Isabel Leroux-Roels

• MD, PhD
• Ghent University

We estimated the effectiveness of the adapted monovalent XBB.1.5 COVID‐19 vaccines against PCR‐confirmed SARS‐CoV‐2 hospitalisation during the BA.2.86/JN.1 lineage‐predominant period using a multicentre test‐negative case–control study in Europe. We included older adults (≥ 65 years) hospitalised with severe acute respiratory infection from Novembe...

Introduction. Cervarix and Gardasil are two HPV vaccines with differing antigen and adjuvant compositions. Gardasil-4 contains HPV types 6, 11, 16 and 18 type-specific L1 viral like particles (VLPs) formulated with amorphous AlHO9PS-3 adjuvant, while Cervarix targets HPV types 16 and 18 using AS04 (Al(OH)3 + TLR4 agonist MPL) to enhance immune resp...

Background In a phase 3 study, the approved RSVPreF3 OA vaccine, administered as a single dose in adults aged ≥ 60 years, has demonstrated high efficacy against RSV disease and was well tolerated with a favorable safety profile. Here we present immunogenicity results in older adults of different age and frailty status from the same study. Methods...

Background/Objectives: In a Phase 2a, double-blind, placebo-controlled study including healthy participants aged 18–55 years, OVX836, a nucleoprotein (NP)-based candidate vaccine, previously showed a good safety profile, a robust immune response (both humoral and cellular) and a preliminary signal of protection (VE = 84%) against PCR-confirmed symp...

Background This study investigated the safety, reactogenicity, and immunogenicity in healthy subjects of a Clostridioides difficile vaccine candidate with/without adjuvant, targeting toxins A and B. Methods In this first-in-human, phase 1, observer-blind study, subjects aged 18–45 years were randomized to receive F2 antigen (n = 10) or placebo (n...

Seasonal influenza vaccine effectiveness is low. Carbohydrate fatty acid monosulphate ester (CMS), a new oil-in-water adjuvant, has proven potency in animal models with suggested capacity for dose-sparing. The objective was to evaluate safety and immunogenicity of CMS when added to a low-dose influenza vaccine (QIV) in humans. In a randomised, doub...

Background Despite the many guidelines for reprocessing of medical instruments, challenges persist such as microbial resistance to biocides, corrosive effects on materials, and time-consuming reprocessing procedures. Ultraviolet (UV) C light-emitting diode (LED) chambers might provide a solution but the integration in healthcare is still in its inf...

Background We report data from Stage 1 of an ongoing two-staged, phase I/II randomized clinical trial (NCT05073003) with a 4-component Generalized Modules for Membrane Antigens-based vaccine against Shigella sonnei and S. flexneri 1b, 2a and 3a (altSonflex1-2-3, GSK). Methods 18–50-year-old Europeans (N=102) were randomized (2:1) to receive two in...

Background Colistin serves as the last line of defense against multidrug resistant Gram-negative bacterial infections in both human and veterinary medicine. This study aimed to investigate the occurrence and spread of colistin-resistant Enterobacterales (ColR-E) using a One Health approach in Belgium and in the Netherlands. Methods In a transnatio...

Background Day care centres (DCCs) are ideal settings for drug-resistant bacteria to emerge. Prevalence numbers of faecal carriage of antimicrobial resistant bacteria in these settings are rare. We aimed to determine the prevalence of faecal antimicrobial resistant bacteria carriage in children attending DCCs and to assess and identify infection ri...

Background The adjuvanted RSV prefusion F protein-based vaccine (RSVPreF3 OA) was efficacious against RSV-related lower respiratory tract disease (RSV-LRTD) in ≥60-year-olds over 1 RSV season. We evaluated efficacy and safety of 1 RSVPreF3 OA dose and of 2 RSVPreF3 OA doses given 1 year apart against RSV-LRTD over 2 RSV seasons post-dose 1. Method...

Background Respiratory syncytial virus (RSV) fusion protein stabilized in the prefusion conformation (RSVPreF3) was under investigation as a maternal vaccine. Methods This phase 2, randomized, placebo-controlled, single-dose, multicenter study enrolled healthy, non-pregnant women, randomized 1:1:1:1:1 to five parallel groups studying RSVPreF3 (60...

