ClinicalTrials.gg
CompletedNCT05160766EU-COVAT-1Updated May 20, 2025Results posted

Assessing Immune Response of Different COVID-19 Vaccines in Older Adults

A Phase 2 interventional study of Comirnaty (BTN162b2) and Spikevax (mRNA-1273) in Prevention of COVID-19, sponsored by Oliver Cornely, MD. Completed at 9 sites in 4 countries. Open to participants aged 75 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2025-05-20.

Sponsored by Oliver Cornely, MD · Phase 2, Interventional, and Prevention

Phase
Phase 2
Study type
Interventional
Enrollment
323
Allocation
Randomized
Ages
75 Years and older
Sex
All
01

Study summary

This is a randomised controlled, adaptive, multicentre Phase II protocol evaluating different booster strategies in individuals aged 75 years and older already vaccinated against SARS-CoV-2.

Part A of this trial foresees testing of different vaccines as a 3rd vaccination dose (first booster) for comparative assessment of their immunogenicity and safety against SARS-CoV-2 wild-type and variants in the elderly, a usually neglected population.

Part B of this trial foresees testing of different vaccines as a 4th vaccination dose (second booster) for comparative assessment of their immunogenicity and safety against SARSCoV-2 wild-type and variants in the identical population.

Read the detailed description

Part A of the present trial in which individuals received a 3rd vaccination (first booster) of either BNT162b2 or mRNA-1273 was closed to further recruitment as of January 13, 2022. This was due to a change in vaccination policies, recommending a 3rd vaccination with either BNT162b2 or mRNA-1273. Therefore, Part A was supplanted by Part B that investigated a 4th COVID-19 vaccination and started on 21 Jan 2022.

The initial study protocol started the trial with Part A in which participants were randomized to a 3rd vaccination (first booster) with either BNT162b2 or mRNA-1273:

Subjects who - prior to study entry - received a vaccination series of either BNT162b2 \& BNT162b2 or mRNA-1273 \& mRNA-1273 or ChAdOx-1-S \& ChAdOx-1-S.

For the reasons mentioned above, the study protocol was amended to continue the trial with Part B in which participants were randomized to a 4th vaccination (second booster) with either BNT162b2 or mRNA-1273:

Subjects who - prior to study entry - received a vaccination series of either BNT162b2 \& BNT162b2 \& BNT162b2 or BNT162b2 \& BNT162b2 \& mRNA-1273 or mRNA-1273 \& mRNA-1273 \& mRNA-1273 or mRNA-1273 \& mRNA-1273 \& BNT162b2 or ChAdOx-1-S \& ChAdOx-1-S \& BNT162b2 or ChAdOx-1-S \& ChAdOx-1-S \& mRNA-1273.

02

Conditions studied

  • Prevention of COVID-19

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Keywords

  • SARS-CoV-2
  • COVID-19
  • Vaccination
  • Immunogenicity
  • BNT162b2
  • mRNA-1273
  • Booster
  • Elderly
  • head-to-head comparison
03

In context

COVID-19

7,990 studies on the registry are indexed under COVID-19; 466 are open to participants now.

This study's enrollment of 323 is above the median of 102 across 4,364 interventional studies indexed under COVID-19.

Browse COVID-19 studies →

Lead sponsor

Oliver Cornely, MD is the lead sponsor of 3 studies on the registry; 1 is open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
75 Years and older
Sexes eligible
All
Accepts healthy volunteers
Yes

Eligibility criteria

Inclusion Criteria (Part A):

  • Subject is ≥75 years old.
  • Prior to study entry the subject was vaccinated with BNT162b2, mRNA-1273 or ChAdOx-1-S (same vaccine product for 1st + 2nd dose)

BNT162b2 + BNT162b2

mRNA-1273 + mRNA-1273

ChAdOx-1-S + ChAdOx-1-S

  • 9 ± 3 months since the second vaccine dose at time of enrolment for the planned 3rd vaccine dose in the trial. Vaccination status should be documented in the source data and captured in the eCRF.
  • No against any of the vaccine products in the trial.
  • Written from subject has been obtained.

Exclusion Criteria (Part A):

  • Primary vaccination performed with different vaccine products as sole (e.g., COVID-19 Vaccine Janssen) or, 1st and 2nd vaccination doses (heterologous vaccination scheme).
  • Subjects with any significant or uncontrolled disease posing a risk due to vaccination as judged by the investigator.
  • Current therapy, for example continuous glucocorticosteroid treatment equivalent to >10 mg/day prednisolone.
  • Participation in other interventional trials.
  • Subjects unable to report solicited adverse events.
  • Subject with any contraindications to the vaccines in the trial at randomisation. A list of contraindications as listed in the Summary of medicinal Product Characteristics (SmPC, the Fachinformation in Germany), if appropriate.
  • Use of drugs with significant interaction with the product according to the SmPC or similar documents.
  • Diseases or findings that may have a significant effect on the target variables and which may therefore mask or inhibit the therapeutic effect under investigation.
  • Any current SARS-CoV-2 infection or proven in the preceding 3 months.
  • Persons with any kind of dependency on the principal investigator or employed by the sponsor or principal investigator.
  • Legally incapacitated persons.
  • Persons held in an institution by legal or official order.

Inclusion Criteria (Part B):

  • Subject is ≥75 years old.
  • Prior to study entry the subject was vaccinated with one of the following vaccination regimens (1st + 2nd + 3rd dose):

BNT162b2 + BNT162b2 + BNT162b2

BNT162b2 + BNT162b2 + mRNA-1273

mRNA-1273 + mRNA-1273 + mRNA-1273

mRNA-1273 + mRNA-1273 + BNT162b2

ChAdOx-1-S + ChAdOx-1-S + BNT162b2

ChAdOx-1-S + ChAdOx-1-S + mRNA-1273

The last dose of the above listed vaccinations must have been administered at least 1 month prior to study entry. Vaccination status should be documented in the source data and will be captured in the eCRF.

