Covid-19 taskforce Latest news

COVID-19: CON-VINCE study enters homestretch

Originally launched in April 2020 under the aegis of the Research Luxembourg COVID-19 Taskforce, the CON-VINCE study aims to evaluate the prevalence and dynamics of the spread of COVID-19 within the Luxembourgish population, with a specific focus on asymptomatic and mildly symptomatic individuals. The last round of testing of the CON-VINCE participants is due to start in April 2021, approximately one year after the first set of visits upon inclusion in the study. The final wave will provide a comprehensive insight into the evolution and transmission of the disease over an extended timeframe, particularly from an immunity perspective.     

Under the leadership of Prof Rejko Krüger, Director of Transversal Translational Medicine (TTM) at the Luxembourg Institute of Health (LIH), CON-VINCE aims to detect asymptomatic and mildly symptomatic (oligosymptomatic) carriers by testing a panel of over 1,800 individuals, representative of the Luxembourgish population, for the presence of the SARS-CoV-2 virus and monitoring them over 12 months through a series of follow-up visits.

The annual follow-up testing phase under the project will begin on April 19th and is set to run over 5 to 6 weeks. As with the previous rounds of testing, all participants will be subjected once to a nasopharyngeal swab. Blood and stool samples will also be collected once as part of these follow-up visits, with the support of the laboratories Ketterthill, Laboratoires Réunis, BioneXt Lab, as well as of LIH and Laboratoire National de Santé (LNS) as associated partners for biospecimen collection. Biological sampling will be complemented by collecting additional information on confinement measures and vaccination through short follow-up questionnaires.

“From an operational perspective, participants will be asked to fill out the questionnaire provided through our partner TNS-Ilres. Upon completion, they will receive a voucher for sample collection at one of our partner laboratories. Collected samples will then be sent to the Integrated Biobank of Luxembourg (IBBL) for further analysis and storage”, explains Prof Rejko Krüger, coordinator of CON-VINCE.

Specifically, the collected nasopharyngeal swabs will undergo PCR testing to detect the presence of the SARS-CoV-2 virus, while blood samples will be analysed for antibodies (serological testing) to assess whether the participants have mounted an immune response following exposure to the virus or after vaccination.

We are expecting to obtain crucial information from this annual follow-up, particularly as pertains to the persistence of the antibody response over a full year. Moreover, this last visit will also allow us to analyse cell-based immunity, thereby giving us a more complete picture of the global immune response against the novel SARS-CoV-2”, adds Prof Krüger.

“For this reason, we would like to express our heartfelt gratitude to our partners, and specifically to the diagnostic laboratories and TNS-Ilres, for their unfaltering support and seamless collaboration throughout the past year, as well as to all volunteers who agreed to participate in the study. I take this opportunity to stress again the importance of their renewed participation, particularly in the context of this final wave, without which we would not be able to generate meaningful data and research outcomes for patients and the population in general”, he concludes.


CON-VINCE was launched in April 2020 as one of the several initiatives put in place under the aegis of the Research Luxembourg COVID-19 Taskforce to help contain the current pandemic. By screening a statistically representative panel of volunteers for the presence of the SARS-CoV-2 virus, CON-VINCE will identify asymptomatic and mildly symptomatic individuals and follow them up for a year. Ultimately, the study aims to generate accurate data on the prevalence and transmission of the disease within the Luxembourgish population.

CON-VINCE is led by a consortium of Luxembourgish research institutions, including LIH, its Integrated Biobank of Luxembourg (IBBL), the Luxembourg Centre for Systems Biomedicine (LCSB) of the University of Luxembourg and the Laboratoire National de Santé (LNS), with the support of the market research company TNS-ILRES for the selection of participants and of the national diagnostic laboratories Ketterthill, Laboratoires Réunis and BioneXt Lab as associated partners for sample collection. The study is co-funded by the Luxembourg National Research Fund (FNR) with an amount of EUR 1.4 million and by the Fondation André Losch through a financial commitment of EUR 800,000.  

Learn more on the CON-VINCE study

Scientific Contact:
  • Prof Rejko Krüger
  • Luxembourg Institute of Health
  • Tel: +352 26970-800 (8am – 5pm)
Press Contacts:

Covid-19 taskforce Latest news

COVID-19: mass screening reveals significant transmission risk from asymptomatic carriers

Based on the results of the large-scale testing programme run in Luxembourg, researchers show that asymptomatic SARS-CoV-2 carriers represent an important vector for transmission.

Large-scale testing for SARS-CoV-2 has been a topic of intense political and societal debate, the rationale for screening asymptomatic individuals having been in particular questioned. Nevertheless, whether asymptomatic carriers play an important role in population-based transmission has remained an essential question.

Luxembourg had been one of the first countries to implement a large-scale testing programme in May 2020, offering all of its residents and cross-border workers the opportunity to regularly and voluntarily get tested for free. The first phase of testing ran from 27 May until 15 September 2020 covered 49% of the resident and 22% of the cross-border worker populations, enabling the detection of 26% of all positive cases of the first epidemic wave.  This provided decision makers with evidence-based data and allowed to break infection chains early whereby the total number of cases would have been 43% higher without the testing over this period as shown by computer simulations.