Background RSVPreF3 OA was recently approved by the United States FDA for the prevention of RSV-related lower respiratory tract disease (RSV-LRTD) in adults ≥ 60 years of age (YOA). We present persistence of vaccine efficacy (VE) of a single RSVPreF3 OA dose, along with VE and safety of annual revaccination dose, over 2 RSV seasons. Methods In thi...

This study aimed to map MDRO carriage and potential transmission within and between three Flemish tertiary care hospitals and their neighbouring nursing homes. A cross-sectional MDRO prevalence survey was organized between October 2017 and February 2019. Perianal swabs were cultured for detection of MDRO. Determination of clonal relatedness based o...

Background Older adults with chronic cardiorespiratory or endocrine/metabolic conditions are at increased risk of respiratory syncytial virus (RSV)-related acute respiratory illness (RSV-ARI) and severe respiratory disease. In an ongoing, randomized, placebo-controlled, multicountry, phase 3 trial in ≥60-year-old participants, an AS01E-adjuvanted R...

Background: In the previous (parent) study, 2 doses of different formulations of an investigational vaccine against respiratory syncytial virus (RSVPreF3 OA) were well tolerated and immunogenic in older adults. This multicenter phase 2b extension study assessed safety and immunogenicity of a revaccination (third) dose of the 120 μg RSVPreF3-AS01E...

Background: OVX836, a recombinant vaccine containing the nucleoprotein of the influenza A virus A/WSN/1933 (H1N1) and the oligomerisation domain OVX313, has displayed a good safety profile and elicited dose-dependent humoral and cellular immune responses at 90 μg or 180 μg (intramuscularly) in previous clinical trials. The aim of this study was to...

The development of an efficacious vaccine against norovirus is of paramount importance given its potential to reduce the global burden of norovirus-associated morbidity and mortality. Here, we report a detailed immunological analysis of a phase I, double-blind, placebo-controlled clinical trial performed on 60 healthy adults, ages 18 to 40. Total s...

Background Accumulating evidence shows a role of the hospital wastewater system in the spread of multidrug-resistant organisms, such as carbapenemase producing Enterobacterales (CPE). Several sequential outbreaks of CPE on the geriatric ward of the Ghent University hospital have led to an outbreak investigation. Focusing on OXA-48 producing Citroba...

Lay Summary Respiratory syncytial virus (RSV) causes respiratory illnesses, which can lead to serious complications in older adults. We estimated how common infections due to RSV are in adults living in the community or long-term care facilities. For 2 years, we followed approximately 2000 adults 50 years and older in Europe and the United States....

Background: Respiratory syncytial virus (RSV) is an important cause of acute respiratory infection, lower respiratory tract disease, clinical complications, and death in older adults. There is currently no licensed vaccine against RSV infection. Methods: In an ongoing, international, placebo-controlled, phase 3 trial, we randomly assigned, in a...

Background: V-306 is a virus-like particle-based vaccine candidate displaying respiratory syncytial virus (RSV) F site II protein mimetics (FsIIm) as an antigenic epitope. Methods: This was a randomized, placebo-controlled, double-blind, dose-escalating, first-in-human study, conducted in 60 women aged 18-45 years. Twenty subjects per cohort (15...

Influenza A viruses (IAVs) of subtype H3 that infect humans are antigenically divergent from those of birds, horses, and swine. Human immunity against these viruses might be limited, implying potential pandemic risk. To determine human risk, we selected 4 avian, 1 equine, and 3 swine IAVs representing major H3 lineages. We tested serum collected du...

Background RSV-associated acute respiratory infections (ARI), particularly lower respiratory tract diseases (LRTD), present a significant disease burden in older adults. Currently, there are no approved vaccines against RSV. We present results from an ongoing study designed to demonstrate the vaccine efficacy (VE) of the AS01E-adjuvanted RSVPreF3 O...

Background A tool, the Infection Risk Scan has been developed to measure the quality of infection control and antimicrobial use. This tool measures various patient-, ward- and care-related variables in a standardized way. We describe the implementation of this tool in nine hospitals in the Dutch/Belgian border area and the obtained results. Method...

