Trial EudraCT021-002927-39
Publication Reindl-Schwaighofer R, JAMA, 2021

Funding: Public/non profit (Medical University of Vienna; Austrian Agency for Health and Food Safety; Medical-Scientific Fund of the Mayor of the Federal Capital of Vienna; Christine Vranitzky-Stiftung Foundation; Medical University of Vienna Transplantation Research Platform )
Conflict of interest: Yes

Methods
RCT
Location : Single center / Austria
Follow-up duration (months): 1.4
2 doses mRNA-1273 or BNT162b2 with homologous booster (n = 101)
2 doses mRNA-1273 or BNT162b2 with Ad26COVS1 heterologous booster (n = 100)
Inclusion criteria
  • Received a kidney transplantation
  • full SARS-CoV-2 vaccination with mRNA vaccine (two doses) at least 4 weeks before screening
  • > 18 years of age
  • no SARS-CoV-2 spike protein antibodies at least 4 weeks after the second dose of an mRNA vaccine
Exclusion criteria
  • Acute illness with fever
  • Prior documented infection with SARS-CoV-2
  • triple anticoagulation therapy
  • currently enrolled in or has not yet completed at least 30 days since ending other investigational device or drug trial(s), or subject is receiving other investigational agent(s)
  • known sensitivity or intolerance to any of the products to be administered for the purpose of this study
  • any kind of disorder that compromises the ability of the subject to give written informed consent and/or to comply with the study procedures
  • pregnant or breast feeding
Interventions
Intervention
1 IM mRNA booster dose (BNT162b2 30 mcg or mRNA-1273 100 mcg), 8-13 weeks after 2-dose primary schedule of mRNA-based vaccine (BNT162b2 or mRNA-1273)
Control
1 IM 5 × 10^10 vp booster dose of Ad26COV2.S, 8-13 weeks after 2-dose primary schedule of mRNA-based vaccine (BNT162b2 or mRNA-1273)
Participants
Randomized
201 participants
Characteristics of participants
Type of participants: Kidney transplant recipients
N=201
115 males
Children: 0
Pregnant women: 0
Immunocompromized patients: 197
Mean age:
Age range: NR
Description of participants
Adult kidney transplant recipients with no history of COVID-19 infection and without an antibody response 4 weeks after a 2-dose mRNA vaccine schedule at a single center in Austria.
Primary outcome
In the register
Number of patients presenting a positive humoral immune response (antibody) at 4 weeks after vaccination
In the report
seroconversion rate (ie, detectable SARS-CoV-2 spike protein antibodies at a level >0.8 units [U]/mL) 4 weeks (29-42 days) following the third dose.
Documents
available

Protocol

Yes. In English

Statistical plan

Yes

Data-sharing stated: Yes, With publication
Data accessibility: roman.reindl-schwaighofer@meduniwien.ac.at

Risk of bias
Overall
The overall risk of bias reported in the table corresponds to the highest risk of bias for the outcomes assessed for the systematic review
Some concerns
General comment In addition to the published article, the registry, protocol, statistical analysis plan and supplementary appendices were used in data extraction and assessment of risk of bias. There were no important differences between protocol/registry and published report in population, procedures, or interventions. The study (n = 201) achieved its target sample size (n = 200).