In addition, large-scale testing provides a unique test case for assessing the role of asymptomatic carriers. Based on the contact tracing data from phase 1 of the large-scale testing programme, Luxembourg researchers revealed that asymptomatic SARS-CoV-2 carriers are likely similarly infectious compared to symptomatic individuals.

“Indeed, our data show that they infect on average a similar number of people as symptomatic individuals. Asymptomatic carriers, including those that are presymptomatic at the time of the test, thereby represent an important factor in triggering and sustaining infection chains.”

Paul Wilmes, Luxembourg Centre for Systems Biomedicine, University of Luxembourg

The testing strategy was designed in a 3-layered approach by estimating exposure to the disease and physical proximity to categorise activity sectors into high and medium risk. Not surprisingly, the analysis shows that people who worked in the high-risk sectors had greater odds of being tested positive. Moreover, the data revealed that individuals with a disposable household income of less than 30k€/year also had the highest risks of being infected.

In addition to its direct effect on infection dynamics, the large-scale testing also enabled the collection of a wealth of pseudonymised data that can now be exploited to learn more about SRAS-CoV-2.”

Ulf Nehrbass, CEO of the Luxembourg Institute of Health

By clarifying the role of asymptomatic carriers in the transmission of SARS-CoV-2, this analysis provides essential insights for the development of future population-level containment and mitigation strategies.

About the large-scale testing

As part of its lockdown exit strategy, Luxembourg implemented an extensive and unique nation-wide testing campaign, inviting its residents and cross-border workers to voluntarily get tested for SARS-CoV-2. The aim of this large-scale testing (LST) initiative was to limit the spread of the SARS-CoV-2 virus by identifying positive cases early, including among asymptomatic individuals, thereby pre-emptively breaking infection chains. At the same time, LST contribute to the close monitoring of the spread of the virus among the Luxembourg population.

The first phase of the LST, coordinated by the Luxembourg Institute of Health (LIH) and supported by researchers at the University of Luxembourg, ran from 27 May until 15 September 2020 and relied on 16 ‘drive-through’ and 1 ‘walk-through’ test stations, with a maximum theoretical capacity of 20,000 tests per day. The population was divided into three main categories with different testing intervals. The first category was composed of people exposed to a high infectious risk by their professional activity (such as healthcare professionals) whereas the second category consisted of those having resumed their professional activity or were about to get back to work. The third category encompassed representative samples of the general population. The recurrent testing of the contingents and the rigorous contact tracing not only aimed at breaking nascent infection chains but also at providing decision makers with evidence-based data. Over the first phase of the LST, a total of 566,320 tests was performed based on a total of 1,436,000 invitations, which corresponds to 69,7% of all tests performed and an overall response rate of 39,4%.

Learn more on the large-scale testing

Read the article on The Lancet Regional Health – Europe website


Covid-19 taskforce

CON-VINCE Study – Behind the scenes (PART I)

CON-VINCE as a role model for translational research collaboration in Luxembourg (PART I)
IBBL a as key integrator

On 8th April, the CON-VINCE study was officially launched, with the aim to assess the spread dynamics of the COVID-19 disease among the Luxembourgish population.

Only 2 days later, all necessary material for starting up was already available (many thanks to LIH Buildings & Equipments team), coordination between the numerous partners around a single workflow was optimal, and all security conditions (many thanks to LIH Compliance Office team) were met to start the study. A real feat!

Within just 10 days, 1862 people were recruited, biosampled and tested!

Throwback to a logistical, technical and human challenge, which was met thanks to the incredible collaboration of all the IBBL, LIH, LCSB, CHL staff and partner laboratories from BioNext, Ketterthill and Laboratoires Réunis.

(from left to right) Top Pic: Claire, Ana Lopes, Laura George, Margaux Henry, Maeva Munsch, Florian Simon, bottom left: Maeva M. Manuel C. François Massart (LCSB), Olivia Domingues, bottom right: Florian Simon, Charlene Verschueren, Ana Lopes, Margaux Schmitt, Bruno Santos 

Such an ant work was carried out by the IBBL Biorepository team and various volunteers. IBBL acted as a leader in the biosampling task force together with other stakeholders. Recruitment, as well as the coordination of collection partners, was a key point.

A huge thanks to IBBL Biorepository and Biorefinery teams who gave their all without counting the hours, so that everything could work smoothly!

As a result, in only 10 days, 3,370 kits for the collection of blood and pharyngeal samples and 1,650 kits for the collection of stool samples were distributed to the country’s partner laboratories at an unprecedented cadence.

Top left Pic: Maeva Munsch, Florian Simon, Top right: Simon bottom left: Laure Pauly, Valérie Schröder, bottom right: Katy Beaumont, Maeva M. et Florian S.

