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HealthyPhase 2CoviComparePNCT04824638

BNT162b2 Vaccination With 2 Doses in COVID-19 Negative Volunteers and With a Single Dose in COVID-19 Positive Volunteers

A Phase 2 study testing 3 doses of BNT162b2 vaccine and 2 dose of BNT162b2 vaccine in people with Healthy and Immunization; Infection, run by ANRS, Emerging Infectious Diseases at 11 sites in France.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

As previously shown, individuals who experienced COVID-19 have developed some protective immunity to reinfection. The magnitude and duration of protection from reinfection conferred by the infection may be weaker after an asymptomatic infection as it is after a symptomatic COVID-19 episode. Read more about this study

Who is it for?
Ages 18 years and olderHealthy volunteers can take part
Conditions the study is for
Healthy, Immunization; Infection
What is being tested?
3 doses of BNT162b2 vaccine and 2 dose of BNT162b2 vaccine
Could I receive a placebo?
No, everyone receives an active treatment
How many people
267 participants
Where
11 sitesFrance
Study dates
8 Mar 2021to 2 Dec 2023
Phase
Phase 2
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 years and older
  • All sexes
  • Healthy volunteers accepted
  • Adult, Older adult

Who may be able to join

  • 18 to 45 years old or at least 65 years old,
  • Healthy adults or stable medical condition for adults with pre-existing medical conditions. A stable medical condition is defined as disease not requiring significant change in therapy or hospitalization for worsening disease during 3 months before enrolment, nor expected to require any significant change in therapy or hospitalization for worsening disease in foreseeable future.
  • Group 1: Healthy adults with no previous history of SARS COV2 infection (PCR-, antigenic test- or chest TDM- or serology SARS-CoV-2-) Group 2: Healthy adults with history of infection with SARS COV 2 (PCR+, antigenic test+ or chest TDM+ or serology SARS-CoV-2 of more than 5 months) OR have been a household contact subject and have presented COVID-19 symptoms [Experienced at least TWO of the following systemic symptoms: Fever (≥ 38ºC), chills, myalgia, headache, sorethroat, new olfactory and taste disorder(s), gastrointestinal symptoms (diarrhea and/or vomiting) or at least ONE of the following respiratory signs/symptoms: cough, shortness of breath or difficulty breathing, OR clinical or radiographical evidence of pneumonia] since at least 5 months ago and have had a positive SARS-CoV-2 serology between this episode and pre-inclusion.
  • A female participant is eligible to participate if she is not pregnant or breastfeeding and one of the following conditions applies:
  • Is of non-childbearing potential. To be considered of non-childbearing potential, a female must be post-menopausal for at least 1 year or surgically sterile. OR
  • Is of childbearing potential and agrees to use an effective contraceptive method from at least 4 weeks prior to vaccination until at least 4 weeks after the last vaccination. A participant of childbearing potential must have a negative blood pregnancy test at enrolment visit.
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  • Understands and agrees to comply with the study procedures (visits, phone calls) based on Investigator judgement
  • Written and informed consent signed by the person and the investigator (no later than the day of pre-inclusion and prior to any examination realized in the frame of the trial) (article L1122-1-1 of the Public Health Code)
  • Affiliated or beneficiary of a social security scheme (article L1121-11 of the Public Health Code) (AME is not a social security scheme)
  • who agrees to be registered in the national file of persons who lend themselves to biomedical research (article L1121-16 of the Public Health Code).

