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 |
Some concerns |
Quote: "Eligible participants were randomly assigned to one of two
vaccines in a 1:1 ratio and.."
Comment: Allocation sequence probably random. No information on allocation concealment |
| Deviations from intervention |
Some concerns |
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 SERIOUS ADVERSE EVENTS ITT analysis was performed for this outcome. As we are assessing the effect of assignment to intervention, the analysis method performed on these safety outcomes, was considered appropriate. Risk assessed to be low for the outcomes: Serious adverse events. NEUTRALIZING ANTIBODY GMT, NEUTRALIZING ANTIBODY GMT OMICRON, NEUTRALIZING ANTIBODY SEROCONVERSION RATE OMICRON Per-protocol analysis was performed on the outcomes. Reasons for exclusion: no results available (no reasons provided). As we are assessing the effect of assignment to intervention (intention-to-treat effect), we considered that the data were analyzed inappropriately. There was probably no substantial impact of failure to analyze participants according to their randomized assignment due to small number of participants excluded from the analysis. Risk assessed to be some concerns for the outcomes: Neutralizing antibody GMT. Neutralizing antibody GMT Omicron. nAb Seroconversion rate Omicron |
| Missing outcome data |
Low |
Comment: 202 participants randomized; 202 participants analyzed for safety outcomes; 196 participants analyzed for immunogenicity outcomes.
Data available for all or nearly all participants randomized. Risk assessed to be low for the outcomes: Neutralizing antibody GMT. Neutralizing antibody GMT Omicron. nAb Seroconversion rate Omicron. Serious adverse events |
| Measurement of the outcome |
Low |
Comment: Method of measuring the outcome probably appropriate.
Measurement or ascertainment of outcome probably does not differ between groups. Unblinded study (outcome assessor) 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: Serious adverse events. NEUTRALIZING ANTIBODY GMT, NEUTRALIZING ANTIBODY GMT OMICRON. NEUTRALIZING ANTIBODY SEROCONVERSION RATE OMICRON Observer-reported outcome not involving judgement. Risk assessed to be low for the outcomes: Neutralizing antibody GMT. Neutralizing antibody GMT Omicron. nAb Seroconversion rate. Omicron |
| Selection of the reported results |
Low |
Comment: The registry was available (dated March 21, 2022)
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: Neutralizing antibody GMT. Neutralizing antibody GMT Omicron.nAb Seroconversion rate Omicron. Serious adverse events. |
| Overall risk of bias |
Some concerns |