Blood and naso-pharyngeal samples from study participants collected at the 3 partner laboratories  (Ketterthill, BioneXt and Laboratoires Réunis) and including home visits, were and transported (twice a day, sometimes more) to IBBL Biorepository by Biologistics (important role in the quick start of this study).

They were then dispatched as follows:

  • naso-pharyngeal swabs to the LNS for SARS-CoV2 virus detection by amplifying ribonucleic acid (RNA) before returning to IBBL to be stored
  • blood samples to Biorefinery team for “processing”
  • transfer of forms for data encoding (cf step 5 photo bottom left)
Top left: Olivia Domingues., Mareike Neumann, Monica Marchese, Top right: Camille Bellora, Kate Sokolowska bottom left: Olivia Domingues, Charlene Verschueren, Achilleas Pexeras, Margaux Schmitt, Lucie Remark, Francois Massart bottom right Borja GOMEZ RAMOS, Olivia Domingues ,Margaux Schmitt

The “Processing” (manual and automated) consists in preparing different biological fractions for storage (serum or plasma for example). Training in the management of serum and plasma, naso-pharyngeal swabs, extracted RNA and stool aliquoting was necessary for volunteers and was organized in record time. The treated samples could then be redistributed to the LNS and LIH for analysis.

Daily processing of samples from 39 to 349 patients per day which, at the end of the first wave, allowed the storage of more than 37,000 aliquots, a large part of which was already used for research purposes within CON-VINCE and beyond.

Top left: Linda Hansen; bottom left pic: Maxime Hansen, Laure Pauly, Valerie Schröder; right: Femke Wauters. All from the Parkinson Research Clinic of NCER-PD.

A proper data collection was key to carry out this study.

Proper data encoding of the paper forms received with the samples was key to carry out this study and was done by our clinical team partners at CHL and UL. To link the participants to their samples through the paper forms and their questionnaire answers, the data team of the LCSB Computing Platform worked day and night from the beginning of the study to set up the complex and secure data infrastructure. This allows the information to be properly stored and synchronized, and updated daily with the results of the tests for the virus.

All those activities are still ongoing with the same team spirit! Thumbs up to all teams working on this great project!

“This unprecedented study, due to its complexity and urgency, was like the outline of a music score, which each one of us fed with his musical orientations. Conductors agreed, musicians practiced, others discovered their instruments, adapted, trained and above all helped each other, all in record time. The ultimate goal is to play this collaborative score in unison. Objective achieved: The melody is there! “

Katy Beaumont, Head of BioRepository at IBBL and COVID Fighter.
Covid-19 taskforce

CON-VINCE study results – second testing phase

CON-VINCE, a national research project aiming to evaluate the prevalence and dynamics of the spread of COVID-19 within the Luxembourgish population, was launched at the beginning of April under the umbrella of the Research Luxembourg COVID-19 Task Force. The second round of testing of the participants in the study (first follow-up after baseline testing) showed a declining infection rate and lower prevalence of the disease, while bringing forward the risk associated with asymptomatic individuals in the context of a second COVID-19 wave.

Following the first baseline screening of all participants between mid-April and May 2nd, a second testing exercise took place from May 4th to May 16th as a first follow-up. As part of this phase, all participants were subjected to a second nasal and oropharyngeal swab, followed by a PCR-based analysis to detect the presence of the SARS-CoV-2 virus. During this period, 2 participants out of the entire panel tested positive for the virus, i.e. 0.1%, compared to 0.3% for the first testing round, reporting only mild symptoms. This translates into an estimated 402 infected but asymptomatic or oligosymptomatic (with only mild symptoms) individuals in the Luxembourg population, excluding cross-border workers. “Despite the declining prevalence of the infection, it is important to point out that all the SARS-CoV-2 positive participants in our panel displayed mild or no symptoms and are therefore ‘silent carriers’. This means that they could potentially start new infection chains without knowing it”, explains Prof Rejko Krüger, principal investigator of the CON-VINCE study.


A serological test was also carried out to detect the presence of antibodies in the blood, which may be an indication of past exposure to the virus. The results showed that 38 participants (2.6%) had antibodies against SARS-CoV-2, compared to 2.09% during the first round of screening. “We noticed an increase in the proportion of participants with antibodies against the virus, although I stress again that the presence of antibodies does not mean that people are immune to COVID-19”, adds Prof Krüger.


The participation in the study has also shown positive results, with over 94% of participants of the first testing phase having enrolled for the follow-up round. “We would like to extend our gratitude to all volunteers who renewed their participation in our study. Without their continued motivation and commitment, we would not be able to generate meaningful data and research outcomes for patients and the population in general”, says Prof Krüger. “To keep encouraging enrolment in the upcoming follow-up tests as participants progressively return to work, we will make it possible for them to obtain a certificate of participation in CON-VINCE upon request at the laboratories”, he concludes.


