptibility locus for HCV-associated hepatocellular carcinoma

Christian Lange; Stéphanie Bibert; Jean-François Dufour; Cristina Cellerai; Andreas Cerny; Markus H. Heim; L Kaiser; Raffaele Malinverni; Beat Müllhaupt; Francesco Negro; David Semela; Darius Moradpour; Zoltán Kutalik; Pierre-Yves Bochud

BACKGROUND & AIMS Recently, genetic variations in MICA (lead single nucleotide polymorphism [SNP] rs2596542) were identified by a genome-wide association study (GWAS) to be associated with hepatitis C virus (HCV)-related hepatocellular carcinoma (HCC) in Japanese patients. In the present study, we sought to determine whether this SNP is predictive of HCC development in the Caucasian population as well. METHODS An extended region around rs2596542 was genotyped in 1924 HCV-infected patients from the Swiss Hepatitis C Cohort Study (SCCS). Pair-wise correlation between key SNPs was calculated both in the Japanese and European populations (HapMap3: CEU and JPT). RESULTS To our surprise, the minor allele A of rs2596542 in proximity of MICA appeared to have a protective impact on HCC development in Caucasians, which represents an inverse association as compared to the one observed in the Japanese population. Detailed fine-mapping analyses revealed a new SNP in HCP5 (rs2244546) upstream of MICA as strong predictor of HCV-related HCC in the SCCS (univariable p=0.027; multivariable p=0.0002, odds ratio=3.96, 95% confidence interval=1.90-8.27). This newly identified SNP had a similarly directed effect on HCC in both Caucasian and Japanese populations, suggesting that rs2244546 may better tag a putative true variant than the originally identified SNPs. CONCLUSIONS Our data confirms the MICA/HCP5 region as susceptibility locus for HCV-related HCC and identifies rs2244546 in HCP5 as a novel tagging SNP. In addition, our data exemplify the need for conducting meta-analyses of cohorts of different ethnicities in order to fine map GWAS signals.


Antiviral Therapy | 2012

Responses of solid organ transplant recipients to the AS03-adjuvanted pandemic influenza vaccine.

Claire-Anne Siegrist; Juan Ambrosioni; Michael Bel; Christophe Combescure; Karine Hadaya; Pierre-Yves Martin; Paola M. Soccal; Thierry Berney; Stéphane Noble; Sara Meier; Klara M. Posfay-Barbe; Stéphane Grillet; L Kaiser; van Delden C

BACKGROUND Solid organ transplant (SOT) recipients are a priority group for influenza vaccination and strategies enhancing immunogenicity are needed. METHODS We determined adverse reactions, changes in biomarkers of graft function and immune responses to two doses of the AS03-adjuvanted influenza A/09/H1N1 vaccine in 216 SOT recipients and in 138 controls after one dose. Antibody responses were measured by haemagglutination inhibition and confirmed by microneutralization. We calculated geometric mean titres (GMT) and seroprotection rates (GMT≥40). RESULTS Adverse reactions were fewer than in controls and graft function remained unaffected. Seroprotection was achieved by only 70.3% of SOT recipients, with significant differences between groups (lung 43.6%, heart 72.0%, kidney 83.3%, liver 83.3% and pancreas 85%), compared to 87% of controls (P<0.001). The weakest responses (seroprotection 43.5%) were elicited in lung transplant recipients. GMT remained threefold lower (115 versus 340) in SOT recipients than controls. Multivariate analyses identified increasing age, type of transplant and increasing blood levels of mycophenolate as independently associated to weaker responses. In contrast, even high blood levels of calcineurin inhibitors remained without significant influence on vaccine responses. CONCLUSIONS The squalene-based adjuvanted A/09/H1N1 vaccine was safe in SOT recipients. However, even two doses of this adjuvanted influenza vaccine did not provide adequate protection for lung transplant recipients and those with high mycophenolate blood levels. Additional prophylactic measures should, therefore, be considered for these high-risk groups.


