Booster Dose of COVID-19 Vaccine for Kidney Transplant Recipients Without Adequate Humoral Response (WHO)
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ClinicalTrials.gov Identifier: NCT04961229 |
Recruitment Status :
Not yet recruiting
First Posted : July 14, 2021
Last Update Posted : October 8, 2021
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Introduction: Inadequate antibody response to mRNA SARS-CoV-2 vaccination has been described among kidney transplant recipients. Immunosuppression level and specifically, use of antimetabolite in the maintenance immunosuppressive regimen, are associated with inadequate response. In light of the severe consequences of COVID-19 in solid organ transplant recipients, we believe it is justified to examine new vaccination strategies in these patients.
Methods and analysis: BECAME is a single center, open label, investigator-initiated randomised controlled, superiority trial, aiming to compare immunosuppression reduction combined with a third BNT162b2 vaccine dose versus third dose alone. The primary outcome will be seropositivity rate against SARS-CoV-2. A sample size of 154 patients was calculated for the seropositivity endpoint assuming 25% seropositivity in the control group and 50% in the intervention group. A sample of participant per arm will be also teste for T-cell response. We also plan to perform a prospective observational study, evaluating seropositivity among ~350 kidney transplant recipients consenting to receive a third vaccine dose, who are not eligible for the randomised controlled trial.
Ethics and dissemination: The trial is approved by local ethics committee of Rabin medical center (RMC-0192- 21). Results of this trial will be published; trial data will be available. Protocol amendments will be submitted to the local ethics committee.
Condition or disease | Intervention/treatment | Phase |
---|---|---|
COVID-19 Acute Respiratory Distress Syndrome Immunosuppression | Biological: The Pfizer mRNA-based BNT162b2 vaccine | Phase 4 |
All recipients more than 6 months post transplantation and at least 3 weeks following second vaccine dose will be approached and invited to a first study visit.
At first visit:
- Signed informed consent will be obtained from participants willing to participate by study investigators who usually work in the transplantation clinic.
- Anti-spike antibody response will be assessed using SARS-CoV-2 IgG II Quant (Abbott©) assay. Participants who have a documented seronegative test in the last 6 weeks will not be tested again.
Participants will be invited for an additional visit once negative serology will be reported, within 7 days of serology collection. At this second visit all participants who gave informed consent to participate in either the prospective non-randomised study or RCT will receive a single vaccine dose.
In addition, participants in the RCT will be randomised into two groups:
- Third booster dose of BNT162b2 (one standard dose) with no change in immunosuppression protocol
- Third booster dose of BNT162b2 (one standard dose) with immunosuppression reduction according to protocol (mycophenolic temporary cessation 4 days before (5 half-lives) and one week (expected antibody response) after vaccination (to allow for antibody response).
Patients who will test seronegative will be informed by the study coordinator by phone in which study arm they will be participating and receive instructions for immunosuppression reduction both during the phone call and by written instructions provided to each patient during the first visit (see Appendix). Participants in the observational study will receive a third vaccine standard dose, without any change in immunosuppression (beyond routine care)
For all groups:
- Antibodies titer against spike protein will be evaluated again 2 weeks and 3, 6, 12 months after the third vaccine dose
- T-cell response will be evaluated for a subset of patients in each group (estimated 20 patients per arm) before booster dose, at 2 weeks after booster dose, and at 3 months. For T cell response quantification peripheral blood mononuclear cell (PBMC) will be stimulated for 24 hours with spike protein and secreted interferon-gamma (IFNg) will be measured by ELISA.
- Follow-up for adverse events, rejection and SARS-CoV-2 infection will be performed at 2 weeks and at three, 6 and 12 months post third vaccination dose
Study Type : | Interventional (Clinical Trial) |
Estimated Enrollment : | 504 participants |
Allocation: | Randomized |
Intervention Model: | Parallel Assignment |
Masking: | None (Open Label) |
Primary Purpose: | Prevention |
Official Title: | Booster Dose of mRNA SARS-CoV-2 Vaccine for Kidney Transplant Recipients Without Adequate Humoral Response With or Without Immunosuppression Reduction - Protocol for a Randomised Controlled Trial (BECAME Study) |
Estimated Study Start Date : | October 2021 |
Estimated Primary Completion Date : | February 2022 |
Estimated Study Completion Date : | July 2022 |