In addition to generating data on SARS-CoV-2 infection, CON-VINCE allows participants to make additional key contributions to a variety of related research questions in the context of the COVID-19 pandemic. Namely, the information collected during the study will help answer questions on mental wellbeing, immune response and immunity, infection pathways, the role of the gut microbiome, genetic predisposition and the socio-economic impact of COVID-19. Indeed, CON-VINCE differs from the newly-launched large scale testing (LST) initiative in that it does not aim to simply give a snapshot of the infection status at the time of testing. On the contrary, participants choosing to get tested in the framework of CON-VINCE provide their biological samples for research purposes, in order to support additional studies. For instance, although not compulsory, CON-VINCE participants are strongly encouraged to donate stool samples since SARS-CoV-2 can also be detected through the analysis of faeces. These samples can then be used to perform further analyses as part of other research projects (e.g. detection of the virus in wastewater and elucidation of the role of the gut microbiome composition in determining different susceptibilities to COVID-19).


The success of the project relies on the multidisciplinary expertise of its consortium partners, each implicated in different aspects of the multifaceted study. Specifically, the Luxembourg Institute of Health (LIH), the Centre Hospitalier de Luxembourg (CHL), the University of Luxembourg with its Luxembourg Centre of Systems Biomedicine (LCSB), the Luxembourg Institute of Socio-Economic Research (LISER), the Laboratoire National de Santé (LNS) and the Luxembourg Institute of Science and Technology (LIST) contributed to the establishment of the study protocol and setup of the case report form (CRF). TNS Ilres, Laboratoires Réunis, BioneXtLAB and Ketterthill are involved in recruitment and data collection. The LCSB and LIH are involved in data integration and storage. Laboratoires Réunis, BioneXtLAB and Ketterthill are responsible for sample collection, while the Integrated Biobank of Luxembourg (IBBL) ensures sample processing and storage. CON-VINCE is financially supported by the Luxembourg National Research Fund (FNR) and the André Losch Foundation.

Covid-19 taskforce

First results of the CON-VINCE study

CON-VINCE, a national research project aiming to evaluate the prevalence and dynamics of the spread of the COVID-19 disease within the Luxembourgish population, was launched at the beginning of April under the umbrella of the Research Luxembourg COVID-19 Task Force. Following the successful recruitment and first testing effort of more than 1800 participants over the age of 18, a first publication has now been uploaded on the preprint server medRxiv (Reference: MEDRXIV/2020/092916) and will be soon submitted for peer-reviewed scientific publication.
Low rate of infection but with potential for unnoticed virus spread

All participants already underwent a nasal and oropharyngeal swab followed by PCR-based virus test. The PCR analysis aims to detect the presence of the SARS-CoV-2 virus. Currently, 5 participants (0.3%) out of the whole panel tested positive for the virus, with individuals being asymptomatic or presenting only mild symptoms.

“Based on these very first numbers, we estimate that 1449 people in Luxembourg alone and without taking into account cross-border workers could be currently infected and show no or only mild signs of the disease”, explains Prof. Rejko Krüger, principal investigator of the CON-VINCE study. “Therefore, they could infect others without even knowing it.”

This highlights why there is a need for a large-scale testing strategy. Asymptomatic carriers need to be identified and isolated, ideally before people return to their workplace.

Almost 2% of the population has been in contact with the virus

In addition, participants underwent a serological test which aims to detect the presence of antibodies in the blood. These tests showed 35 participants (1,9%) have IgG antibodies against SARS-CoV-2, indicating that these people may have had contact with the virus during the last weeks.

“It is important to highlight that the presence of antibodies in the blood is not a proof that people are immune,” details Prof. Rejko Krüger. “It is yet unknown how long the antibodies stay in the blood and how effective they are against the virus. A positive serological test is therefore not a guarantee of protective immunity.”

Communication of positive test results to participants

In case of a positive result of either the PCR analysis or the serological test, a medical doctor of the CON-VINCE study will inform the participant as well as their treating physician. To ensure the anonymity of the participants and protection of personal data, the research study was designed so that only the medical doctors of the study team are able to track the participants’ identity and inform participant about test results in the specific and previously defined case that the result is positive.

Hence, if the participants are not contacted by a medical doctor belonging to the CON-VINCE team within two working days or 2 weeks after the visit to the laboratory, it means their PCR analysis or serology test, respectively, were negative. Following up all participants regularly for two months and then after a year will help understand better the prevalence and transmission of the disease as well as the infection rate in Luxembourg’s population.

Screening a statistically representative panel

Volunteers for the CON-VINCE study were recruited within the pool of 18.000 panel members of TNS Ilres which is as representative as possible of the whole population of the Grand Duchy. The study was carefully designed to both meet highest scientific standards and be feasible within the current constraints due to the emergency situation. In order to do that, CON-VINCE focuses on three criteria to select participants: age, gender, and residency.

“In every study design, researchers have to make choices and take them into consideration when interpreting results,” explains Prof. Ulf Nehrbass, spokesperson of the Research Luxembourg COVID-19 Task Force. “Taking further criteria into account would require a significantly larger number of participants. Therefore, other factors such as household composition, social status or lifestyle could not be considered given the time, organisational, and financial framework of the study.”

The exact methodology will be published in scientific journals, and potential limitations will be taken into accounts when analysing the data.