Hiv Medicine | 2011

Clinical relevance of cytomegalovirus viraemia(

E Boffi El Amari; Christophe Combescure; Sabine Yerly; Alexandra Calmy; L Kaiser; Barbara Hasse; Hansjakob Furrer; Matthias Cavassini; Pietro Vernazza; Hans H. Hirsch; Enos Bernasconi; Bernard Hirschel

Using new sensitive quantitative polymerase chain reaction (PCR) assays, cytomegalovirus (CMV) DNA is often detectable in the plasma of immunosuppressed patients. We investigated the prognostic value of a positive CMV DNA test for the development of CMV end‐organ disease, other AIDS‐defining events and mortality.


International Journal of Cancer | 2014

Comprehensive metagenomic analysis of glioblastoma reveals absence of known virus despite antiviral‐like type I interferon gene response

Erika Cosset; Tom J. Petty; Val erie Dutoit; Samuel Cordey; Ismael Padioleau; Patricia Otten-Hernandez; Laurent Farinelli; L Kaiser; Pascale Bruyère-Cerdan; Diderik Tirefort; Soraya Amar El-Dusouqui; Zeynab Nayernia; Karl-Heinz Krause; Evgeny M. Zdobnov; Pierre-Yves Dietrich; Emmanuel Rigal; Olivier Preynat-Seauve

Glioblastoma is a deadly malignant brain tumor and one of the most incurable forms of cancer in need of new therapeutic targets. As some cancers are known to be caused by a virus, the discovery of viruses could open the possibility to treat, and perhaps prevent, such a disease. Although an association with viruses such as cytomegalovirus or Simian virus 40 has been strongly suggested, involvement of these and other viruses in the initiation and/or propagation of glioblastoma remains vague, controversial and warrants elucidation. To exhaustively address the association of virus and glioblastoma, we developed and validated a robust metagenomic approach to analyze patient biopsies via high‐throughput sequencing, a sensitive tool for virus screening. In addition to traditional clinical diagnostics, glioblastoma biopsies were deep‐sequenced and analyzed with a multistage computational pipeline to identify known or potentially discover unknown viruses. In contrast to the studies reporting the presence of viral signatures in glioblastoma, no common or recurring active viruses were detected, despite finding an antiviral‐like type I interferon response in some specimens. Our findings highlight a discrete and non‐specific viral signature and uncharacterized short RNA sequences in glioblastoma. This study provides new insights into glioblastoma pathogenesis and defines a general methodology that can be used for high‐resolution virus screening and discovery in human cancers.


Bone Marrow Transplantation | 2012

Clinical features and outcome of 2009-influenza A (H1N1) after allogeneic hematopoietic SCT

Bilal Mohty; Y Thomas; Marija Vukicevic; M Nagy; Emmanuel Levrat; Michael Bernimoulin; L Kaiser; Eddy Roosnek; Jakob Passweg; Yves Chalandon

The impact of the 2009 H1N1-Influenza A (H1N1) pandemic in allogeneic hematopoietic SCT recipients (allo-HSCT) is not yet well defined. Between May 2009 and May 2010, all allo-HSCTs who presented with respiratory symptoms were screened for the presence of the H1N1 virus. Oseltamivir resistance was assessed and chart reviews were performed for all cases. In all, 51 of 248 (20%) allo-HSCT recipients followed at our outpatient clinic were screened. We identified 10 patients with H1N1 infection. Close contact with children was the most commonly suspected mode of transmission. Upper and lower respiratory tract infections were present in eight and five patients, respectively. Lymphopenia (<1 G/L) was the most frequent biological abnormality. High immunosuppression was responsible for severe infection requiring mechanical ventilation associated with prolonged viral shedding in three patients who had significant comorbidities and GvHD. Two of them developed an oseltamivir-resistant strain and both patients died subsequently despite intensive therapy, resulting in a case fatality rate of 20%. In conclusion, although most allo-HSCTs had mild symptoms from H1N1 infection, severe immunosuppression and emergence of oseltamivir resistance were likely responsible for a substantial morbidity, further supporting the need for vaccination and monitoring of close contacts, especially children.

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A Calmy

St. Vincent's Health System

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L Elzi

University of Lausanne

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H C Bucher

Kantonsspital St. Gallen

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Jan Fehr

University of Zurich

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