Trial NCT04530357
Publication Zakarya K , EClinicalMedicine, 2021
Primary outcome on the report: 1) solicited adverse reactions within 7 days after each dose; 2) unsolicited adverse events (AEs) for 21 days after each vaccination; 3) geometric mean titres (GMTs) of S-specific antibodies measured on days 21 and 42 after vaccination; 4) GMTs of virus neutralizing antibodies measured on days 21 and 42 after vaccination

Note: The risk of bias by domain corresponds to the highest risk of bias among outcomes by domain.
The overall risk of bias corresponds to the overall highest risk of bias assessed among outcomes.

Bias Author's judgement Support for judgement
Randomization
Low 		Quote: "Eligible participants were sequentially assigned a study number at enrolment and were vaccinated according to the randomisation list prepared by an independent statistician. Study medications were allocated to codes by block randomisation using a computerised randomisation scheme generator"
Comment: Allocation sequence random. Allocation sequence concealed.
Deviations from intervention
Low 		Quote: “open-label"
Comment: Unblinded study (participants and personnel/carers)
Deviations from intended intervention arising because of the study context:
No participant cross-over.
Hence, deviations did not arise because of the trial context.
Data for the outcome were analyzed using intention-to-treat analysis. This method was considered appropriate to estimate the effect of assignment to intervention.
Risk assessed to be low for the outcome: Serious adverse events.
Missing outcome data
Low 		Comment: 200 participants randomized; 200 participants analyzed.
Data available for all participants randomized.
Risk assessed to be low for the outcome: Serious adverse events.
Measurement of the outcome
Some concerns 		Comment: Method of measuring the outcome probably appropriate.
Measurement or ascertainment of outcome probably does not differ between groups.
Unblinded study (outcome assessor)
The authors reported on adverse events that may contain both clinically- and laboratory-detected events, which can be influenced by knowledge of the intervention assignment, but is not likely in the context of the pandemic.
Risk assessed to be some concerns for the outcome: Serious adverse events.
Selection of the reported results
Low 		Comment: The prospective trial registry was available (dated 28 August 2020).
Outcome pre-specified.
Results were not selected from multiple outcome measurements or analyses of the data.
Trial analyzed as pre-specified.
Risk assessed to be low for the outcome: Serious adverse events.
Overall risk of bias
Some concerns