Successful start thanks to a collaborative effort

Setting up and executing such a comprehensive study in such a short time requires a huge team effort and important input from all the parties involved. This would not have been possible without the contribution of more than 1800 volunteers who agreed to participate in the study, the expertise of the Luxembourgish research institutions – the Luxembourg Institute of Health (LIH), the University of Luxembourg and the Laboratoire National de Santé (LNS) – and the input of several partners: Centre Hospitalier de Luxembourg, TNS-ILRES, Ketterthill, Laboratoires Réunis, and BioneXt Lab. The CON-VINCE study has been funded by the Luxembourg National Research Fund (FNR) and the André Losch Foundation.

“The Research Luxembourg COVID-19 task force wishes to express their greatest thanks to all these people who are key in making CON-VINCE a success for their invaluable commitment to the project,” concludes Rejko Krüger. “We are particularly thankful to the more than 1800 volunteers for their effort and continuing support of this longitudinal research study until 2021. Their repeated participation is crucial in understanding how the prevalence and spread of the virus evolves in Luxembourg over time.”

Read in French
Read in German

Covid-19 taskforce

Testing asymptomatic individuals to assess COVID-19 spread in Luxembourg

The Research Luxembourg COVID-19 task force announces the launch of “CON-VINCE ”, a study that aims to evaluate the dynamics of the spread of the COVID-19 disease within the Luxembourgish population.
The project is one of the several initiatives put in place under the aegis of the task force to help contain the current pandemic. It will test about 1,500 people for the presence of the SARS-CoV-2 virus and follow-up only the asymptomatic and mildly symptomatic individuals. This will generate accurate data on the transmission of the disease, ultimately assisting policy-makers in taking evidence-based decisions over the course of the coming weeks.

Asymptomatic individuals – often referred to as “silent carriers” – and mildly symptomatic carriers play a significant role in the spread of the virus. However, they currently remain largely unassessed, since diagnostic testing is performed predominantly on people with clear COVID-19 symptoms. In order to put in place effective measures to stave off the COVID-19 infection, it is crucial to systematically test a representative sample of the population in order to identify all individuals carrying the SARS-CoV-2 virus, regardless of their symptoms.

In this context, “CON-VINCE” has been launched today with the aim of testing a panel of approximately 1,500 participants over the age of 18 and detecting the three main groups of asymptomatic or mildly symptomatic people. Specifically, these include:
  • individuals who are “virus-free” and therefore asymptomatic;
  • people who are currently infected but present mild or no symptoms;
  • and those who were infected but are at present free of the virus.

Panel participants will be recruited by TNS Ilres and tested for SARS-CoV-2 through a specific molecular biology technique[1]. The analyses will initially be carried out on collected nasal and pharyngeal swabs, and subsequently extended to blood and other sample types. Participants testing positive for SARS-CoV-2 but displaying mild or no symptoms will be followed up over one year, together with virus-free individuals. Conversely, symptomatic patients will be excluded from the study and undergo regular treatment instead.

“To the best of our knowledge, asymptomatic carriers are not systematically monitored in any of the countries affected by the COVID-19 pandemic. Therefore, at present, no comprehensive data on the epidemiology and dynamics of the disease exist. CON-VINCE aims to fill this gap by providing reliable information on the nature, prevalence and transmission modality of COVID-19 in the Grand Duchy, therefore guiding national and international decision-makers in mounting an effective public health, political and economic response to the pandemic”, explains Prof Rejko Krüger, Director of Transversal Translational Medicine at the Luxembourg Institute of Health (LIH)[2] and coordinator of the “CON-VINCE” study.  

“In parallel, the project will also allow us to track the psychological and socio-economic impact of long-term containment measures on the general population and help us define clearer timeframes for lifting the current stringent confinement strategies”, concludes Prof Ulf Nehrbass, Chief Executive Officer at LIH and spokesperson of the Research Luxembourg COVID-19 task force.

“The CON-VINCE study represents the logical next step of the extensive testing of our population to better prevent the spread of the virus. We continue to put huge efforts to gather the best information in order to get ahead of the virus”, adds Minister of Health Paulette Lenert.

The “CON-VINCE” study is led by a consortium of Luxembourgish research institutions, including LIH and the Luxembourg Centre for Systems Biomedicine (LCSB) of the University of Luxembourg. The Luxembourg National Research Fund (FNR) is co-funding the study with an amount of 1.4 million Euro. The market research company TNS-ILRES, Ketterthill, Laboratoires Réunis and BioneXt Lab are associated partners in this study.

“Thanks to the task force that was launched two weeks ago, the public research institutions in Luxembourg have joined forces in the fight against COVID-19 and can provide valuable support and knowledge to help us make data-based decisions. The CON-VINCE study will be one of the key elements for an empirical basis in the handling of the current crisis.”

Claude Meisch, Minister of Higher Education and Research.