  • Written informed consent from subject has been obtained.

Exclusion Criteria (Part B):

  • Prior to study entry the subject got vaccinated with a regimen not included in the list given above.
  • Last anti-SARS-CoV-2 vaccine dose administered less than one month prior to study entry.
  • Vaccination against a disease other than COVID-19 within 2 weeks prior to study entry. Only exception: Influenza vaccination which is allowed at any time.
  • Subjects with any significant or uncontrolled disease posing a risk due to vaccination as judged by the investigator.
  • Current immunosuppressive therapy, for example continuous glucocorticosteroid treatment equivalent to >10 mg/day prednisolone.
  • Subject simultaneously participates in another clinical trials or has participated in the past 30 days.
  • Subjects unable to report solicited adverse events.
  • Subject with any contraindications to the vaccines in the trial. A list of contraindications as listed in the Summary of medicinal Product Characteristics (SmPC, the Fachinformation in Germany), if appropriate.
Terms in these criteria, in plain language(4)

Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.

Contraindication

A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.

Informed consent

Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.

You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.

Immunosuppression

A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.

Read whether the line is about a condition or about medicines, and which medicines and doses it means.

Investigational drug or device

A drug or device being studied in a clinical trial.

It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.

05

Study design

Phase
Phase 2
Primary purpose
Prevention
Allocation
Randomized
Intervention model
Parallel assignment
Masking
None (open label)
Enrollment
323 participants (actual)

Study arms

  • Active comparator
    BNT162b2 (Part A)

    vaccination with BNT162b2 as 3rd vaccination

    Biological: Comirnaty (BTN162b2)

  • Active comparator
    mRNA-1273 (Part A)

    vaccination with mRNA-1273 as 3rd vaccination

    Biological: Spikevax (mRNA-1273)

  • Active comparator
    BNT162b2 (Part B)

    vaccination with BNT162b2 as 4th vaccination

    Biological: Comirnaty (BTN162b2)

  • Active comparator
    mRNA-1273 (Part B)

    vaccination with mRNA-1273 as 4th vaccination

    Biological: Spikevax (mRNA-1273)

Interventions

06

What researchers measure

Primary outcomes

  1. Antibody Titre Increase 14 Days After Study Vaccination Dose.

    Rate of 2-fold antibody titre increase 14 days after 3rd (Part A) or 4th vaccination dose (Part B) measured by qualitative enzyme-linked immunosorbent assay (Anti-RBD-ELISA) against wildtype virus.

    Time frame: From Day 0 until Day 14

Secondary outcomes

  1. Change in Neutralizing Antibody Titre Against Wild-type 14 Days After Study Vaccination Dose

    Change in neutralizing antibody titre (Virus Neutralisation Assay) against wild-type 14 days after a 3rd (Part A) or 4th vaccination dose (Part B), to be determined in a subgroup only. Microneutralization assay results were proposed to be reported as "change in neutralizing antibody titre (Virus Neutralisation Assay)" in the trial protocol. However, as the pandemic progressed, the need arose to assess neutralization against different variants. In our stud(ies), we evaluated not only the Wuhan strain but also 25 distinct variants of concern (VoCs) and/or variants of interest (VoIs). For VoCs and VoIs, expressing results as "change in neutralization capacity expressed as a percentage (%)" is more effective as it illustrates the impact of mutations on neutralization, thereby allowing cross-variant comparisons. This adjustment did not alter the suggested endpoint, as both reporting methods reflect the ability of patients' antibodies neutralizing capacities.

    Time frame: From Day 0 until Day 14

  2. Change in Neutralizing Antibody Titre Against Variants of Concern 14 Days After Study Vaccination Dose

    Change in neutralizing antibody titre (Virus Neutralisation Assay) against variants of concern 14 days after a 3rd (Part A) or 4th vaccination dose (Part B), to be determined in a subgroup only. Microneutralization assay results were proposed to be reported as "change in neutralizing antibody titre (Virus Neutralisation Assay)" in the trial protocol. However, as the pandemic progressed, the need arose to assess neutralization against different variants. In our stud(ies), we evaluated not only the Wuhan strain but also 25 distinct variants of concern (VoCs) and/or variants of interest (VoIs). For VoCs and VoIs, expressing results as "change in neutralization capacity expressed as a percentage (%)" is more effective as it illustrates the impact of mutations on neutralization, thereby allowing cross-variant comparisons. This adjustment did not alter the suggested endpoint, as both reporting methods reflect the ability of patients' antibodies neutralizing capacities.

    Time frame: From Day 0 until Day 14

  3. Antibody Titre Level at 12 Months After a Study Vaccination Dose

    Antibody titre level at 12 months after a 3rd (Part A) or 4th vaccination dose (Part B) measured by a quantitative enzyme-linked immunosorbent assay (anti-RBD-ELISA assay).

    Time frame: From Day 0 until Month 12

  4. Neutralizing Antibody Titre Against Wild-type at 12 Months After Study Vaccination Dose

    Neutralizing antibody titre (Virus Neutralisation Assay) against wild-type SARS-CoV-2 at 12 months after a 3rd (Part A) or 4th vaccination dose (Part B), to be determined in a subgroup only. Microneutralization assay results were proposed to be reported as "change in neutralizing antibody titre (Virus Neutralisation Assay)" in the trial protocol. However, as the pandemic progressed, the need arose to assess neutralization against different variants. In our stud(ies), we evaluated not only the Wuhan strain but also 25 distinct variants of concern (VoCs) and/or variants of interest (VoIs). For VoCs and VoIs, expressing results as "change in neutralization capacity expressed as a percentage (%)" is more effective as it illustrates the impact of mutations on neutralization, thereby allowing cross-variant comparisons. This adjustment did not alter the suggested endpoint, as both reporting methods reflect the ability of patients' antibodies neutralizing capacities.