Who cannot join

  • Participant is ill or febrile (body temperature ≥ 38.0°C) within 72 prior hours or and/or symptoms suggestive of COVID-19 or being contact subject within the past 14 days at enrolment visit.
  • (Ill or febrile participants may be re-scheduled within the trial inclusion period when no longer presenting symptoms, except if condition is COVID19)
  • Participants with positive PCR, antigenic test or chest TDM or serology to SARS-CoV-2 at the enrolment visit, only for the group1.
  • Participants who already received another anti-SARS-CoV-2-vaccine
  • Participants who received BCG given within the last year.
  • Use of immunosuppressive drugs like e.g. corticosteroids at a dosage > 10mg equivalent prednisone /day (excluding topical preparations and inhalers) within 3 months prior to enrolment or 6 months for chemotherapies
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  • Received immunoglobulin or other blood product within 3 months prior to enrolment or planned receipt of immunoglobulin or a blood product through study completion.
  • Received any vaccination within 4 weeks prior to first injection or plan to receive a licensed vaccine within 4 weeks after the last injection.
  • History of severe adverse reactions to vaccine administration, including anaphylaxis and related symptoms, such as rash, respiratory difficulty, laryngeal oedema and abdominal pain to vaccines, or history of allergic reaction likely to be exacerbated by any component of the anti-SARS-CoV-2-vaccine.
  • History of severe allergic event
  • Known HIV, active HCV or HBV infection
  • Any pathological condition, such as cancer, which may be susceptible of reducing immunity response
  • Any bleeding disorder considered as contraindication to intramuscular injection or phlebotomy
  • The use of investigational Ig, investigational monoclonal antibodies or convalescent serum are not allowed during the study
  • Any condition which in the opinion of the investigator may interfere with the aim of the study
  • Pregnant or breastfeeding or positive pregnancy blood test at enrolment visit.
  • An immediate family member or household member of study staff.
  • Participation in another investigational clinical study (Jardé 1 or Jardé 2) within 4 weeks before the enrolment visit or still in an exclusion period from another clinical trial or participation in another investigational clinical study planned before the study completion.
  • People under legal protection measure (tutorship, curatorship or safeguard measures)

Trial locations and contacts

11 sites in 1 country.

11 sites in 1 country

France11 sites

  • CIC1412, CHRU Brest

    Brest, 29609

  • Centre de Recherche Clinique, CHU Côte de Nacre

    Caen, 14000

  • CIC 1405 , CHU Clermont-Ferrand

    Clermont-Ferrand, 63000

  • CIC1430, Hôpital Henri Mondor

    Créteil, 94000

  • CIC1413 , Hôtel Dieu - CHU Nantes

    Nantes, 44093

  • Service des maladies infectieuses, CHU de Caremeau

    Nîmes, 30029

  • CIC1417, hôpital Cochin

    Paris, 75 679

  • CIC 1427, Hopital Saint-Louis

    Paris, 75010

  • URCI, Hôpital Lyon Sud

    Pierre-Bénite, 69310

  • CIC1434, Nouvel Hôpital Civil - Hôpitaux Universitaires de Strasbourg

    Strasbourg, 67091

  • CIC1415, CHRU Tours Hôpital Bretonneau

    Tours, 37044

Other trials in France

About this study

Official title: A Phase II Trial Assessing Immunogenicity and Safety of COVID-19 mRNA Vaccine BNT162b2 in Adult Volunteers With no History of SARS-CoV-2 Infection Administered With Two Doses of Vaccine (D1-D29) and in Adult Volunteers With Documented History of SARS-CoV-2 Infection (of More Than 5 Months) Administered With Only One Dose of Vaccine

As previously shown, individuals who experienced COVID-19 have developed some protective immunity to reinfection. The magnitude and duration of protection from reinfection conferred by the infection may be weaker after an asymptomatic infection as it is after a symptomatic COVID-19 episode. Moreover, it is known that immunity decreases among older adults compared to younger individuals often referred to as ''immune senescence,'' and leading to a decreased efficacy of vaccination.

This study raises the question of whether a single administration of BNT162b2 in participants with prior SARS-CoV-2 infection leads to sufficient and durable immune response.

We propose to evaluate the level of the single BNT162b2 vaccine dose response according to the severity of the previous SARS-CoV-2 infection in young and elderly participants with the same immunogenicity analyses to assess this response in participants receiving the two-dose vaccination regimen.

Read the detailed description

This is a national open phase II trial, assessing the immunogenicity and safety of vaccine candidate Pfizer - BNT162b2 against SARS-CoV-2 in participants with no history of SARS-CoV-2 infection receiving two doses of vaccine and in participants with history SARS-CoV-2 infection of more than 5 months and receiving only one dose of vaccine.

