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: "Randomisation was performed in the Research Electronic Data Entry (REDCap) system separately for the two cohorts stratified by study center, age group, sex, and presence of comorbidities."
Comment: Allocation sequence random Allocation sequence concealed Imbalances in baseline characteristics appear to be compatible with chance |
Deviations from intervention |
Low |
Quote: “Open label. Participants, treating physicians, and outcome assessors for clinical outcomes were not blinded.”
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 safety outcomes and allcause mortality were analyzed in those who received at least one dose of the intervention. This method was considered appropriate to estimate the effect of assignment to intervention. br/>Risk assessed to be low for the outcomes: Mortality. Local adverse events. Systemic adverse events. Serious adverse events. |
Missing outcome data |
Low |
Comment: 430 participants randomized; 407 analyzed for local and systemic adverse reactions; 415 participants analyzed for severe adverse events.
Data available for all or nearly all participants randomized serious adverse events and allcause mortality. Risk assessed to be low for the outcomes: Mortality. Serious adverse events. Data not available for all or nearly all participants randomized for local and systemic adverse reactions No evidence that the result is not biased. Reasons: Missingness could not depend on the true value of the outcome, this was assessed in ROB2. Risk assessed to be low for the outcomes: Local adverse events. Systemic adverse events. |
Measurement of the outcome |
Some concerns |
Quote: "Outcome assessors for clinical outcomes were not blinded"
Comment: Method of measuring the outcome probably appropriate.
Measurement or ascertainment of outcome probably does not differ between groups. Unblinded study (outcome assessor) MORTALITY Observer-reported outcome not involving judgement. Risk assessed to be low for the outcomes: Mortality. LOCAL, SYSTEMIC, SERIOUS ADVERSE EVENTS 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 outcomes: Local adverse events. Systemic adverse events. Serious adverse events. |
Selection of the reported results |
Low |
Comment: The protocol, statistical analysis plan, prospective registry were available
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: Local adverse events. Systemic adverse events. Serious adverse events. |
Overall risk of bias |
Some concerns |