    Time frame: From Day 0 until Month 12

  5. Neutralizing Antibody Titre Against Variants of Concern at 12 Months After Study Vaccination Dose

    Neutralizing antibody titre (Virus Neutralisation Assay) against variants of concern at 12 months after a 3rd (Part A) or 4th vaccination dose (Part B), to be determined in a subgroup only. Microneutralization assay results were proposed to be reported as "change in neutralizing antibody titre (Virus Neutralisation Assay)" in the trial protocol. However, as the pandemic progressed, the need arose to assess neutralization against different variants. In our stud(ies), we evaluated not only the Wuhan strain but also 25 distinct variants of concern (VoCs) and/or variants of interest (VoIs). For VoCs and VoIs, expressing results as "change in neutralization capacity expressed as a percentage (%)" is more effective as it illustrates the impact of mutations on neutralization, thereby allowing cross-variant comparisons. This adjustment did not alter the suggested endpoint, as both reporting methods reflect the ability of patients' antibodies neutralizing capacities.

    Time frame: From Day 0 until Month 12

Other outcomes

  1. Number of Participants With Unsolicited AEs

    Number of Participants with Unsolicited AEs until the end of trial

    Time frame: From Day 0 until Month 12

  2. Number of Participants With Solicited AEs

    Number of Participants with Solicited AEs for 7 days after study vaccination dose.

    Time frame: From Day 0 until Day 7

  3. Number of Participants With Rate of SAEs Grade ≥3

    Number of Participants with Rate of serious adverse events (SAEs) Grade ≥3 according to the National Cancer Institute Common Toxicity Criteria up to three months after study vaccination dose.

    Time frame: From Day 0 until Month 3

  4. Change in Cellular Immune Response Measured by qPCR 14 Days After 4th Vaccination Dose

    Change in cellular immune response (CD4+ and CD8+ T cell response) to SARS-CoV-2 measured by fold change of CXCL10 mRNA levels measured by qPCR after 4th vaccination dose, to be determined in a subgroup only.

    Time frame: From Day 0 until Day 14

  5. Neutralizing Antibody Titre Against Newly Emerging Variants in Bio-banked Samples After Study Vaccination Dose

    "Neutralizing antibody titre (Virus Neutralisation Assay)" against newly emerging variants in bio-banked samples after a 3rd (Part A) or 4th vaccination dose (Part B), to be determined in a subgroup only. Microneutralization assay results were proposed to be reported as "change in neutralizing antibody titre (Virus Neutralisation Assay)" in the trial protocol. However, as the pandemic progressed, the need arose to assess neutralization against different variants. In our stud(ies), we evaluated not only the Wuhan strain but also 25 distinct variants of concern (VoCs) and/or variants of interest (VoIs). For VoCs and VoIs, expressing results as "change in neutralization capacity expressed as a percentage (%)" is more effective as it illustrates the impact of mutations on neutralization, thereby allowing cross-variant comparisons. This adjustment did not alter the suggested endpoint, as both reporting methods reflect the ability of patients' antibodies neutralizing capacities.

    Time frame: From Day 0 until Month 12

07

Results

Posted May 20, 2025

Participant flow

Participant flow — Overall Study
MilestoneBNT162b2 (Part A)mRNA-1273 (Part A)BTN162b2 (Part B)mRNA-1273 (Part B)
Started2527135135
Completed2120126123
Not completed47912
Withdrew: Adverse event0100
Withdrew: Covid-19 infection0100
Withdrew: Travel time1001
Withdrew: Withdrawal by subject3542
Withdrew: Death0025
Withdrew: Lost to follow-up0012
Withdrew: No show0011
Withdrew: Physician decision0001
Withdrew: Protocol violation0010

Outcome measures

PrimaryAntibody Titre Increase 14 Days After Study Vaccination Dose.

Rate of 2-fold antibody titre increase 14 days after 3rd (Part A) or 4th vaccination dose (Part B) measured by qualitative enzyme-linked immunosorbent assay (Anti-RBD-ELISA) against wildtype virus.

Time frame:
From Day 0 until Day 14
Reported as:
Number · percentage of participants
Antibody Titre Increase 14 Days After Study Vaccination Dose.
percentage of participantsBNT162b2 (Part A)mRNA-1273 (Part A)BNT162b2 (Part B)mRNA-1273 (Part B)
Antibody Titre Increase 14 Days After Study Vaccination Dose.100 (83.9 to 100)100 (83.9 to 100)78.46 (69.2 to 86)87.22 (79.3 to 93)
SecondaryChange in Neutralizing Antibody Titre Against Wild-type 14 Days After Study Vaccination Dose

Change in neutralizing antibody titre (Virus Neutralisation Assay) against wild-type 14 days after a 3rd (Part A) or 4th vaccination dose (Part B), to be determined in a subgroup only. Microneutralization assay results were proposed to be reported as "change in neutralizing antibody titre (Virus Neutralisation Assay)" in the trial protocol. However, as the pandemic progressed, the need arose to assess neutralization against different variants. In our stud(ies), we evaluated not only the Wuhan strain but also 25 distinct variants of concern (VoCs) and/or variants of interest (VoIs). For VoCs and VoIs, expressing results as "change in neutralization capacity expressed as a percentage (%)" is more effective as it illustrates the impact of mutations on neutralization, thereby allowing cross-variant comparisons. This adjustment did not alter the suggested endpoint, as both reporting methods reflect the ability of patients' antibodies neutralizing capacities.