Noroviruses (NoV) are the leading cause of epidemic acute gastroenteritis in humans worldwide and a safe and effective vaccine is needed. Here, a phase I, double-blind, placebo-controlled clinical trial was performed in 60 healthy adults, 18 to 40 years old. Safety (primary objective) and immunogenicity (secondary and exploratory objectives) of a b...

Background Despite the availability of effective vaccines against COVID-19, booster vaccinations are needed to maintain vaccine-induced protection against variant strains and breakthrough infections. This study aimed to investigate the efficacy, safety, and immunogenicity of the Ad26.COV2.S vaccine (Janssen) as primary vaccination plus a booster do...

Influenza vaccines remain the most effective tools to prevent flu and its complications. Trivalent or quadrivalent inactivated influenza vaccines primarily elicit antibodies towards haemagglutinin and neuraminidase. These vaccines fail to induce high protective efficacy, in particular in older adults and immunocompromised individuals and require an...

SYNOPSIS Background Inpatient quality indicators (IQIs) were previously developed to assess responsible antibiotic use. The aim of this study was the practice testing of these QIs in the hospital setting. Method This study was performed within a Dutch-Belgian border network of hospitals implementing the Infection Risk Scan (IRIS) point prevalence...

Background The aim was to investigate safety and immunogenicity of vaccine formulations against respiratory syncytial virus (RSV) containing the stabilized prefusion conformation of RSV fusion protein (RSVPreF3). Methods This phase I/II, randomized, controlled, observer-blind study enrolled 48 young adults (YA; 18–40 years) and 1005 older adults (...

OVX836 is a recombinant protein-based vaccine targeting the highly conserved influenza nucleoprotein (NP), which aims to confer a broad-spectrum protection against influenza. In a Phase 1 study, OVX836, administered intramuscularly, has been found safe and immunogenic. The 90µg and 180µg dose levels were selected to be further evaluated in this ran...

Background Additional safe and efficacious vaccines are needed to control the COVID-19 pandemic. We aimed to analyse the efficacy and safety of the CVnCoV SARS-CoV-2 mRNA vaccine candidate. Methods HERALD is a randomised, observer-blinded, placebo-controlled, phase 2b/3 clinical trial conducted in 47 centres in ten countries in Europe and Latin Ame...

Background: The objective of this study was to determine if feedback of adenosine triphosphate (ATP) measurements decreases environmental contamination within hospitals in the Dutch/Belgian border area. Methods: Standardized ATP measurements were conducted in nine hospitals on pre-defined fomites. Four different fomite groups were defined: medic...

Background Additional safe and efficacious vaccines are needed to control the COVID-19 pandemic. We aimed to analyse the efficacy and safety of the CVnCoV SARS-CoV-2 mRNA vaccine candidate. Methods HERALD is a randomised, observer-blinded, placebo-controlled, phase 2b/3 clinical trial conducted in 47 centres in ten countries in Europe and Latin Am...

A quadrivalent high-dose inactivated influenza vaccine (IIV4-HD) is licensed for adults ≥65 y of age based on immunogenicity and efficacy studies. However, IIV4-HD has not been evaluated in adults aged 60–64 y. This study compared immunogenicity and safety of IIV4-HD with a standard-dose quadrivalent influenza vaccine (IIV4-SD) in adults aged ≥60 y...

Importance There is a need for improved immunogenicity of hepatitis B virus (HBV) vaccines among young adults with risk of infection. Objectives To demonstrate manufacturing equivalence of a 3-antigen (3A) HBV vaccine, evaluate noninferiority of seroprotection rate (SPR) of 3A-HBV vs single-antigen (1A) HBV after 2 and 3 vaccine doses, and compare...

p>Importance: There is a need for improved immunogenicity of hepatitis B virus (HBV) vaccines among young adults with risk of infection. Objectives: To demonstrate manufacturing equivalence of a 3-antigen (3A) HBV vaccine, evaluate noninferiority of seroprotection rate (SPR) of 3A-HBV vs single-antigen (1A) HBV after 2 and 3 vaccine doses, and comp...