Communicated by Ministry of Health, Ministry of Higher Education and Research, Research Luxembourg

Press contact: Didier Goossens,

[1] To be noted that the diagnostic approach of the study is for research purposes only, and does not replace nor take resources from  regular care-based diagnostics. Participants testing positive for SARS-CoV-2 will undergo a confirmatory regular care-based diagnostic test in accredited laboratories. 

[2] Prof Krüger’s additional affiliations are as follows: FNR PEARL Chair and Head; Clinical and Experimental Neuroscience, Luxembourg Centre for Systems Biomedicine (LCSB), University of Luxembourg; Coordinator National Center for Excellence in Research – Parkinson’s disease (NCER-PD), Parkinson Research Clinic, Centre Hospitalier de Luxembourg.

Tests de dépistage sur des personnes asymptomatiques afin d’évaluer la propagation du COVID-19 au Luxembourg

Lancement de l’étude CON-VINCE

La task force COVID-19 de l’initiative Research Luxembourg annonce le lancement de CON-VINCE,  une étude scientifique visant à évaluer les dynamiques de la propagation du COVID-19 dans la population luxembourgeoise. Ce projet s’inscrit dans le cadre de plusieurs initiatives lancées sous l’égide de la task force afin de contribuer à endiguer la pandémie. Il vise à effectuer des tests de dépistage du virus SARS-CoV-2 sur environ 1.500 personnes et de faire un suivi des personnes ne présentant pas ou peu de symptômes. Il permettra de générer des données précises sur la transmission de la maladie et aidera ainsi le gouvernement à prendre des décisions basées sur des données scientifiques dans le courant des semaines à venir.  

Les personnes asymptomatiques – également appelées “porteurs sains” – et les porteurs présentant de faibles symptômes jouent un rôle important dans la propagation du virus. Cependant, la plupart de ces cas ne sont actuellement pas diagnostiqués, étant donné que les tests de dépistage sont surtout effectués sur des personnes présentant des symptômes clairs de la maladie. Afin de mettre en place des mesures efficaces pour endiguer la propagation du COVID-19, il est essentiel d’effectuer des tests systématiques sur un échantillon représentatif de la population afin d’identifier tous les porteurs du virus SARS-CoV-2, indépendamment de leurs symptômes.

Dans ce contexte, l’étude CON-VINCE a été lancée aujourd’hui dans le but d’effectuer des tests de dépistage sur un groupe d’environ 1.500 participants âgés de plus de 18 ans et d’identifier les trois principaux groupes de personnes présentant des symptômes faibles ou nuls. Spécifiquement, il s’agit des groupes suivants:

  • les individus non infectés et ne présentant par conséquent pas de symptômes ;
  • les personnes actuellement infectées, mais ne présentant pas ou peu de symptômes ;
  • ceux qui étaient infectés mais sont désormais guéris du virus.

Les participants seront recrutés par TNS Ilres et soumis à un test de dépistage du virus SARS-CoV-2 ayant recours à une technique spécifique de biologie moléculaire[1]. Les analyses seront initialement réalisées sur des prélèvements naso-pharyngés et ultérieurement étendues à des échantillons de sang ou autres types d’échantillons. Les participants dont le test est positif, mais qui présentent des symptômes faibles ou nuls seront suivis sur une période d’un an, de même que les personnes non-infectées. Les patients symptomatiques seront par contre exclus de l’étude et recevront le traitement habituel.

Prof. Rejko Krüger (Director of Transversal Translational Medicine au Luxembourg Institute of Health (LIH) et coordinateur de l’étude CON-VINCE : « A notre connaissance, les porteurs asymptomatiques ne sont pas systématiquement suivis dans aucun des pays affectés par la pandémie du COVID-19. Pour cette raison, il n’y a pas actuellement de données exhaustives sur l’épidémiologie et les dynamiques de la maladie. L’étude CON-VINCE vise à combler cette lacune en fournissant des informations fiables sur la nature, la prévalence et les modalités de transmission du COVID-19 au Grand-Duché, aidant ainsi les décideurs nationaux et internationaux à adopter une réponse efficace d’un point de vue politique, économique et de santé publique ».

Prof. Ulf Nehrbass (directeur général du LIH et porte-parole de la task force COVID-19 de Research Luxembourg) : « En parallèle, le projet nous permettra d’évaluer l’impact psychologique et socio-économique de mesures de confinement à long terme sur la population générale and nous aidera à définir un cadre temporel plus clair pour lever les actuelles stratégies de confinement strictes ».

Paulette Lenert, ministre de la Santé: « L’étude CON-VINCE représente la prochaine étape logique pour atteindre un vaste dépistage de la population, afin d’éviter la propagation du virus. Nous continuons à faire de grands efforts pour recueillir les informations les plus pertinentes pour pouvoir devancer le virus ».

L’étude CON-VINCE est menée par un consortium d’institutions de recherche luxembourgeoises, incluant le LIH et le Luxembourg Centre of Systems Biomedicine (LCSB) de l’Université du Luxembourg. L’institut d’étude de marché TNS-Ilres ainsi que les laboratoires Ketterthill, Laboratoires Réunis et BioneXt Lab sont des partenaires associés de l’étude.