Time frame:
From Day 0 until Day 14
Reported as:
Mean · percentage of inhibition
Change in Neutralizing Antibody Titre Against Wild-type 14 Days After Study Vaccination Dose
percentage of inhibitionBTN162b2 (Part A)mRNA-1273 (Part A)BTN162b2 (Part B)mRNA-1273 (Part B)
Change in Neutralizing Antibody Titre Against Wild-type 14 Days After Study Vaccination Dose58.49 ± 16.2565.98 ± 18.3237.33 ± 22.9341.45 ± 24.09
Statistical analysis
  • BTN162b2 (Part A) vs mRNA-1273 (Part A) · ANCOVA · p = 0.03143 · Difference of means in percent: 12.557 · 95% CI 1.168 to 23.946
  • BTN162b2 (Part B) vs mRNA-1273 (Part B) · ANCOVA · p = 0.0101 · Difference of means in percent: 4.331 · 95% CI 1.04 to 7.621
SecondaryChange in Neutralizing Antibody Titre Against Variants of Concern 14 Days After Study Vaccination Dose

Change in neutralizing antibody titre (Virus Neutralisation Assay) against variants of concern 14 days after a 3rd (Part A) or 4th vaccination dose (Part B), to be determined in a subgroup only. Microneutralization assay results were proposed to be reported as "change in neutralizing antibody titre (Virus Neutralisation Assay)" in the trial protocol. However, as the pandemic progressed, the need arose to assess neutralization against different variants. In our stud(ies), we evaluated not only the Wuhan strain but also 25 distinct variants of concern (VoCs) and/or variants of interest (VoIs). For VoCs and VoIs, expressing results as "change in neutralization capacity expressed as a percentage (%)" is more effective as it illustrates the impact of mutations on neutralization, thereby allowing cross-variant comparisons. This adjustment did not alter the suggested endpoint, as both reporting methods reflect the ability of patients' antibodies neutralizing capacities.

Time frame:
From Day 0 until Day 14
Reported as:
Mean · percentage of inhibition
Change in Neutralizing Antibody Titre Against Variants of Concern 14 Days After Study Vaccination Dose
percentage of inhibitionBNT162b2 (Part A)mRNA-1273 (Part A)BNT162b2 (Part B)mRNA-1273 (Part B)
Change in Neutralizing Antibody Titre Against Variants of Concern 14 Days After Study Vaccination Dose49.86 ± 17.6257.39 ± 19.7738.17 ± 21.7444.04 ± 23.94
Statistical analysis
  • BNT162b2 (Part A) vs mRNA-1273 (Part A) · ANCOVA · p = 0.04405 · Difference of means in percent: 12.168 · 95% CI 0.338 to 23.998
  • BNT162b2 (Part A) vs mRNA-1273 (Part A) · ANCOVA · p = 0.01744 · Difference of means in percent: 14.212 · 95% CI 2.61 to 25.814
  • BNT162b2 (Part A) vs mRNA-1273 (Part A) · ANCOVA · p = 0.02039 · Difference of means in percent: 14.239 · 95% CI 2.305 to 26.173
  • BNT162b2 (Part A) vs mRNA-1273 (Part A) · ANCOVA · p = 0.04989 · Difference of means in percent: 9.331 · 95% CI 0.005 to 18.656
  • BNT162b2 (Part A) vs mRNA-1273 (Part A) · ANCOVA · p = 0.02259 · Difference of means in percent: 10.312 · 95% CI 1.514 to 19.111
  • BNT162b2 (Part A) vs mRNA-1273 (Part A) · ANCOVA · p = 0.01583 · Difference of means in percent: 11.601 · 95% CI 2.279 to 20.924
  • BNT162b2 (Part A) vs mRNA-1273 (Part A) · ANCOVA · p = 0.00856 · Difference of means in percent: 11.863 · 95% CI 3.166 to 20.56
  • BNT162b2 (Part B) vs mRNA-1273 (Part B) · ANCOVA · p = 0.00258 · Difference of means in percent: 6.83 · 95% CI 2.41 to 11.249
  • BNT162b2 (Part B) vs mRNA-1273 (Part B) · ANCOVA · p = 0.00748 · Difference of means in percent: 6.048 · 95% CI 1.63 to 10.466
  • BNT162b2 (Part B) vs mRNA-1273 (Part B) · ANCOVA · p = 0.00922 · Difference of means in percent: 7.302 · 95% CI 1.821 to 12.782
  • BNT162b2 (Part B) vs mRNA-1273 (Part B) · ANCOVA · p = 0.07136 · Difference of means in percent: 4.791 · 95% CI -0.419 to 10.001
  • BNT162b2 (Part B) vs mRNA-1273 (Part B) · ANCOVA · p = 0.07218 · Difference of means in percent: 3.965 · 95% CI -0.36 to 8.29
  • BNT162b2 (Part B) vs mRNA-1273 (Part B) · ANCOVA · p = 0.02949 · Difference of means in percent: 4.82 · 95% CI 0.484 to 9.155
  • BNT162b2 (Part B) vs mRNA-1273 (Part B) · ANCOVA · p = 0.08403 · Difference of means in percent: 3.926 · 95% CI -0.531 to 8.382
SecondaryAntibody Titre Level at 12 Months After a Study Vaccination Dose

Antibody titre level at 12 months after a 3rd (Part A) or 4th vaccination dose (Part B) measured by a quantitative enzyme-linked immunosorbent assay (anti-RBD-ELISA assay).