Background: The currently licensed quadrivalent MenACWY-CRM conjugate vaccine presentation consists of two vials (lyophilised MenA and liquid MenCWY) to be reconstituted before injection. A new fully liquid formulation in a single vial has been developed to further improve the vaccine presentation. Since the MenA structure is subject to hydrolytic...

Background We used the RNActive® technology platform (CureVac N.V., Tübingen, Germany) to prepare CVnCoV, a COVID-19 vaccine containing sequence-optimized mRNA coding for a stabilized form of SARS-CoV‑2 spike (S) protein encapsulated in lipid nanoparticles (LNP). Methods This is an interim analysis of a dosage escalation phase 1 study in healthy 1...

Introduction Un vaccin grippal inactivé quadrivalent à haute dose (QIV-HD), c’est-à-dire contenant 60 μg d’hémagglutinine (HA) par souche a été développé pour améliorer la protection des personnes âgées contre la grippe et ses complications. QIV-HD a été enregistré en France en avril 2020 sur la base d’études d’immunogénicité, d’efficacité clinique...

Background The seroprotection rate (SPR) of hepatitis B vaccination in adults is suboptimal. The aim of this study was to compare the SPR of a tri-antigenic hepatitis B vaccine (TAV), with a mono-antigenic vaccine (MAV) in adults of all ages. Methods This was a multicentre, double-blind, phase 3, randomised controlled trial (PROTECT) comparing the...

Background In a hospital setting, there is a need for rapid detection of SARS-CoV-2 to guide isolation measures and targeted admission. Aim First, we evaluated the diagnostic performance of five SARS-CoV-2 rapid nucleocapsid protein antigen detection (RAD) assays (Biosynex, Biotical, Orient Gene, Panbio, SD Biosensor). Secondly, we described the p...

Introduction In a first-in-human study immune responses to rabies virus glycoprotein (RABV-G)-mRNA vaccine were dependent on the route of administration, necessitating specialized devices. Following successful preclinical studies with mRNA encapsulated in lipid nanoparticles (LNP), we tested an mRNA-LNP formulation (CV7202). Methods In this phase...

Background Early 2020, a COVID-19 epidemic became a public health emergency of international concern. To address this pandemic broad testing with an easy, comfortable and reliable testing method is of utmost concern. Nasopharyngeal (NP) swab sampling is the reference method though hampered by international supply shortages. A new oropharyngeal/nasa...

Abstract Background: Additional safe and effective vaccines are needed to control the COVID-19 pandemic. Methods: HERALD is an ongoing phase 2b/3 randomised, observer-blinded, placebo-controlled clinical trial in ten countries in Europe and Latin America. SARS-CoV-2 naïve adults were randomised 1:1 to receive two doses of CVnCoV mRNA vaccine candi...

Background RSV is a common cause of respiratory acute illness in older adults (OA). We evaluated safety and reactogenicity of RSVPreF3 candidate vaccine in young adults (YA) and OA. Methods In this phase I/II, placebo-controlled, multi-country trial (NCT03814590), YA aged 18–40 years were randomized 1:1:1:1 and received 2 doses of Low-, Medium- or...

Background RSV causes significant disease burden in older adults, since reinfections are common and may lead to severe disease presentations while only supportive treatment is available. We present immunogenicity of different formulations of an investigational vaccine (RSVPreF3) in young and older adults. Methods This is a phase I/II, placebo-cont...

Background Two novel type 2 oral poliovirus vaccine (OPV2) candidates, novel OPV2-c1 and novel OPV2-c2, designed to be more genetically stable than the licensed Sabin monovalent OPV2, have been developed to respond to ongoing polio outbreaks due to circulating vaccine-derived type 2 polioviruses. Methods We did two randomised studies at two centre...

This first-in-human study (NCT03032588), conducted in Belgium, evaluated a new inactivated poliovirus vaccines (IPV) candidate based on Sabin poliovirus strains grown on the high-yield PER.C6® cell line. Healthy adults (N = 32) were randomized (1:1) to receive a single dose of PER.C6-based Sabin-IPV (sIPV, 15:35:112.5 DU/dose) or conventional Salk-...

