Trial NCT04907331; 2021-002171-19
Publication Bánki Z, EBioMedicine, 2022
Dates: 2021-05-11 to 2021-07-10
Funding: Public/non profit (Medical University of Innsbruck; National Institute of Health; SARS-CoV-2 Assessment of Viral Evolution (SAVE) program; NIAID Collaborative Influenza Vaccine Innovation Centers (CIVIC))
Conflict of interest: Yes

Methods
RCT
Location : Multicenter / Austria
Follow-up duration (months): 1
ChAdOx1/BNT162b2 (n=118)
ChAdOx1/ChAdOx1 (n=116)
Inclusion criteria
  • Healthy volunteers
  • between 18 and 65 years
  • previously received one vaccination with AZ or BNT.
Exclusion criteria
  • Previous positive PCR-test result for SARS-CoV-2 or positive anti-SARS-CoV-2 nucleoprotein (N) antibody test
  • history of leukemia, lymphoma, or underlying bone marrow disorder (e.g., myelodysplasia, myeloma, myeloproliferative disorder) or bone marrow transplant
  • malignancy that required treatment with chemotherapy, immunotherapy, radiation therapy, or other antineoplastic target therapies within 24 months prior to study enrollment
  • Female participants of childbearing potential were only enrolled in the study if the participant had a negative urine pregnancy test at screening, agreed to practice adequate contraception from providing consent until 3 months after administration of study vaccine and were not currently breastfeeding.
Interventions
Intervention
1 IM dose of 30mcg
Control
1 IM dose of 5x10^10 VPs
Participants
Randomized
234 participants
Characteristics of participants
Type of participants: Healthy adults
N=234
103 males
Children: 0
Pregnant women: 0
Immunocompromized patients: 0
Mean age:
Age range: NR
Description of participants
Healthy adults with no history of COVID-19 in 3 centres in Austria.
Primary outcome
In the register
1.Neutralizing antibodies [ Time Frame: 10 to 180 days ] in the heterologous arm the levels of neutralizing antibodies are at least as high as in the homologous arms 2.T cells [ Time Frame: 10-180 days ] The level of T cell responses to SARS-CoV-2 S protein epitopes is at leas as high in the heterologous are than in the homologous arms 3.vaccine failures [ Time Frame: 180 days post intervention ] Vaccine failures are not more frequent in the heterologous arm than in the homologous arms.
In the report
Levels of neutralizing antibodies against wild type and immune escape variants.
Documents
available

Protocol

Yes. In English

Statistical plan

Yes

Data-sharing stated: Yes, Upon publication
Data accessibility: F. Krammer: florian.krammer@mssm.edu, D. von Laer: dorothee.von-laer@i-med.ac.at, D. Weiskopf:daniela@lji.org, J Kimpel:janine.kimpel@i-med.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 study registry, appendices and protocol were used in data extraction and risk of bias assessment. The article presented preliminary analyses for a study with ongoing follow-up. The AZ/AZ study arm was terminated after this analysis early as recommended by the Safety Monitoring Board.