A total of 300 volunteers will be included and vaccinated in 2 groups:

Group 1: Adults with no history of SARS-CoV-2 infection(N=150)

  • Sub-group 1A: 18 - 45 years old: 50 volunteers
  • Sub-group 1B: 65 - 74 years old: 50 volunteers* (minimum of 45)
  • Sub-group 1C: At least 75 years old: 50 volunteers* (minimum of 45)

Group 2: Adults with history of SARS-CoV-2 infection of more than 6 months (N=150)

  • Sub-group 2A: 18 - 45 years old: 50 volunteers
  • Sub-groupe 2B : 65 ans et plus: 100 participants

Within each subgroup of the group 2, a distribution will be respected including:

  • 1/3 volunteers with asymptomatic COVID-19 infection,
  • 1/3 volunteers with mild COVID-19 infection ((symptomatic but not hospitalized or hospitalized but no oxygen required) and
  • 1/3 volunteers with severe COVID-19 infection (hospitalization and oxygen required).

Participants within the group 1 will receive BNT162b2 (Comirnaty®) intramuscularly as a 2-dose series spaced 28 days apart at a dose of 30 µg each, then a booster dose (30µg) at M8.

Participants within the group 2 will receive BNT162b2 intramuscularly as a single dose of 30 µg, then a booster dose (30µg) at M8.

Analyses of humorale and saliva immune responses will be performed in differents centralized laboratories blinded for the trial group, by ELISA at Day -6/D0 (pre-vaccination sample), D29, D57, M6, M12, and M24.

T and B cell analyses will be performed in a sub-group of participants Immunosenescence will be analysed in pre-vaccination samples.

Being tested
3 doses of BNT162b2 vaccine, 2 dose of BNT162b2 vaccine
Keywords
BNT162b2 vaccine, elderly, SARS CoV-2 infected participants
Medical subject headings
Infections

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • 3 doses of BNT162b2 vaccineBiological

    Administration of BNT162 b2 vaccine (30µg in 0.3mL) at D1 D29 and M8, intramuscularly (participants without antecedent of SARS-CoV-2 infection)

  • 2 dose of BNT162b2 vaccineBiological

    Administration of BNT162 b2 vaccine (30µg in 0.3mL) at D1 and M8, intramuscularly (participants with antecedent of SARS-CoV-2 infection)

Study groups in NCT04824638
Study groupRoleWhat they receive
Group 1: SARS-CoV-2 naive participantsExperimentalparticipants without antecedent of SARS-CoV-2 infection
Receives: Biological: 3 doses of BNT162b2 vaccine
Group 2: Previously SARS CoV-2 infected participantsExperimentalparticipants with antecedent of SARS-CoV-2 infection (more than 5 months)
Receives: Biological: 2 dose of BNT162b2 vaccine

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. IgG humoral response to vaccine 28 days post vaccination

    Anti SARS-CoV-2 Spike IgG (ELISA test) 28 days after the last injection i.e. at Day 57 in adult volunteers receiving 2 vaccine doses (group 1, without documented history of SARS-CoV-2 infection) and at Day 29 in adult volunteers receiving 1 vaccine dose (group 2, with documented history of SARS-CoV-2 infection).

    Measured: at Day 57 for patients of the group1 and at Day 29 for patient of the group 2

Secondary outcomes (8)

  1. humoral response to vaccine

    Anti SARS-CoV-2 specific IgG at Day1, Day29 (group1), Day57 (group2), [Month8, Month8+3days*, Month8+15 days*, Month8+28 days (participants (*50%)having received the additional vaccine dose)], Month 6, Month8+6months and Month24. Anti SARS-CoV-2 IgA and IgM at Day1, Day29, Day57, Month6, Month8+6months and Month24 (all participants); Month8, Month8+28days (participants that received the additional vaccine dose).Specific neutralizing antibody to SARS-CoV-2 (all participants) and its variants (30 participants per group) by classical in vitro neutralisation assay at Day1, Day29, Day57, Month6, Month8+6months, Month24; Specific neutralizing antibody to SARS-CoV-2 at Month8, Month 8+3days*, Month8+15days* and Month8+28days (participants (*50%) that received the additional vaccine dose). Specific neutralizing antibody to SARS-CoV-2 at day1, Day29, Day57, Month6, Month8+6months, Month24) (all participants). Specific neutralizing antibody to SARS-CoV-2 variants (30 participants per group

