| Bias | Author's judgement | Support for judgement |
| Randomization |
Some concerns |
Quote: Healthy seronegative subjects 18-55 years of age who met all inclusion criteria and no exclusion criterion were enrolled and randomized into nine groups. Comment: No information on allocation sequence generation. No information on allocation concealment. |
| Deviations from intervention |
Low |
Quote: "The participants and the personnel collecting the safety information and testing laboratories remained blinded to treatment allocation." Comment: Blinded study (patients, personnel, and investigators). No participant cross-over. Data were analyzed using intention-to-treat analysis. Risk assessed to be low for the outcomes: Adverse events. Withdrawal due to adverse events. Serious adverse events. |
| Missing outcome data |
Low |
Comment: Data from interim analysis. 180 patients randomized; 180 patients analyzed Data available for all or nearly all participants. Risk assessed to be low for the outcomes: Adverse events. Withdrawal due to adverse events. Serious adverse events. |
| Measurement of the outcome |
Low |
Comment: Blinded study (outcome assessor). Risk assessed to be low for the outcomes: Adverse events. Withdrawal due to adverse events. Serious adverse events. |
| Selection of the reported results |
Low |
Comment: The trial registry is available. The protocol and statistical analysis plan were mentioned in the pre-print, but were not available at the time of assessment. Adverse events and serious adverse events were listed as outcomes, with timepoints specified in the registry. 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 outcomes: Adverse events. Withdrawal due to adverse events. Serious adverse events. |
| Overall risk of bias |
Some concerns |