There is an urgent need for vaccines to counter the COVID-19 pandemic due to infections with severe acute respiratory syndrome coronavirus (SARS-CoV-2). Evidence from convalescent sera and preclinical studies has identified the viral Spike (S) protein as a key antigenic target for protective immune responses. We have applied an mRNA-based technolog...

BACKGROUND The ongoing coronavirus disease (COVID)-19 pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) might be controlled by an efficacious vaccine. Multiple vaccines are in development, but no efficacious vaccine is currently available. METHODS We designed a multi-center phase 1/2a randomized, double-blinded, placeb...

Background: Early 2020, the COVID-19 epidemic became a public health emergency of international concern. To address this pandemic broad testing with an easy, comfortable and reliable testing method is of utmost concern. Nasopharyngeal (NP) swab sampling is the reference method though hampered by international supply shortages. A new oropharyngeal/n...

Most H1 influenza A viruses (IAVs) of swine are derived from past human viruses. As human population immunity against these IAVs gradually decreases, the risk of reintroduction to humans increases. We examined 549 serum samples from persons 0-97 years of age collected in Belgium during 2017-2018 for hemagglutination inhibiting and virus neutralizin...

Background Carbapenemase-producing Enterobacterales (CPE) have rapidly emerged in Europe, being responsible for nosocomial outbreaks. Aim Following an outbreak in the burn unit of Ghent University Hospital, we investigated whether CPE can spread between toilets through drain water and therefrom be transmitted to patients. Methods In 2017, the bur...

Background: Early 2020, a COVID-19 epidemic became a public health emergency of international concern. To address this pandemic broad testing with an easy, comfortable and reliable testing method is of utmost concern. The nasopharyngeal (NP) swab sampling is the reference method though hampered by international supply shortages. A new oropharyngeal...

Background: The objective of this study was to determine the level of environmental contamination in hospitals in the Dutch/Belgian border area, using ATP measurements. Design: A cross-sectional observational survey. Methods: Standardized ATP measurements were conducted in 9 hospitals on 32 hospital wards. Thirty pre-defined surfaces per hospi...

Background & objective: The objective of this study was to determine the effect from feedback of ATP measurements on environmental contamination within hospitals in the Dutch/Belgian border area. Setting: Standardized ATP measurements were conducted in 9 hospitals on pre-defined fomites. Four different fomite groups were defined: medical devices, p...

Background: Vaccines eliciting protective and persistent immune responses against multiple human immunodeficiency virus type 1 (HIV-1) clades are needed. This study evaluated the persistence of immune responses induced by an investigational, AS01-adjuvanted HIV-1 vaccine as long as 14 years after vaccination. Methods: This phase I, open-label, d...

Purpose of review: Antimicrobial resistance (AMR) is increasing in ICUs around the world, but the prevalence is variable. We will review recent literature and try to answer the question whether this is a myth or a new reality, as well as discuss challenges and potential solutions. Recent findings: AMR is diverse, and currently Gram-negative mult...

Background The objective of this study was to determine the level of environmental contamination in hospitals in the Dutch/Belgian border area, using ATP measurements. Design A cross-sectional observational survey Methods Standardized ATP measurements were conducted in 9 hospitals on 32 hospital wards. Thirty pre-defined surfaces per hospital ward...

Background The objective of this study was to determine the level of environmental contamination in hospitals in the Dutch/Belgian border area, using ATP measurements. Design A cross-sectional observational survey Methods Standardized ATP measurements were conducted in 9 hospitals on 32 hospital wards. Thirty pre-defined surfaces per hospital ward...

Background The objective of this study was to determine the level of environmental contamination in hospitals in the Dutch/Belgian border area, using ATP measurements. Design A cross-sectional observational survey Methods Standardized ATP measurements were conducted in 9 hospitals on 32 hospital wards. Thirty pre-defined surfaces per hospital ward...

Background Many adults fail to achieve seroprotection after receiving 3 doses of monovalent HepB vaccines such as Engerix-B® and the response decreases with age and with common co-morbidities. Sci-B-Vac™ is a trivalent HepB vaccine produced in mammalian cells, adjuvanted with aluminum hydroxide, which in addition to small S antigen, contains preS1...

