| Bias | Author's judgement | Support for judgement |
| Randomization |
Some concerns |
Comment: Allocation sequence generated randomly. No information on method used for allocation concelament. Quote: "As a safety measure, 6 participants were ini-tially randomly assigned in a 1:1 ratio to the 5-?g and 25-?g rSARS-CoV-2 plus Matrix-M1 groups (groups C and D), vaccinated in an open-label manner, and observed for reactogenicity for 48 hours. Thereafter, the remaining 125 participants were randomly assigned, in a 1:1:1:1:1 ratio and in a blinded manner to one of five vaccine groups according to pregenerated randomization sched-ules, without stratification". |
| Deviations from intervention |
Low |
Comment: Double blind study. 7 deviations from intended intervention (5,22%). 2 participants did not received the allocated intervention after physician decision and there were 5 early terminations to day 35, no reason reported. Trialists used ITT in the analyses. |
| Missing outcome data |
Low |
Comment: 134 randomized/131 analyzed. 3,73 % missing data, not likely to affect the results Risk assessed to be "low" for the outcomes: SARS-RBD-specific antibodies Seroconversion, SARS neutralising antibodies seroconversion, Adverse events and Serious adverse events. |
| Measurement of the outcome |
Low |
Comment: Double blinded study. Risk assessed to be "low" for the outcomes: SARS-RBD-specific antibodies Seroconversion, SARS neutralising antibodies seroconversion, Adverse events and Serious adverse events. |
| Selection of the reported results |
Low |
Comment: Protocol and statistical plan available, Outcomes reported as prespecified. Risk assessed to be "low" for the outcomes: SARS-RBD-specific antibodies Seroconversion, SARS neutralising antibodies seroconversion, Adverse events and Serious adverse events. |
| Overall risk of bias |
Some concerns |