Time frame:
From Day 0 until Month 12
Reported as:
Geometric mean · IU/ml
Antibody Titre Level at 12 Months After a Study Vaccination Dose
IU/mlBTN162b2 (Part A)mRNA-1273 (Part A)BNT162b2 (Part B)mRNA-1273 (Part B)
Antibody Titre Level at 12 Months After a Study Vaccination Dose9319.7 ± 25896.2714163.81 ± 46209.359961.92 ± 26292.2312024.3 ± 29129.18
SecondaryNeutralizing Antibody Titre Against Wild-type at 12 Months After Study Vaccination Dose

Neutralizing antibody titre (Virus Neutralisation Assay) against wild-type SARS-CoV-2 at 12 months after a 3rd (Part A) or 4th vaccination dose (Part B), to be determined in a subgroup only. Microneutralization assay results were proposed to be reported as "change in neutralizing antibody titre (Virus Neutralisation Assay)" in the trial protocol. However, as the pandemic progressed, the need arose to assess neutralization against different variants. In our stud(ies), we evaluated not only the Wuhan strain but also 25 distinct variants of concern (VoCs) and/or variants of interest (VoIs). For VoCs and VoIs, expressing results as "change in neutralization capacity expressed as a percentage (%)" is more effective as it illustrates the impact of mutations on neutralization, thereby allowing cross-variant comparisons. This adjustment did not alter the suggested endpoint, as both reporting methods reflect the ability of patients' antibodies neutralizing capacities.

Time frame:
From Day 0 until Month 12
Reported as:
Mean · percentage of inhibition
Neutralizing Antibody Titre Against Wild-type at 12 Months After Study Vaccination Dose
percentage of inhibitionBNT162b2 (Part A)mRNA-1273 (Part A)BNT162b2 (Part B)mRNA-1273 (Part B)
Neutralizing Antibody Titre Against Wild-type at 12 Months After Study Vaccination Dose54.5 ± 33.6462.65 ± 33.2612.93 ± 39.2918.15 ± 33.24
SecondaryNeutralizing Antibody Titre Against Variants of Concern at 12 Months After Study Vaccination Dose

Neutralizing antibody titre (Virus Neutralisation Assay) against variants of concern at 12 months after a 3rd (Part A) or 4th vaccination dose (Part B), to be determined in a subgroup only. Microneutralization assay results were proposed to be reported as "change in neutralizing antibody titre (Virus Neutralisation Assay)" in the trial protocol. However, as the pandemic progressed, the need arose to assess neutralization against different variants. In our stud(ies), we evaluated not only the Wuhan strain but also 25 distinct variants of concern (VoCs) and/or variants of interest (VoIs). For VoCs and VoIs, expressing results as "change in neutralization capacity expressed as a percentage (%)" is more effective as it illustrates the impact of mutations on neutralization, thereby allowing cross-variant comparisons. This adjustment did not alter the suggested endpoint, as both reporting methods reflect the ability of patients' antibodies neutralizing capacities.

Time frame:
From Day 0 until Month 12
Reported as:
Mean · percentage of inhibition
Neutralizing Antibody Titre Against Variants of Concern at 12 Months After Study Vaccination Dose
percentage of inhibitionBNT162b2 (Part A)mRNA-1273 (Part A)BNT162b2 (Part B)mRNA-1273 (Part B)
Neutralizing Antibody Titre Against Variants of Concern at 12 Months After Study Vaccination Dose40.59 ± 35.3749 ± 36.3715.76 ± 38.420.24 ± 37.24
Statistical analysis
  • BNT162b2 (Part A) vs mRNA-1273 (Part A) · ANCOVA · p = 0.42797 · Difference of means in percent: 8.835 · 95% CI -13.475 to 31.145
  • BNT162b2 (Part A) vs mRNA-1273 (Part A) · ANCOVA · p = 0.73961 · Difference of means in percent: 3.54 · 95% CI -17.85 to 24.929
  • BNT162b2 (Part A) vs mRNA-1273 (Part A) · ANCOVA · p = 0.45370 · Difference of means in percent: 8.086 · 95% CI -13.524 to 29.695
  • BNT162b2 (Part A) vs mRNA-1273 (Part A) · ANCOVA · p = 0.87323 · Difference of means in percent: 1.636 · 95% CI -18.969 to 22.241
  • BNT162b2 (Part A) vs mRNA-1273 (Part A) · ANCOVA · p = 0.93489 · Difference of means in percent: 0.81 · 95% CI -19.109 to 20.728
  • BNT162b2 (Part A) vs mRNA-1273 (Part A) · ANCOVA · p = 0.74784 · Difference of means in percent: 3.511 · 95% CI -18.425 to 25.448
  • BNT162b2 (Part A) vs mRNA-1273 (Part A) · ANCOVA · p = 0.84202 · Difference of means in percent: 2.088 · 95% CI -18.966 to 23.143
  • BNT162b2 (Part B) vs mRNA-1273 (Part B) · ANCOVA · p = 0.15477 · Difference of means in percent: 5.807 · 95% CI -2.207 to 13.821
  • BNT162b2 (Part B) vs mRNA-1273 (Part B) · ANCOVA · p = 0.37773 · Difference of means in percent: 3.52 · 95% CI -4.327 to 11.368
  • BNT162b2 (Part B) vs mRNA-1273 (Part B) · ANCOVA · p = 0.29212 · Difference of means in percent: 4.413 · 95% CI -3.821 to 12.647
  • BNT162b2 (Part B) vs mRNA-1273 (Part B) · ANCOVA · p = 0.14140 · Difference of means in percent: 5.961 · 95% CI -1.998 to 13.919
  • BNT162b2 (Part B) vs mRNA-1273 (Part B) · ANCOVA · p = 0.57090 · Difference of means in percent: 2.199 · 95% CI -5.434 to 9.832
  • BNT162b2 (Part B) vs mRNA-1273 (Part B) · ANCOVA · p = 0.11012 · Difference of means in percent: 6.528 · 95% CI -1.491 to 14.548
  • BNT162b2 (Part B) vs mRNA-1273 (Part B) · ANCOVA · p = 0.29755 · Difference of means in percent: 4.239 · 95% CI -3.759 to 12.237
Other pre-specifiedNumber of Participants With Unsolicited AEs

Number of Participants with Unsolicited AEs until the end of trial

Time frame:
From Day 0 until Month 12
Reported as:
Count of participants · Participants
Number of Participants With Unsolicited AEs
ParticipantsBNT162b2 (Part A)mRNA-1273 (Part A)BNT162b2 (Part B)mRNA-1273 (Part B)
Number of Participants With Unsolicited AEs2226110112
Other pre-specifiedNumber of Participants With Solicited AEs

Number of Participants with Solicited AEs for 7 days after study vaccination dose.