Claude Meisch, ministre de l’Enseignement supérieur et de la Recherche : « Grâce à la task force lancée il y a deux semaines, les institutions de recherche publiques au Luxembourg ont rassemblé leurs forces dans la lutte contre le COVID-19 et peuvent nous fournir un soutien et des connaissances essentielles afin que nous puissions prendre des décisions basées sur des données scientifiques. L’étude CON-VINCE sera un des éléments-clé d’une base empirique pour la gestion de cette crise ».  

Communiqué par le Ministère de la Santé, le Ministère de l’Enseignement supérieur et de la Recherche et Research Luxembourg

Contact presse: Didier Goossens,

Info pour les journalistes

A propos de l’échantillon statistiquement représentatif

Le choix des participants de cet échantillon doit refléter exactement la composition de la population luxembourgeoise en termes d’âge, de sexe et de géographie afin d’éviter des résultats biaisés et statistiquement inexacts. Pour cette raison, le LIH contactera directement les candidats éligibles pour participer à l’étude. A ce stade, la participation de volontaires de la population générale n’est malheureusement pas (encore) possible.

A propos de Research Luxembourg

Research Luxembourg est une initiative commune des principaux acteurs de la recherche publique luxembourgeoise [Luxembourg Institute of Health (LIH); Luxembourg Institute of Socio-Economic Research (LISER); Luxembourg Institute of Science and Technology (LIST); Laboratoire national de santé (LNS) ; Université du Luxembourg; Fonds National de la Recherche (FNR)], sous la coordination du ministère de l’Enseignement supérieur et de la Recherche, dont le but principal est de promouvoir la coopération scientifique au Luxembourg et de communiquer les activités du secteur dans son ensemble.

[1] Il est à noter que l’approche diagnostique de l’étude sert à des fins de recherche uniquement et ne remplace pas et n’utilise pas de ressources du dépistage habituel à des fins de soins. Les participants testés positifs au virus SARS-CoV-2 seront soumis au test de dépistage habituel dans un laboratoire accrédité afin de confirmer le diagnostic.  

Abschätzung der Verbreitung von Covid-19 durch Testen asymptomatischer Personen

Die “CON-VINCE”-Studie beginnt

Die Research Luxembourg COVID-19 Arbeitsgruppe teilt mit, dass die „CON-VINCE[1]”-Studie beginnt, bei der die Dynamik der Verbreitung der Covid-19 Krankheit in der luxemburgischen Bevölkerung untersucht wird. Dieses Projekt ist eine von zahlreichen Initiativen unter der Schirmherrschaft der Arbeitsgruppe um dabei zu helfen die aktuelle Pandemie einzudämmen. Im Zuge der Studie werden etwa 1.500 Personen auf Vorhandensein des SARS-CoV-2 Virus getestet wobei lediglich die asymptomatischen und mild verlaufenden Fälle weiter verfolgt werden. Dies wird die Erhebung von Daten über den genauen Verbreitungsverlauf der Krankheit ermöglichen, was Entscheidungsträgern dabei helfen kann faktenbasierte Entscheidungen im Verlauf der nächsten Wochen zu treffen.

Asymptomatische Personen – oft auch als „stille Überträger“ bezeichnet – sowie Patienten mit nur milden Symptomen spielen eine entscheidende Rolle bei der Verbreitung des Virus. Bislang sind diese Gruppen jedoch nur wenig untersucht worden, da sich die diagnostischen Tests hauptsächlich auf Menschen mit klaren Covid-19 Symptomen konzentrieren. Um effektive Maßnahmen zur Abwehr der Covid-19 Infektion ergreifen zu können, ist es jedoch entscheidend systematisch eine repräsentative Stichprobe aus der Bevölkerung zu testen, um Träger des SARS-CoV-2 Virus unabhängig von ihren Symptomen zu identifizieren.

In diesem Kontext wurde heute die „CON-VINCE” ins Leben gerufen, die zum Ziel hat eine Gruppe[2]  aus etwa 1.500 volljährigen Teilnehmern zu testen und die drei Hauptgruppen der asymptomatischen oder mild symptomatischen Patienten zu identifizieren. Im Einzelnen beinhalten diese Gruppen:

  • Personen die frei von Virus und daher asymptomatisch sind
  • Menschen, die zwar mit dem Virus infiziert sind, jedoch nur milde oder keine Symptome zeigen
  • Patienten, die infiziert wurden, jetzt jedoch frei von dem Virus sind

Teilnehmer an der Studie werden durch das TNS Ilres rekrutiert und mithilfe einer speziellen molekularbiologischen Technik auf das SARS-CoV-2 Virus getestet[3].. Für die Analysen werden zunächst Abstriche aus Nase- und Rachenraum verwendet, später werden auch andere Tests durchgeführt wie beispielsweise Blutuntersuchungen. Teilnehmer, die positiv auf SARS-CoV-2 getestet wurden, jedoch nur milde oder keine Symptome aufweisen sowie auch Virus-freie Personen werden ein Jahr lang weiter beobachtet. Im Gegenzug dazu werden Patienten mit deutlichen Symptomen der Krankheit von dieser Studie ausgeschlossen und erhalten eine reguläre Behandlung.

