One of the current health challenges in the face of the COVID-19 pandemic that started in Wuhan in 2019, and still responsible for successive waves, is to better understand and diagnose the infection.
The new variants - delta, then omicron, which appeared in November 2021 and then their sub-variants BA.2, then BA.4 and 5, and more recently BQ.1 and the sub-variant XBB.1.5 are increasingly transmissible and responsible for some degree of immune escape. Hence the importance of a better understanding of infection- or vaccine-induced immunity in order to optimize existing prophylactic or therapeutic strategies, or even to develop new, more effective ones.
Mucosal immunity could play a particularly important role in interrupting the infection cycle at the entry point of the virus.
The key role of innate immunity has been demonstrated in particular, via interferons and the composition of the microbiota.
Humoral immunity is the best documented. However, it tends to be eroded within a few months. On the other hand, cellular immunity is more stable over time and would largely explain the decrease in severe forms of the disease in vaccinated individuals.
The collection of biological resources that will be built up during this study will also allow us to optimize or develop new diagnostic methods, necessary as a complement to vaccination, to effectively slow down the spread of the pandemic and reduce the severity of its impact on the population.
The improvement of diagnostic methods will in turn improve the understanding of the infection by providing increasingly reliable information on the characteristics of an infection, its quantification, its dynamics, and its resolution, especially since these parameters will be compared, at any time during the study, with reference methods and the immunological status of the subject.
The main significant improvements expected in the field of SARS-CoV-2 diagnosis are notably the improvement of performance (reduction of false negatives in RT-PCR on nasopharyngeal samples), acceptability, simplicity of implementation in the field, and the capacity to test transmission.
The objective of this study is to identify and characterize SARS-CoV-2 infection and host response, particularly mucosal immunity.
Aged between 18 and 65 years included
Whose weight is greater than or equal to 50 kg and whose state of health is compatible with the collection of 55 ml of blood at one time and 111 ml in 28 days
Residing in the Ile-de-France region and able to travel to the 15th arrondissement of Paris for visits to ICAReB-Clin
Having given their consent to participate in the study
Subject under a protective measure (e.g., guardianship)
Participant in another biomedical research
For women: pregnant or breastfeeding women (declarative)
Subject with another acute infectious disease
Single group
Blood sample collection
Biological/VaccineBlood sample collection between inclusion and 3 months max 55 ml at each visit
Saliva sample collection
Other interventionSaliva sample collection between inclusion and 3 months
Nasopharyngeal and nasal sample collection
Other interventionNasopharyngeal and nasal sample collection between inclusion and 3 months
Exhaled Breath Condensate (EBC)
Other interventionExhaled Breath Condensate (EBC) between inclusion and 3 months
To characterize SARS-CoV-2 infection and host response, particularly mucosal immunity.
Measurement of mucosal anti-SARS-CoV-2 antibody levels and cytokines, composition of the local microbiota of the upper respiratory tract.
To characterize biomarkers of infection (stage, severity, prognosis) with new innovative direct or indirect diagnostic methods for SARS-CoV-2 and identify potential theranostic biomarkers.
Measurement of the capacity of the biomarkers to characterize the different stages, severity and prognosis of the infection, or theranostic potential.
To characterize the dynamics of infection and immunological response from the date of suspected infection and up to 3 months post-infection, or later, during the first year
Kinetics of virological evolution and immune response in different compartments (blood, upper and lower respiratory)
To develop tools to assess the contamination capacity of subjects.
Measurement of viral load in exhaled air condensates
To characterization of mucosal and humoral immunity.
Measurement and comparison of mucosal and humoral immunity parameters
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Institut Pasteur
Lead sponsor
Biogroup Laboratoire de biologie médicale
Collaborator
