Study of anti-SARS-CoV-2 (COVID-19) seroprevalence at the University of Liège (SARSSURV)

The University of Liège is going to conduct a very large-scale epidemiological study within its community. The aim is to define and, above all, to establish the conditions for decontamination and a return to a normal life.


For several months now, a multidisciplinary group of ULiège researchers has been developing a dashboard to determine the conditions for decontamination for a given group.

This dashboard must be fed with a large number of data: positivity rate, proportion of people with antibodies, vaccination status, presence of variants, etc. To collect this data, ULiège is going to carry out an epidemiological study with 2,500 volunteers: 1,000 members of staff and 1,500 students, i.e. almost 10% of the university community!

"This is one of the most ambitious epidemiological studies in the world and, in a new spirit of solidarity, we are calling on the university community to help us to define in a scientific manner the means of returning to a normal life," explains Professor Fabrice Bureau, Vice-Rector for Research and responsible, with Professor Pr Laurent Gillet, Professor Daniel Desmecht and Dr Gilles Darcis (University Hospital, CHU of Liège), for this seroprevalence study.

Who is concerned by this study?

The study, which began in April 2021, is continuing this new academic year. Only certain categories are not targeted:

  • Staff members whose contracts end before 31 December 2021,
  • Bachelor Bloc 1 students and graduating cohorts.

Currently, more than 1000 participants have agreed to continue their involvement in the study. However, in order to reach our goal, a new recruitment period will be launched in the new academic year.
Students who meet the inclusion criteria will receive an email invitation to participate in the study with a registration link. By clicking on this link, they will be redirected to an online platform where informed consent will be offered and where all data protection and privacy information (RGPD) will be detailed. Participation is voluntary.

Want to know more and/or participate in the study? Send an email to

2 phases of the study

Volunteers will be asked to sign a consent form to confirm their participation. Once their consent is received, they will receive a pack consisting of 13 saliva self-testing kits, 4 blood self-testing kits, 1 gargle kit and identification labels.

The first phase of the study aims to collect weekly saliva test results from each participant and, once a month, a blood self-test result. If either of these tests is positive, the participant is then invited to participate in phase 2. In addition, if a participant is vaccinated in the first phase, he or she is also invited to participate in phase 2.

What does Phase 1 consist of?

Saliva samples

For three months, the participant takes a weekly saliva self-test and drops it off at one of the ULiège collecting points.

Blood self-test

This test is carried out once a month using a Zentech kit. This is a self-test that can be carried out very easily at home by taking a drop of blood from the tip of the finger, in much the same way as a blood sugar test for a diabetic patient.

Demographic and clinical online survey

When registering, the participant is asked to complete an online demographic and clinical survey, in order to learn more about his or her clinical history (including SARS-CoV-2 infection) and possible treatments.

Vaccine hesitancy online survey

The participant will be asked to complete an online vaccine hesitancy survey at the time of enrolment and also after 3 months and finally at the end of the vaccination programme. The objective is to identify and understand, in a longitudinal process, the evolution of factors influencing the intention and decision to vaccinate against Covid-19.

What is phase 2?

If the saliva test and/or the blood self-test is positive, the participant enters phase 2 of the study. The same applies if the person is vaccinated during the study.

Saliva sample

As in phase 1, the participant continues to perform the saliva self-test once a week.


In case of a positive saliva test, the participant is asked to perform a gargle in order to identify and preserve the virus he/she carries. The sample is taken by the participant and collected at home to comply with the quarantine period.

Blood samples

For participants with a positive saliva test, a blood sample is taken at home after the 15-day quarantine period (and three months after entry into phase 2).

For participants who have been vaccinated or who test positive on the blood self-test, blood will be taken at home upon entry into phase 2 (and three months thereafter).

The purpose of these blood samples is to determine whether the antibodies developed are neutralising (i.e. capable of neutralising the virus) and to determine the extent and duration of their presence.

COVID-19 symptoms

For participants with a positive salivary test result, COVID-19 symptoms will be recorded twice a week for three weeks. Intensity scales will be used to clarify the perception of the symptoms. The questionnaire will be completed during a telephone conversation between the participant and the research nurse.

Vaccination-related symptoms

A questionnaire asking about different symptoms related to the different doses of vaccination will be offered to the participants at the time of the blood test.

Access the SARSSURV study platform

This study is also being conducted in parallel with other cohorts: front-line hospital staff, immunocompromised patients and patients with Alzheimer's disease and their families. These populations have particularities that make deconfinement difficult. "By studying them, we hope to be able to define the conditions under which a return to normal life is possible in these populations," says Professor Fabrice Bureau.


Recruitment and follow-up of participant


Share this page