Study of the Immunological and Virological Response of Patients With COVID-19 and Presenting an Asymptomatic or Pauci-symptomatic Form (AMBUCOV)

NCT ID: NCT04703114

Last Updated: 2025-08-28

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

Get a concise snapshot of the trial, including recruitment status, study phase, enrollment targets, and key timeline milestones.

Recruitment Status

COMPLETED

Clinical Phase

NA

Total Enrollment

57 participants

Study Classification

INTERVENTIONAL

Study Start Date

2021-02-05

Study Completion Date

2021-09-15

Brief Summary

Review the sponsor-provided synopsis that highlights what the study is about and why it is being conducted.

The purpose of this study is to describe the immunological and virological response of patients infected with CoV-2-SARS and presenting an asymptomatic or mildly symptomatic form, in particular the innate and adaptive response as well as the virological clearance kinetics.

The research hypothesis is that patients with an ambulatory form of SARS-CoV-2 infection, whether asymptomatic or mildly symptomatic, are able to mount an innate and adaptive immunological response capable of rapidly clearing the virus, in contrast to severe forms in which an early deficit of type 1 IFN response has been demonstrated, possibly responsible for a defect in the control of viral replication in the blood.

Detailed Description

Dive into the extended narrative that explains the scientific background, objectives, and procedures in greater depth.

A new coronavirus (SARS-CoV-2) was identified in December 2019 in the Wuhan region of China and is currently causing a global pandemic.

The disease, named COVID-19, causes an influenza syndrome associated with respiratory signs, but there are also asymptomatic and pauci-symptomatic forms. Approximately 2 to 3% of patients, primarily patients with pre-existing chronic diseases and the elderly, develop a very severe form responsible for an acute respiratory distress syndrome (ARDS) that can lead to death.

It has been shown that patients with a severe and critical form had an impaired type 1 interferon response, with decreased plasma levels of IFN-alpha2 in the most severe patients compared to hospitalized patients with a moderate form, and undetectable levels of IFN-beta. This lack of type 1 IFN response was associated with greater viral persistence in the blood and an exaggerated inflammatory response mediated primarily by the NF-kB pathway.

Almost all studies published to date on immune system disruption during CoV-2-SARS infection included mainly hospitalized patients requiring oxygen therapy due to their severity, assessed at the time of clinical worsening.

Thus, there is no or little data on immunological response profiles, particularly on type 1 IFN response but also on other aspects of the immunological response (adaptive cellular and humoral immunity), and its relationship with viral clearance kinetics during ambulatory forms of SARS-CoV-2 infection, whereas these forms represent more than 95% of the clinical forms.

The asymptomatic and pauci-symptomatic forms managed on an outpatient basis represent the most common form of CoV-2-SARS infection, with a favourable outcome in almost all cases.

A better description and understanding of the immunological profile, including type 1 IFN response and viral clearance kinetics in saliva, blood and feces, during asymptomatic and mild clinical forms will allow the identification of the major players in the immune response against SARS-CoV-2, and thus better define the responses that are lacking in severe patients.

Conditions

See the medical conditions and disease areas that this research is targeting or investigating.

Covid19 SARS-CoV-2

Study Design

Understand how the trial is structured, including allocation methods, masking strategies, primary purpose, and other design elements.

Allocation Method

NON_RANDOMIZED

Intervention Model

PARALLEL

Primary Study Purpose

DIAGNOSTIC

Blinding Strategy

NONE

Study Groups

Review each arm or cohort in the study, along with the interventions and objectives associated with them.

Symptomatic

40 symptomatic patients to COVID-19 infection

Group Type EXPERIMENTAL

Blood count

Intervention Type DIAGNOSTIC_TEST

Blood count at each visit

Blood collection

Intervention Type DIAGNOSTIC_TEST

Blood collection to understanding of the immunological profile at each visit

Nasopharyngeal swab

Intervention Type DIAGNOSTIC_TEST

Research of SARS-CoV-2 infection in nasopharyngeal swab by RT-PCR at day 8 and day 15

Saliva samples

Intervention Type DIAGNOSTIC_TEST

Research of SARS-CoV-2 infection in saliva samples at each visit (excepted inclusion)