    Measured: Day 1, Day 29, Day 57, Month 6, Month 8, Month 8+3days, Month 8+15days, Month 8+28 days, Month 8+6 month, Month 24

  2. T cells response to vaccine

    Fluorospot assays (TH1, TH2, TH17, Cytotoxicity) Phenotyping of antigen specific T-Cells via Mass cytometry at Day 1 and Month24 selected from results of Fluorospot assay

    Measured: Fluorospot assays : Day 1, Day 29, Day 57, Month 6, Month 8+6months, Month 24 (all participants) and at Month 8, Month 8+28days (participants having received the additional vaccine dose). Phenotyping of antigen specific T-Cells : Day 1 and Month 24

  3. Mucosal response to vaccine

    Mucosal SARS-CoV-2 -specific antibody via measure of IgA, IgM and IgG in saliva by specific home-made and commercially available ELISA assays for salivary IgA and IgG

    Measured: Day 1, Day29, Day57, Month6, Month12, Month24 (all participants) [and Month 8, Month 8+28days, Month 8+6months (participants having received the additional vaccine dose)]

  4. B cell response to vaccine

    Determination of the epitope profiling and B Elispots as well as B cell repertoire (stereotype clonotype) of the humoral response

    Measured: Determination of the epitope profiling and B Elispots: Day1, Day57 and Month24. Determination of the B cell repertoire: Day1, Day57 [and Month8, Month8+28days (participants selected for this analysis and having received an additional dose of vaccine]

  5. predictive determinants of vaccine response

    Pre-existing serology for SARS-CoV-2 or other coronavirus, clinical profile of COVID 19 for group 2, immunosenescence profile, transcriptomic analysis, immune cell phenotype

    Measured: at screening visit : (Day -6) and at the latest day (Day 0) before the inclusion visit (Day 1)

  6. Safety of BNT162b2 vaccine

    All grade adverse reactions:

    • Immediate reactogenicity defined as any adverse reactions
    • Local and systemic reactogenicity, all grade, measured by solicited adverse reactions
    • Unsolicited adverse reactions

    Others adverse events:

    • Any AEs of grade ≥ 2, .
    • AEs leading to withdrawal .
    • Medically significant AEs
    • SAEs

    Measured: through 28 days after each dose of vaccine for reactions; throughout the study period (27 months) for others adverse events

  7. SARS-CoV-2 infection

    Occurrence of confirmed SARS-CoV-2 infection.

    Measured: during study period (27 months)

  8. Immunological parameters

    Specific neutralizing antibody to SARS-CoV-2 ; Anti SARS-CoV-2(specific to RBD) by Elisa ; Mucosal SARS-CoV-2 -specific antibody via measure of IgA and IgM in saliva ( ELISA test and specific ultrasensitive test); Fluorospot T cell assays.

    Measured: at the time of the infection to SARS Cov-2 during study period (27 months)

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted1 Apr 2021
  2. Study start8 Mar 2021
  3. Primary completion30 Jun 2021
  4. Study completion2 Dec 2023

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase 2
Primary purpose
Prevention
Allocation
Non-randomised
Intervention model
Parallel groups
Model description
Participants of group 1 will receive two administrations of BNT162b2 at Day1 and Day29 then at Month8 Participants of group 2 will receive one administration of BNT162b2 at Day1, then at Month8
Masking
None (open label)
Enrolment
267 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT04824638
Sponsor's protocol ID
ANRS 0002S CoviCompareP
Other IDs
2021-000509-26
Acronym
CoviCompareP
Status last verified
Dec 2023
First submitted
7 Mar 2021
Last updated
3 Apr 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
Undecided

Questions about this trial

What is this clinical trial studying?

A Phase 2 study testing 3 doses of BNT162b2 vaccine and 2 dose of BNT162b2 vaccine in people with Healthy and Immunization; Infection, run by ANRS, Emerging Infectious Diseases at 11 sites in France.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 10 inclusion and 19 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 3 Apr 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 11 sites in France. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

IgG humoral response to vaccine 28 days post vaccination (time frame: at Day 57 for patients of the group1 and at Day 29 for patient of the group 2). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT04824638.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 3 Apr 2026.

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