CON-VINCE (COvid-19 National survey for assessing VIral spread by Non-affected CarriErs) is a national, monocentric, and longitudinal study aiming to evaluate the spread dynamics of the COVID-19 disease within the Luxembourgish population. Participants who are clinically asymptomatic or present with only mild symptoms will be followed up longitudinally, regularly tested for SARS-CoV-2 by RT-PCR, antibody status, and subjected to an epidemiological, clinical and biological phenotyping to better understand the nature, dynamics of infectivity and spread of the virus in the population. CON-VINCE will also track the psychological and socio-economic impact of long-term containment measures on the general population.

To capture the dynamics and impact of the virus spread in the Luxembourgish population, data and sample collection is done every two weeks for two months (4 times in total) with a final follow-up one year after the participant's inclusion in the study. Participants complete questionnaires before each sample collection. The baseline questionnaire captures demographic data, medical history, behavioral and psychological data, and socio-economic status. Participants provided information on medical history, history of allergies, smoking, and chronic medication taken regularly. COVID-19-related data and environmental conditions of the household were obtained.

Inclusion Criteria:

• Subjects aged 18 and older of both genders, with a full capacity of consent.
• SARS-CoV-2-positive individuals with an asymptomatic or oligosymptomatic infection (mild or oligosymptomatic disease course is defined as absence of fever and respiratory distress or cough not attributable to other known chronic disease).
• OR SARS-CoV-2-negative individuals at the time of inclusion.
• OR post-infectious SARS-CoV-2-negative individuals with acquired immunity to SARS-CoV-2 and a mild disease course.

Exclusion Criteria:

• Evolution of the COVID-19 disease requiring a hospital admission before inclusion in the study
• Presence of fever and respiratory distress/cough at the time of inclusion not attributable to other known chronic disease

Representative panel of the Luxembourgish population