Can COVID-19 vaccines build strong immunity in people with weakened immune systems?

NCT ID NCT04824651

What the study statuses mean

This study's is highlighted.

Recruitment status, easiest to join first

Recruiting now
This trial is taking on new participants right now.
Not yet recruiting
Registered, but not yet taking participants.
By invitation only
Not open to general applications. Only people the study team invites can take part.
Paused
Paused for now. It may or may not start again.
Ongoing
Running, but no longer taking on new participants.
Completed This study
The trial has finished. Results may not be published yet.
Stopped early
Stopped early, before it reached the end. That can be for many reasons, including safety.
Cancelled
Cancelled before anyone took part.

Expanded access (not trials)

Expanded access
Not a trial. This treatment can be requested outside a study, case by case, for people who qualify.
Expanded access (paused)
Not a trial. The treatment can normally be requested outside a study, but is unavailable right now.
Expanded access (ended)
Not a trial. The treatment could once be requested outside a study, but no longer can.
Approved
The treatment has been approved, so it is available normally rather than through this programme.

When the status isn't known

Details not published
The full record has not been published yet, so there is little to show here.
Status unknown
This status has not been confirmed recently, so it may be out of date.

First seen Oct 16, 2026 · Last updated Oct 16, 2026

Summary

Researchers are following people with immune deficiency who receive COVID-19 vaccination through France's national campaign. The study measures antibodies and cellular immune responses in adults and in children aged 5 to 17. Blood samples collected over time help researchers understand how well the vaccine triggers protection in these groups.

What this could mean

Our plain-language read of the trial. This is informational only, not medical advice or a prediction.

Active substance
COVID-19 vaccine given through France's national vaccination campaign
What this could lead to
If the study shows how well people with immune deficiency respond to COVID-19 vaccination, doctors could use that information to tailor vaccine schedules or booster timing for these groups.
What could go wrong
This is an observational cohort, so it cannot prove that any particular vaccine strategy works. Immune responses vary widely between individuals, and results from this group may not apply to other populations or future vaccine formulations.

This is an AI summary of the original study and may miss details. Read our disclaimer.

Study facts

What this study's own registry entry says, in plain language.

Participants

6,922 people

The number who actually took part.

Started

Mar 2021

Finished

Dec 2024

Lead sponsor

A government agency

The lead sponsor is a government body.

Who can take part

This study's own entry requirements. Only the study team can say for certain whether you qualify.

Who is studied

6112 participants are inclued in the adult cohort. Enrollment objective in the ancillary study (pediatric cohort) from 5 to 17 years old (active enrollment): 810. The specific populations of the study for adult cohort: Patients with solid cancer solid organ transplant patients Allogeneic hematopoietic stem cell transplant patients Patients with chronic kidney failure disease and dialysis Patients with Multiple Sclerosis / Neuromyelitis optica spectrum disorder Patients with Chronic inflammatory rheumatism Patients with Autoimmune and autoinflammatory systemic diseases Patients with Hypogammaglobulinemia Patients obese non diabetic Patients diabetic (type I and II) obese or not People with HIV-1 (only) Control group (free from chronic conditions of interest listed above): 18 to 74 years ≥75 years (senior group) Vaccination schedule with Astra-Zeneca vaccine first dose and Pfizer vaccine second dose

Ages

18 years and older

Sex

Anyone

Healthy volunteers

Accepted

You do not need to have the condition being studied to take part.

Show the full entry requirements

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

These eligibility criteria only concern the adult cohort. INCLUSION CRITERIA : General inclusion criteria for all patients of all groups * Be 18 years or older * Get vaccinated against Covid-19 as part of the national vaccination campaign or having already received a first or second vaccine injection as part of the national vaccination campaign * Accept the conditions of participation corresponding to each sub-population * Commit to respecting the schedule of visits provided in the research protocol * Plan to reside in France for at least 2.5 years from inclusion date * Give their free, informed and written consent (at the latest on the day of inclusion and before any examination / samples) by signing the consent form * Be a member of or beneficiary of a social security scheme (State Medical Aid is not a social security scheme). General inclusion criteria for patients with a chronic condition of interest * Present at least one pathology listed * If the participant is participating in the in-depth immunology and virology study, they must have only one of the pathology of interest listed Inclusion criteria for control subjects • Be free from the chronic conditions of interest listed or other chronic conditions/treatment that may affect the immune response Inclusion criteria for control subjects free from chronic conditions of interest and with first injection with Astra-Zeneca vaccine AZD1222 and second injection with Pfizer ARNm vaccine BNT162b2 • Be vaccinated with a first injection with Astra-Zeneca vaccine AZD1222 and a second injection with Pfizer ARNm vaccine BNT162b2 NON INCLUSION CRITERIA : General non inclusion Criteria for all participants of all groups * Be under protective supervision (guardian or curatorship) * Being a pregnant or breastfeeding woman * Present a contraindication to Covid-19 vaccination : Have a known or suspected allergy to any component of the vaccine, Have had at-risk contact with a confirmed Covid-19 person in the last 7 days, Have presented clinical signs suggestive of Covid-19 in the last 7 days, Have an acute febrile episode on inclusion / vaccination, Have received a vaccine in the last 15 days ... * Have had a documented Covid-19 Infection (PCR or antigenic test) * Refuse that their Social Security number is collected for accessing the National Health Data System (NSDS)/Data Health Hub national health databases * For safety reasons, must agree to not enter in a vaccine clinical trial during the entire period of inclusion and follow-up of the research Specific non inclusion criteria for PLWHIV * Being infected with HIV-2 * Presenting another cause for immunosuppression (undergoing immunosuppressive treatment, biotherapy) * Presenting a non controlled opportunistic infection Specific non-inclusion criteria for control subjects * Have one or more of the chronic conditions of interest listed or affected by any other pathology or treatment that may affect the immune response (autoimmune/inflammatory pathology or immune deficiency not listed, liver failure, immunosuppressive therapy (like oral corticosteroids at \>= 10 mg/d Prednisone equivalent for more than 15 days) or radiotherapy within 6 months prior to inclusion or planned for the duration of the study) * Life expectancy of less than 2 years

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Conditions

The condition(s) this trial relates to.

As listed by the trial registrant

The condition terms exactly as the trial's registrant entered them.

Contacts and locations

Locations

  • Cmg-Ec U1219

    Bordeaux, France

  • Nîmes CHU

    Nîmes, France

  • Paris Cochin APHP

    Paris, France

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