Time frame:
From Day 0 until Day 7
Reported as:
Count of participants · Participants
Number of Participants With Solicited AEs
ParticipantsBNT162b2 (Part A)mRNA-1273 (Part A)BNT162b2 (Part B)mRNA-1273 (Part B)
Number of Participants With Solicited AEs20257680
Other pre-specifiedNumber of Participants With Rate of SAEs Grade ≥3

Number of Participants with Rate of serious adverse events (SAEs) Grade ≥3 according to the National Cancer Institute Common Toxicity Criteria up to three months after study vaccination dose.

Time frame:
From Day 0 until Month 3
Reported as:
Count of participants · Participants
Number of Participants With Rate of SAEs Grade ≥3
ParticipantsBNT162b2 (Part A)mRNA-1273 (Part A)BNT162b2 (Part B)mRNA-1273 (Part B)
Number of Participants With Rate of SAEs Grade ≥30010
Other pre-specifiedChange in Cellular Immune Response Measured by qPCR 14 Days After 4th Vaccination Dose

Change in cellular immune response (CD4+ and CD8+ T cell response) to SARS-CoV-2 measured by fold change of CXCL10 mRNA levels measured by qPCR after 4th vaccination dose, to be determined in a subgroup only.

Time frame:
From Day 0 until Day 14
Reported as:
Mean · Fold change of CXCL10 mRNA levels
Change in Cellular Immune Response Measured by qPCR 14 Days After 4th Vaccination Dose
Fold change of CXCL10 mRNA levelsBNT162b2mRNA-1273
Change in Cellular Immune Response Measured by qPCR 14 Days After 4th Vaccination Dose26.63 ± 1.5826.63 ± 1.59
Other pre-specifiedNeutralizing Antibody Titre Against Newly Emerging Variants in Bio-banked Samples After Study Vaccination Dose

"Neutralizing antibody titre (Virus Neutralisation Assay)" against newly emerging variants in bio-banked samples after a 3rd (Part A) or 4th vaccination dose (Part B), to be determined in a subgroup only. Microneutralization assay results were proposed to be reported as "change in neutralizing antibody titre (Virus Neutralisation Assay)" in the trial protocol. However, as the pandemic progressed, the need arose to assess neutralization against different variants. In our stud(ies), we evaluated not only the Wuhan strain but also 25 distinct variants of concern (VoCs) and/or variants of interest (VoIs). For VoCs and VoIs, expressing results as "change in neutralization capacity expressed as a percentage (%)" is more effective as it illustrates the impact of mutations on neutralization, thereby allowing cross-variant comparisons. This adjustment did not alter the suggested endpoint, as both reporting methods reflect the ability of patients' antibodies neutralizing capacities.