Arm | Intervention/treatment |
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Experimental: Third dose of BNT162b2 vaccine with Immunosuppression reduction
Third dose of BNT162b2 vaccine with reduction of mycophenolic acid dose
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Biological: The Pfizer mRNA-based BNT162b2 vaccine
participants who gave informed consent to participate in either the prospective non-randomised study or RCT will receive a single vaccine dose. In addition, participants in the RCT will be randomised into two groups:
|
Experimental: Third dose of BNT162b2 vaccine without immunosuppression reduction
Third dose of BNT162b2 vaccine without reduction of mycophenolic acid dose
|
Biological: The Pfizer mRNA-based BNT162b2 vaccine
participants who gave informed consent to participate in either the prospective non-randomised study or RCT will receive a single vaccine dose. In addition, participants in the RCT will be randomised into two groups:
|
Experimental: Third dose of BNT162b2 vaccine
Third dose of BNT162b2 vaccine with no change in immunosuppression for patients that are excluded from the randomised trial
|
Biological: The Pfizer mRNA-based BNT162b2 vaccine
participants who gave informed consent to participate in either the prospective non-randomised study or RCT will receive a single vaccine dose. In addition, participants in the RCT will be randomised into two groups:
|
- anti-spike protein titer above 50 AU/ml 2 weeks post vaccination [ Time Frame: 2 weeks post vaccination ]positive humoral response against SARS-CoV-2
- anti-spike protein titer above 50 AU/ml 3-, 6-, and 12-months post vaccination [ Time Frame: 3-, 6-, and 12-months post vaccination ]positive humoral response against SARS-CoV-2
- Log transformed titer of anti-spike protein weeks and 3, 6, and 12 months post vaccination [ Time Frame: 2 weeks and 3, 6, and 12 months post vaccination ]Log transformed titer of anti-spike protein
- Adverse events to booster dose using CTCAE v4.0 criteria [ Time Frame: 2 weeks post vaccine ]Severity of adverse events will be assessed using CTCAE v4.0 criteria
- Acute rejection of the allograft either documented by biopsy or clinically suspected, defined as increase in creatinine by 20% from baseline, without any other plausible explanation [ Time Frame: 2 weeks, 3,6, and 12 months post vaccination ]either documented by biopsy or clinically suspected, defined as increase in creatinine by 20% from baseline, without any other plausible explanation
- positive PCR test to SARS-CoV-2 during the follow up period [ Time Frame: until 12 months following vaccine ]positive PCR test to SARS-CoV-2 during the follow up period
- Positive PCR tests to VZV, CMV [ Time Frame: during the follow up period ]Other viral reactivation during the follow up period: VZV, CMV, tested according to clinical suspicion
- Number of hospitalizations (numerical count) [ Time Frame: until 12 months following vaccine ]Number of hospitalizations

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Ages Eligible for Study: | 18 Years and older (Adult, Older Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | No |
Inclusion Criteria:
- kidney transplant recipients that received two doses of BNT162b2 vaccine at least 3 weeks prior to enrollment, and were seronegative (IgG against the spike protein of SARS-CoV-2 below 50 AU/ml) at least two weeks after the second vaccine dose
Additional inclusion criteria for the RCT:
- Recipients treated by three anti-rejection medications including: prednisone, tacrolimus, mycophenolate mofetil or mycophenolic acid.
- Tacrolimus trough blood levels 5-10 nGr/ml (lower or higher doses will have to be adjusted before re-considering for inclusion)
Exclusion Criteria:
- Past infection with SARS-CoV-2
- Pregnancy
- Age below 18 years
- Active infection
Additional exclusion criteria for RCT only:
- Recipients at a high risk for acute or chronic humoral rejection including:
- Recipients with positive panel-reactive antibody (PRA) (any positive value) at any time before or after transplantation
- Recipients that had an acute rejection in the last year
- Recipients less than 6 months after transplantation
- Recipients that are considered at high risk for rejection according to the primary care nephrologist
- Recipients taking less than 3 anti-rejection medications
- Recipients currently treated with mTOR inhibitors (everolimus, sirolimus) and/or azathioprine
- Recipients treated with plasmapheresis in the previous 3 months
- Recipients treated with eculizumab in the last year
- Recipient treated with IVIG in the previous 3 months
- Recipient treated with rituximab in the previous 6 months

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT04961229
Contact: Ruth Rahaminov | 97239376475 | rutir@clalit.org.il |
Principal Investigator: | Ruth Rahaminov | Rabin Medical Center, Beilinson Campus, Petah-Tikva, Israel |
Responsible Party: | dafna yahav, Clinical Professor, Infectious Diseases Unit, Rabin Medical Center, Beilinson Campus, Petah-Tikva, Israel, Rabin Medical Center |
ClinicalTrials.gov Identifier: | NCT04961229 |
Other Study ID Numbers: |
0192-21-RMC |
First Posted: | July 14, 2021 Key Record Dates |
Last Update Posted: | October 8, 2021 |
Last Verified: | October 2021 |
Individual Participant Data (IPD) Sharing Statement: | |
Plan to Share IPD: | Yes |
Plan Description: | According to request |
Supporting Materials: |
Study Protocol Informed Consent Form (ICF) |
Time Frame: | The data will become available once entered for all patients and analyzed, presumably at 1-January-2022. It will be available for one year. |
Access Criteria: | Researchers who would like to share the data will be requested to send the PI their protocol/reason for asking the data. After reviewing the request, if the protocol seems adequate in terms of clinical question and methodological quality, we will share anonymized data. |
Studies a U.S. FDA-regulated Drug Product: | Yes |
Studies a U.S. FDA-regulated Device Product: | No |
kidney transplant recipients COVID-19 vaccine immunosuppression reduction randomized controlled trial |
COVID-19 Respiratory Distress Syndrome Respiratory Distress Syndrome, Newborn Acute Lung Injury Respiratory Tract Infections Infections Pneumonia, Viral Pneumonia Virus Diseases Coronavirus Infections |
Coronaviridae Infections Nidovirales Infections RNA Virus Infections Lung Diseases Respiratory Tract Diseases Respiration Disorders Infant, Premature, Diseases Infant, Newborn, Diseases Lung Injury |