Faeces samples

Intervention Type DIAGNOSTIC_TEST

Research of SARS-CoV-2 infection in faeces samples at day 3, day 15 and day 90

Genetic blood collection

Intervention Type GENETIC

Collection to further research at each visit

Data collection

Intervention Type OTHER

Demographics, symptoms, biological constants

Asymptomatic

40 asymptomatic patients to COVID-19 infection

Group Type EXPERIMENTAL

Blood count

Intervention Type DIAGNOSTIC_TEST

Blood count at each visit

Blood collection

Intervention Type DIAGNOSTIC_TEST

Blood collection to understanding of the immunological profile at each visit

Nasopharyngeal swab

Intervention Type DIAGNOSTIC_TEST

Research of SARS-CoV-2 infection in nasopharyngeal swab by RT-PCR at day 8 and day 15

Saliva samples

Intervention Type DIAGNOSTIC_TEST

Research of SARS-CoV-2 infection in saliva samples at each visit (excepted inclusion)

Faeces samples

Intervention Type DIAGNOSTIC_TEST

Research of SARS-CoV-2 infection in faeces samples at day 3, day 15 and day 90

Genetic blood collection

Intervention Type GENETIC

Collection to further research at each visit

Data collection

Intervention Type OTHER

Demographics, symptoms, biological constants

Interventions

Learn about the drugs, procedures, or behavioral strategies being tested and how they are applied within this trial.

Blood count

Blood count at each visit

Intervention Type DIAGNOSTIC_TEST

Blood collection

Blood collection to understanding of the immunological profile at each visit

Intervention Type DIAGNOSTIC_TEST

Nasopharyngeal swab

Research of SARS-CoV-2 infection in nasopharyngeal swab by RT-PCR at day 8 and day 15

Intervention Type DIAGNOSTIC_TEST

Saliva samples

Research of SARS-CoV-2 infection in saliva samples at each visit (excepted inclusion)

Intervention Type DIAGNOSTIC_TEST

Faeces samples

Research of SARS-CoV-2 infection in faeces samples at day 3, day 15 and day 90

Intervention Type DIAGNOSTIC_TEST

Genetic blood collection

Collection to further research at each visit

Intervention Type GENETIC

Data collection

Demographics, symptoms, biological constants

Intervention Type OTHER

Eligibility Criteria

Check the participation requirements, including inclusion and exclusion rules, age limits, and whether healthy volunteers are accepted.

Inclusion Criteria

* Adult patients
* Nasopharyngeal PCR positive for SARS-CoV-2 within 48 hours prior to inclusion in the study protocol, carried out in one of the participating outpatient screening centers
* Symptomatic patients (nasopharyngeal screening positive due to suggestive symptoms) or asymptomatic (nasopharyngeal screening positive due to screening after contact with a positive subject)
* Patients who have been informed and signed the consent
* Pregnant and breastfeeding women who may be included in the study.

Exclusion Criteria

* Patients with criteria for hospitalization at the time of diagnosis (seriousness criteria, impossibility of staying at home)
* Non-consent or inability to obtain consent,
* Patient with dementia or not authorized, for psychiatric reasons or intellectual failure, to receive information on the protocol and to give informed consent,
* Patient under guardianship / curatorship
Minimum Eligible Age

18 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

No

Sponsors

Meet the organizations funding or collaborating on the study and learn about their roles.

Fonds IMMUNOV

UNKNOWN

Sponsor Role collaborator

Assistance Publique - Hôpitaux de Paris

OTHER

Sponsor Role lead

Responsible Party

Identify the individual or organization who holds primary responsibility for the study information submitted to regulators.

Responsibility Role SPONSOR

Principal Investigators

Learn about the lead researchers overseeing the trial and their institutional affiliations.

Solen KERNEIS, Doctor

Role: STUDY_DIRECTOR

Assistance Publique - Hôpitaux de Paris

Locations

Explore where the study is taking place and check the recruitment status at each participating site.

Hôpital Cochin

Paris, Île-de-France Region, France

Site Status

Countries

Review the countries where the study has at least one active or historical site.

France

References

Explore related publications, articles, or registry entries linked to this study.