„Nach unserem derzeitigen Wissensstand werden asymptomatische Überträger in keinem der der Covid-19 betroffenen Länder systematisch verfolgt. Daher stehen zu Zeit auch noch keine umfassenden Daten zur Epidemiologie und der Dynamik des Krankheitsverlaufes zur Verfügung. CON-VINCE zielt darauf ab, diese Lücke durch Bereitstellung verlässlicher Informationen über die Natur, Verbreitung und Art des Virus im Großherzogtum zu schließen, um hierdurch nationale und internationale Entscheidungsträger dabei zu unterstützen, ein effektives Gesundheitssystem sowie ökonomische und politische Maßnahmen zu implementieren“, erklärt Prof. Rejko Krüger, Direktor der Transversalen Transnationalen Medizin am Luxembourg Institute of Health LIH)[4] und Koordinator der „CON-VINCE“-Studie.

„Parallel hierzu wird dieses Projekt es uns auch ermöglichen, psychologische und sozialökonomische Folgen der Langzeit-Eindämmungsmaßnahmen auf die allgemeine Bevölkerung zu analysieren und dabei helfen klare Zeitrahmen zur Lockerung der aktuellen stringenten Isolationsmaßnahmen zu definieren“, ergänzt Prof. Ulf Nehrbass, Geschäftsführer des LIH und Sprecher der Research Luxembourg COVID-19 Arbeitsgruppe.

“Die CON-VINCE-Studie stellt den nächsten logischen Schritt der umfangreichen Tests an unserer Bevölkerung dar, um die Ausbreitung des Virus besser zu verhindern. Wir unternehmen weiterhin große Anstrengungen, um die besten Informationen zu sammeln, damit wir das Virus besser bekämpfen können”, fügt Gesundheitsministerin Paulette Lenert hinzu.

Die “CON-VINCE”-Studie wird von einem Konsortium luxemburgischer Forschungseinrichtungen geleitet, darunter das LIH und das Luxembourg Centre for Systems Biomedicine (LCSB) der Universität Luxemburg. Der Nationale Forschungsfonds Luxemburgs (FNR) kofinanziert die Studie mit einem Betrag von 1,4 Millionen Euro. Das Marktforschungsunternehmen TNS-ILRES, Ketterthill, Laboratoires Réunis und BioneXt Lab sind assoziierte Partner dieser Studie.

Pressekontakt: Didier Goossens,


Information für Journalisten

Die Auswahl der Studienteilnehmer muss dabei die Gesellschaftsstruktur der luxemburgischen Bevölkerung im Hinblick auf Alter, Geschlecht und Geographie abbilden, um eine Verzerrung der Ergebnisse und statistische Ungenauigkeiten zu vermeiden. Daher wird das LIH die in Frage kommenden Personen direkt kontaktieren, um an der Studie teilzunehmen. Zum gegenwärtigen Zeitpunkt ist die Teilnahme von Freiwilligen aus der Allgemeinbevölkerung leider (noch) nicht möglich.

Über Research Luxembourg

Research Luxembourg ist eine gemeinschaftliche Initiative der Hauptakteure der öffentlichen Forschung in Luxemburg: Luxembourg Institute of Health (LIH); Luxembourg Institute of Socio-Economic Research (LISER); Luxembourg Institute of Science and Technology (LIST); Laboratoire national de santé (LNS); University of Luxembourg; Fonds National de la Recherche (FNR), koordiniert durch das Ministerium für Hochschulwesen und Forschung. Das Hauptanliegen dieser Initiative ist es, die wissenschaftliche Kooperation in Luxemburg zu unterstützen und die Arbeit des gesamten Sektors nach außen zu kommunizieren.

[1] COvid-19 National survey for assessing VIral spread by Non-affected CarriErs

[2] Die Auswahl der Studienteilnehmer muss dabei die Gesellschaftsstruktur der luxemburgischen Bevölkerung im Hinblick auf Alter, Geschlecht und Geographie abbilden, um eine Verzerrung der Ergebnisse und statistische Ungenauigkeiten zu vermeiden.

[3] Es sei darauf hingewiesen, dass der diagnostische Aspekt dieser Studie lediglich für Forschungszwecke dient und keine reguläre medizinische Untersuchung ersetzt. Teilnehmer, die positive auf das SARS-CoV-2 Virus getestet wurden, werden einer zusätzlichen medizinischen Untersuchung in akkreditierten Laboren unterzogen. 

[4] Die weitern Affiliationen von Prof. Krüger sind: FNR PEARL Leitung und Vorsitz; Klinische und experimentelle Neurowissenschaften, Luxembourg Centre for Systems Biomedicine (LCSB), Universität Luxemburg; Koordinator am National Center for Excellence in Research – Parkinson’s disease (NCER-PD), Parkinson-Forschungsklinik, Centre Hospitalier de Luxembourg.