Time frame:
From Day 0 until Month 12
Reported as:
Mean · percentage of inhibition
Neutralizing Antibody Titre Against Newly Emerging Variants in Bio-banked Samples After Study Vaccination Dose
percentage of inhibitionBNT162b2 (Part A)mRNA-1273 (Part A)BNT162b2 (Part B)mRNA-1273 (Part B)
Neutralizing Antibody Titre Against Newly Emerging Variants in Bio-banked Samples After Study Vaccination Dose19.28 ± 30.9427.18 ± 28.1416.75 ± 34.2419.03 ± 33.01
Statistical analysis
  • BNT162b2 (Part A) vs mRNA-1273 (Part A) · ANCOVA · p = 0.39426 · Difference of means in percent: 9.64 · 95% CI -12.995 to 32.275
  • BNT162b2 (Part A) vs mRNA-1273 (Part A) · ANCOVA · p = 0.42055 · Difference of means in percent: 8.764 · 95% CI -13.011 to 30.539
  • BNT162b2 (Part A) vs mRNA-1273 (Part A) · ANCOVA · p = 0.44391 · Difference of means in percent: 8.472 · 95% CI -13.683 to 30.627
  • BNT162b2 (Part A) vs mRNA-1273 (Part A) · ANCOVA · p = 0.43775 · Difference of means in percent: 8.483 · 95% CI -13.402 to 30.368
  • BNT162b2 (Part A) vs mRNA-1273 (Part A) · ANCOVA · p = 0.53511 · Difference of means in percent: 6.19 · 95% CI -13.819 to 26.2
  • BNT162b2 (Part A) vs mRNA-1273 (Part A) · ANCOVA · p = 0.67576 · Difference of means in percent: 4.552 · 95% CI -17.295 to 26.399
  • BNT162b2 (Part A) vs mRNA-1273 (Part A) · ANCOVA · p = 0.45443 · Difference of means in percent: 8.438 · 95% CI -14.15 to 31.027
  • BNT162b2 (Part A) vs mRNA-1273 (Part A) · ANCOVA · p = 0.38904 · Difference of means in percent: 8.901 · 95% CI -11.768 to 29.569
  • BNT162b2 (Part A) vs mRNA-1273 (Part A) · ANCOVA · p = 0.47466 · Difference of means in percent: 7.302 · 95% CI -13.147 to 27.751
  • BNT162b2 (Part A) vs mRNA-1273 (Part A) · ANCOVA · p = 0.77110 · Difference of means in percent: 2.878 · 95% CI -16.993 to 22.749
  • BNT162b2 (Part A) vs mRNA-1273 (Part A) · ANCOVA · p = 0.86646 · Difference of means in percent: 1.753 · 95% CI -19.195 to 22.701
  • BNT162b2 (Part A) vs mRNA-1273 (Part A) · ANCOVA · p = 0.57972 · Difference of means in percent: 5.42 · 95% CI -14.21 to 25.049
  • BNT162b2 (Part A) vs mRNA-1273 (Part A) · ANCOVA · p = 0.90166 · Difference of means in percent: 1.17 · 95% CI -17.859 to 20.199
  • BNT162b2 (Part A) vs mRNA-1273 (Part A) · ANCOVA · p = 0.92279 · Difference of means in percent: 1.018 · 95% CI -20.099 to 22.136
  • BNT162b2 (Part A) vs mRNA-1273 (Part A) · ANCOVA · p = 0.71191 · Difference of means in percent: 3.532 · 95% CI -15.675 to 22.74
  • BNT162b2 (Part A) vs mRNA-1273 (Part A) · ANCOVA · p = 0.73415 · Difference of means in percent: 2.995 · 95% CI -14.714 to 20.703
  • BNT162b2 (Part A) vs mRNA-1273 (Part A) · ANCOVA · p = 0.45798 · Difference of means in percent: 7.157 · 95% CI -12.155 to 26.469
  • BNT162b2 (Part B) vs mRNA-1273 (Part B) · ANCOVA · p = 0.23582 · Difference of means in percent: 4.819 · 95% CI -3.169 to 12.808
  • BNT162b2 (Part B) vs mRNA-1273 (Part B) · ANCOVA · p = 0.19354 · Difference of means in percent: 5.312 · 95% CI -2.713 to 13.337
  • BNT162b2 (Part B) vs mRNA-1273 (Part B) · ANCOVA · p = 0.17033 · Difference of means in percent: 5.714 · 95% CI -2.471 to 13.899
  • BNT162b2 (Part B) vs mRNA-1273 (Part B) · ANCOVA · p = 0.13895 · Difference of means in percent: 5.934 · 95% CI -1.94 to 13.808
  • BNT162b2 (Part B) vs mRNA-1273 (Part B) · ANCOVA · p = 0.26924 · Difference of means in percent: 4.222 · 95% CI -3.288 to 11.732
  • BNT162b2 (Part B) vs mRNA-1273 (Part B) · ANCOVA · p = 0.17080 · Difference of means in percent: 5.49 · 95% CI -2.382 to 13.362
  • BNT162b2 (Part B) vs mRNA-1273 (Part B) · ANCOVA · p = 0.18502 · Difference of means in percent: 5.567 · 95% CI -2.683 to 13.818
  • BNT162b2 (Part B) vs mRNA-1273 (Part B) · ANCOVA · p = 0.38344 · Difference of means in percent: 3.438 · 95% CI -4.318 to 11.195
  • BNT162b2 (Part B) vs mRNA-1273 (Part B) · ANCOVA · p = 0.41100 · Difference of means in percent: 3.279 · 95% CI -4.565 to 11.124
  • BNT162b2 (Part B) vs mRNA-1273 (Part B) · ANCOVA · p = 0.50660 · Difference of means in percent: 2.67 · 95% CI -5.237 to 10.577
  • BNT162b2 (Part B) vs mRNA-1273 (Part B) · ANCOVA · p = 0.28604 · Difference of means in percent: 4.535 · 95% CI -3.82 to 12.891
  • BNT162b2 (Part B) vs mRNA-1273 (Part B) · ANCOVA · p = 0.11715 · Difference of means in percent: 6.259 · 95% CI -1.582 to 14.1
  • BNT162b2 (Part B) vs mRNA-1273 (Part B) · ANCOVA · p = 0.33567 · Difference of means in percent: 3.818 · 95% CI -3.978 to 11.613
  • BNT162b2 (Part B) vs mRNA-1273 (Part B) · ANCOVA · p = 0.15232 · Difference of means in percent: 5.775 · 95% CI -2.147 to 13.697
  • BNT162b2 (Part B) vs mRNA-1273 (Part B) · ANCOVA · p = 0.21234 · Difference of means in percent: 4.808 · 95% CI -2.766 to 12.383
  • BNT162b2 (Part B) vs mRNA-1273 (Part B) · ANCOVA · p = 0.22687 · Difference of means in percent: 4.58 · 95% CI -2.866 to 12.026
  • BNT162b2 (Part B) vs mRNA-1273 (Part B) · ANCOVA · p = 0.38832 · Difference of means in percent: 3.498 · 95% CI -4.475 to 11.47

Adverse events

Collected over AEs were documented starting from baseline visit (Day 0) and until the last scheduled visit after the study vaccine dose (Month 12).. Non-serious events are listed at a 0% frequency threshold.

Adverse event summary by group
GroupDeathsSeriousOther
BNT162b2 (Part A)0/25 (0%)0/25 (0%)20/25 (80%)
mRNA-1273 (Part A)0/27 (0%)0/27 (0%)25/27 (92.6%)
BNT162b2 (Part B)2/135 (1.5%)21/135 (15.6%)103/135 (76.3%)
mRNA-1273 (Part B)5/135 (3.7%)22/135 (16.3%)110/135 (81.5%)
Most frequent serious events
Showing 10 of 58
Most frequent serious events
EventBNT162b2 (Part A)mRNA-1273 (Part A)BNT162b2 (Part B)mRNA-1273 (Part B)
Atrial fibrillationCardiac disorders——1/1353/135
PneumoniaInfections and infestations——3/1350/135
Transient ischaemic attackNervous system disorders——0/1353/135
Cardiac failureCardiac disorders——0/1352/135
Lower respiratory tract infectionInfections and infestations——2/1351/135
UrosepsisInfections and infestations——2/1350/135
Acute myocardial infarctionCardiac disorders——1/1350/135
Angina pectorisCardiac disorders——1/1350/135
ArrhythmiaCardiac disorders——0/1351/135
Atrioventricular blockCardiac disorders——1/1350/135
Most frequent other events
Showing 10 of 153
Most frequent other events
EventBNT162b2 (Part A)mRNA-1273 (Part A)BNT162b2 (Part B)mRNA-1273 (Part B)
Injection site discomfortGastrointestinal disorders8/2515/270/1350/135
FatigueGeneral disorders7/2514/2731/13551/135
Injection site painGeneral disorders7/255/2754/13559/135
Injection site indurationGeneral disorders6/2510/271/1350/135
Pain in extremityMusculoskeletal and connective tissue disorders0/250/2734/13540/135
Injection site swellingGeneral disorders2/257/2710/13515/135
MyalgiaMusculoskeletal and connective tissue disorders1/257/277/13511/135
COVID-19Infections and infestations0/250/2731/13531/135
ArthralgiaMusculoskeletal and connective tissue disorders2/256/276/1358/135
ChillsGeneral disorders1/255/276/1358/135