Lingas G, Planas D, Pere H, Porrot F, Guivel-Benhassine F, Staropoli I, Duffy D, Chapuis N, Gobeaux C, Veyer D, Delaugerre C, Le Goff J, Getten P, Hadjadj J, Bellino A, Parfait B, Treluyer JM, Schwartz O, Guedj J, Kerneis S, Terrier B. Neutralizing Antibody Levels as a Correlate of Protection Against SARS-CoV-2 Infection: A Modeling Analysis. Clin Pharmacol Ther. 2024 Jan;115(1):86-94. doi: 10.1002/cpt.3069. Epub 2023 Oct 20.

Reference Type BACKGROUND
PMID: 37795693 (View on PubMed)

Zhu N, Zhang D, Wang W, Li X, Yang B, Song J, Zhao X, Huang B, Shi W, Lu R, Niu P, Zhan F, Ma X, Wang D, Xu W, Wu G, Gao GF, Tan W; China Novel Coronavirus Investigating and Research Team. A Novel Coronavirus from Patients with Pneumonia in China, 2019. N Engl J Med. 2020 Feb 20;382(8):727-733. doi: 10.1056/NEJMoa2001017. Epub 2020 Jan 24.

Reference Type BACKGROUND
PMID: 31978945 (View on PubMed)

Yang X, Yu Y, Xu J, Shu H, Xia J, Liu H, Wu Y, Zhang L, Yu Z, Fang M, Yu T, Wang Y, Pan S, Zou X, Yuan S, Shang Y. Clinical course and outcomes of critically ill patients with SARS-CoV-2 pneumonia in Wuhan, China: a single-centered, retrospective, observational study. Lancet Respir Med. 2020 May;8(5):475-481. doi: 10.1016/S2213-2600(20)30079-5. Epub 2020 Feb 24.

Reference Type BACKGROUND
PMID: 32105632 (View on PubMed)

Hadjadj J, Yatim N, Barnabei L, Corneau A, Boussier J, Smith N, Pere H, Charbit B, Bondet V, Chenevier-Gobeaux C, Breillat P, Carlier N, Gauzit R, Morbieu C, Pene F, Marin N, Roche N, Szwebel TA, Merkling SH, Treluyer JM, Veyer D, Mouthon L, Blanc C, Tharaux PL, Rozenberg F, Fischer A, Duffy D, Rieux-Laucat F, Kerneis S, Terrier B. Impaired type I interferon activity and inflammatory responses in severe COVID-19 patients. Science. 2020 Aug 7;369(6504):718-724. doi: 10.1126/science.abc6027. Epub 2020 Jul 13.

Reference Type BACKGROUND
PMID: 32661059 (View on PubMed)

Lucas C, Wong P, Klein J, Castro TBR, Silva J, Sundaram M, Ellingson MK, Mao T, Oh JE, Israelow B, Takahashi T, Tokuyama M, Lu P, Venkataraman A, Park A, Mohanty S, Wang H, Wyllie AL, Vogels CBF, Earnest R, Lapidus S, Ott IM, Moore AJ, Muenker MC, Fournier JB, Campbell M, Odio CD, Casanovas-Massana A; Yale IMPACT Team; Herbst R, Shaw AC, Medzhitov R, Schulz WL, Grubaugh ND, Dela Cruz C, Farhadian S, Ko AI, Omer SB, Iwasaki A. Longitudinal analyses reveal immunological misfiring in severe COVID-19. Nature. 2020 Aug;584(7821):463-469. doi: 10.1038/s41586-020-2588-y. Epub 2020 Jul 27.

Reference Type BACKGROUND
PMID: 32717743 (View on PubMed)

Other Identifiers

Review additional registry numbers or institutional identifiers associated with this trial.

2020-A03102-37

Identifier Type: OTHER

Identifier Source: secondary_id

AMBUCOV

Identifier Type: -

Identifier Source: org_study_id

More Related Trials

Additional clinical trials that may be relevant based on similarity analysis.

COVID-19 Serology and Immunosenescence
NCT04563650 ACTIVE_NOT_RECRUITING NA
Myeloid Cells in Patients With Covid-19 Pneumonia
NCT04590261 NOT_YET_RECRUITING NA