One of the current health challenges in the face of the COVID-19 pandemic that started inWuhan in 2019, and still responsible for successive waves, is to better understand anddiagnose the infection.The new variants - delta, then omicron, which appeared in November 2021 and then theirsub-variants BA.2, then BA.4 and 5, and more recently BQ.1 and the sub-variant XBB.1.5are increasingly transmissible and responsible for some degree of immune escape. Hencethe importance of a better understanding of infection- or vaccine-induced immunity inorder to optimize existing prophylactic or therapeutic strategies, or even to developnew, more effective ones.Mucosal immunity could play a particularly important role in interrupting the infectioncycle at the entry point of the virus.The key role of innate immunity has been demonstrated in particular, via interferons andthe composition of the microbiota.Humoral immunity is the best documented. However, it tends to be eroded within a fewmonths. On the other hand, cellular immunity is more stable over time and would largelyexplain 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 alsoallow us to optimize or develop new diagnostic methods, necessary as a complement tovaccination, to effectively slow down the spread of the pandemic and reduce the severityof its impact on the population.The improvement of diagnostic methods will in turn improve the understanding of theinfection by providing increasingly reliable information on the characteristics of aninfection, its quantification, its dynamics, and its resolution, especially since theseparameters will be compared, at any time during the study, with reference methods and theimmunological status of the subject.The main significant improvements expected in the field of SARS-CoV-2 diagnosis arenotably the improvement of performance (reduction of false negatives in RT-PCR onnasopharyngeal samples), acceptability, simplicity of implementation in the field, andthe capacity to test transmission.The objective of this study is to identify and characterize SARS-CoV-2 infection and hostresponse, particularly mucosal immunity.
This is a prospective, longitudinal, descriptive study that will include adult
participants infected and uninfected with Sars-CoV-2 at the time of recruitment.
Participants will be divided into 3 groups of 30 evaluable subjects:
- uninfected,
- asymptomatically infected,
- symptomatically infected.
The participants will be identified within the Ile-de-France medical analysis
laboratories partners of the project.
Study with sample collection:
- For participants infected with SARS-CoV-2: Inclusion visit V0, ≤ 3 days after PCR
test Follow-up visit V1, 7 d ± 1 d after V0 Follow-up visit V2, 31 d ± 2 d after V0
V3 follow-up visit, 91 d ± 5 d after V0
- For participants not infected with SARS-CoV-2 : Inclusion visit V0, ≤ 3 days after
PCR test V1' visit, no more than 96 d after V0.
Biological: Blood sample collection
Blood sample collection between inclusion and 3 months max 55 ml at each visit
Other: Saliva sample collection
Saliva sample collection between inclusion and 3 months
Other: Nasopharyngeal and nasal sample collection
Nasopharyngeal and nasal sample collection between inclusion and 3 months
Other: Exhaled Breath Condensate (EBC)
Exhaled Breath Condensate (EBC) between inclusion and 3 months
Inclusion Criteria:
- Common criteria for all subjects:
- 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
- Benefiting from a Social Security scheme except for the Aide Médicale d'Etat
- Criteria for the SARS-CoV-2 infected participant group:
- Subject tested positive for SARS-CoV-2 by RT-PCR in one of the participating
laboratories for less than 72 hours
- Asymptomatic or with symptoms not requiring hospitalization regardless of
previous vaccination or infection status for SARS-CoV-2.
- Criteria for the SARS-CoV-2 uninfected group:
- Having tested negative for SARS-CoV-2 by RT-PCR
- Subject with no more than 3 co-morbidities listed by the HAS.
Exclusion Criteria:
- Criteria common to all subjects :
- 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
- SARS-CoV-2 RT-PCR result older than 3 days
- Existence of at least 3 co-morbidities known to be factors of severity (and
therefore representing risks of hospitalisation during follow-up)
- Existence of a previous known SARS-CoV-2 positivity less than 1 month old
(whatever the method used: RT-PCR or antigenic test)
- SARS-CoV-2 infected participant group criteria:
- For symptomatic subjects: onset of symptoms more than 4 days ago
- SARS-CoV-2 uninfected participant group criteria:
- Known history of infection and/or COVID-19 vaccination, within the previous 3
months
Institut Pasteur - ICAReB-clin
Paris, France
Investigator: Hélène Laude, MD
helene.laude@pasteur.fr
Hélène Laude, MD
33145688394
helene.laude@pasteur.fr
Hélène Laude, MD, Principal Investigator
Institut Pasteur