Baseline characteristics

Age, Continuous
Age, Continuous(years)BNT162b2 (Part A)mRNA-1273 (Part A)BNT162b2 (Part B)mRNA-1273 (Part B)Total
Median77 (75 to 87)78 (75 to 85)79 (75 to 99)79 (75 to 99)79 (75 to 99)
Sex: Female, Male
Sex: Female, Male(Participants)BNT162b2 (Part A)mRNA-1273 (Part A)BNT162b2 (Part B)mRNA-1273 (Part B)Total
Female9116768155
Male16166867167
Race and Ethnicity Not Collected
Race and Ethnicity Not Collected(Participants)BNT162b2 (Part A)mRNA-1273 (Part A)BNT162b2 (Part B)mRNA-1273 (Part B)Total
Count of participants————0
Height
Height(cm)BNT162b2 (Part A)mRNA-1273 (Part A)BNT162b2 (Part B)mRNA-1273 (Part B)Total
Median171 (155 to 190)174 (149 to 198)169 (143 to 189)169 (145 to 198)169 (143 to 198)
Weight
Weight(kg)BNT162b2 (Part A)mRNA-1273 (Part A)BNT162b2 (Part B)mRNA-1273 (Part B)Total
Median75 (53 to 97)73 (51 to 100)72 (41 to 119)75 (41.7 to 110)74 (41 to 119)
BMI
BMI(kg/m2)BNT162b2 (Part A)mRNA-1273 (Part A)BNT162b2 (Part B)mRNA-1273 (Part B)Total
Median25.6 (20.3 to 32.8)24.1 (16.8 to 32.6)25.4 (16.6 to 40.2)25.4 (18 to 41.8)25.4 (16.6 to 41.8)
Duration between 1st and 2nd vaccination in days
Duration between 1st and 2nd vaccination in days(days)BNT162b2 (Part A)mRNA-1273 (Part A)BNT162b2 (Part B)mRNA-1273 (Part B)Total
Median42 (21 to 84)42 (21 to 111)22 (20 to 86)22 (16 to 114)22 (16 to 114)
Duration between 2nd and 3rd vaccination in days
Duration between 2nd and 3rd vaccination in days(days)BNT162b2 (Part A)mRNA-1273 (Part A)BNT162b2 (Part B)mRNA-1273 (Part B)Total
Median192 (185 to 255)190 (184 to 273)207 (124 to 303)205 (126 to 313)206.5 (124 to 313)
08

Study locations

9 sites
  • University Hospital Cologne
    Cologne, 50931, Germany
  • University Hospital Frankfurt
    Frankfurt, 60590, Germany
  • Hannover Medical School Hospital
    Hannover, 30625, Germany
  • Vilnius University Hospital Santaros Klinikos
    Vilnius, 08661, Lithuania
  • Helse Bergen HF, Haukeland University Hospital
    Bergen, 5021, Norway
  • Hospital Universitari Germans Trias i Pujol
    Badalona, 08916, Spain
  • Reina Sofia University Hospital
    Córdoba, 14004, Spain
  • La Paz University Hospital
    Madrid, 28046, Spain
  • Biodonostia Health Research Institute
    San Sebastián, 20014, Spain
09

References and documents

Publications

  • Neuhann JM, Stemler J, Carcas A, Frias-Iniesta J, Bethe U, Heringer S, Tischmann L, Zarrouk M, Cuppers A, Konig F, Posch M, Cornely OA. A multinational, phase 2, randomised, adaptive protocol to evaluate immunogenicity and reactogenicity of different COVID-19 vaccines in adults >/=75 already vaccinated against SARS-CoV-2 (EU-COVAT-1-AGED): a trial conducted within the VACCELERATE network. Trials. 2022 Oct 8;23(1):865. doi: 10.1186/s13063-022-06791-y. PubMed 36209129 ↗

Study documents

PDFs hosted by the registry, ClinicalTrials.gov.

Individual participant data

Plan to share: Yes — Making de-identified/anonymized data accessible is currently under way. We expect to grant access through a central independent data repository no later than January 2025. Any pertinent information will be updated in due course.

Supporting information: Study protocol, Statistical analysis plan, Informed consent form

Time frame: Making de-identified/anonymized data accessible is currently under way. We expect to grant access through a central independent data repository no later than January 2025. Any pertinent information will be updated in due course.

Access criteria: To be announced.

10

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on May 20, 2025, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
11

Registry details

Key details

Study ID
NCT05160766
Lead sponsor
Oliver Cornely, MD
Collaborators
VACCELERATE, European Commission
Responsible party
Oliver Cornely, MD (Principal Coordinating Investigator, University of Cologne) — Sponsor-investigator
First posted
Dec 16, 2021
Start date
Nov 8, 2021
Primary completion
Oct 1, 2022
Completion
Sep 13, 2023
Results posted
May 20, 2025
Last update
May 20, 2025

Study contacts

Oliver A Cornely, MD
principal investigator · University of Cologne

Oversight

Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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Studies of the drugs tested here: BNT162 Vaccine · 2019-nCoV Vaccine mRNA-1273

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