Background: We report a recurrent outbreak of postoperative infections with extended-spectrum β-lactamase (ESBL)-producing E. cloacae complex in cardiac surgery patients, describe the outbreak investigation and highlight the infection control measures. Methods: Cases were defined as cardiac surgery patients in Ghent University Hospital who were...

For patients with bloodstream infections, rapid initiation of the appropriate antimicrobial therapy is essential in reducing mortality and morbidity. New developments and automation in clinical microbiology labs speed up the identification and susceptibility results but are expensive. To gain insight in the added value of the new workflows, we simu...

OBJECTIVE To compare different techniques of endoscope sampling to assess residual bacterial contamination. DESIGN Diagnostic study. SETTING The endoscopy unit of an 1,100-bed university hospital performing ~13,000 endoscopic procedures annually. METHODS In total, 4 sampling techniques, combining flushing fluid with or without a commercial endos...

Avian influenza continues to circulate and remains a global health threat not least because of the associated high mortality. In this study antibody persistence, booster vaccine response and cross-clade immune response between two influenza A(H5N1) vaccines were compared. Participants aged over 18-years who had previously been immunized with a clad...

Trial Flow Chart. (DOCX)

Baseline Characteristics of Groups at time of first vaccination. (DOCX)

TREND Statement Checklist. (PDF)

Safety and Immunogenicity of an Intramuscular, Inactivated, Split-Virion, Pandemic Influenza A/H5N1 Vaccine in Adults and the Elderly Clinical Trial Protocol, Amendment 3. (PDF)

The use of mobile air purification systems in hospitals is widely accepted and even promoted by the CDC, but turns out to be quite expensive. In this study, the Hospital Infection Control Team (HICT) of the Ghent University Hospital evaluated a more cost-effective mobile HEPA filter unit.

This phase II, randomized, double-blind study evaluated the immunogenicity of RTS,S vaccines containing Adjuvant System AS01 or AS02 as compared with non-adjuvanted RTS,S in healthy, malaria-naïve adults (NCT00443131). Thirty-six subjects were randomized (1:1:1) to receive RTS,S/AS01, RTS,S/AS02, or RTS,S/saline at months 0, 1, and 2. Antibody resp...

Background: In January 2011, as part of an antimicrobial stewardship program the Antimicrobial Management Team (AMT) at the Ghent University Hospital initiated a multidisciplinary Infectious Diseases Team (MIT) consisting of infectious diseases physicians, clinical microbiologists, and clinical pharmacists. The aim of this study is to describe the...

Background An electronic decision support programme was developed within the intensive care unit (ICU) that provides an overview of all infection-related patient data, and allows ICU physicians to add clinical information during patient rounds, resulting in prospective compilation of a database. Aim To assess the validity of computer-assisted surv...

This phase II, randomized, double-blind study evaluated the immunogenicity of RTS,S vaccines containing Adjuvant System AS01 or AS02 as compared with non-adjuvanted RTS,S in healthy, malaria-naïve adults (NCT00443131). Thirty-six subjects were randomized (1:1:1) to receive RTS,S/AS01, RTS,S/AS02, or RTS,S/saline at months 0, 1, and 2. Antibody resp...

The last report on pertussis seroprevalence in Belgium concerned samples collected during 1993–1994. In the context of the Eupert-Labnet WP6 seroprevalence study (comparing sera from 16 European member states), 1500 anonymized leftover diagnostic samples were collected randomly during the second semester of 2012 by the clinical chemistry laboratori...

Objective To evaluate the consistency of three commercial scale lots of candidate herpes simplex virus (HSV) type 2 (HSV-2) vaccine in adolescent girls. Methods A total of 554 healthy girls aged 10-17 years, from Belgium, Canada, and United States, were enrolled and randomized to receive one of the three manufacturing lots of the candidate glycopro...

There is variability in the pharmacokinetics (PK) of antibiotics (AB) in critically ill patients. Therapeutic drug monitoring (TDM) could overcome this variability and increase PK target attainment. The objective of this study was to analyse the effect of a dose-adaption strategy based on daily TDM on target attainment. This was a prospective, part...