Trial NCT04764422
Publication Pitisuttithum P, medRxiv, 2021
Primary outcome on the report: Frequency and intensity of solicited injection site and systemic AEs during 7 days after vaccination; frequency, intensity, and relatedness of clinically significant haematological and biochemical measurements at 7 days after each vaccination; frequency, intensity, and relatedness of unsolicited AEs during 28 days after each vaccination; and occurrence of medically-attended AEs, serious AEs, and AEs of special interest during the interim analysis period of 57 days after-first 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
Some concerns 		Quote: “Enrolled subjects were randomly assigned … using a computer-generated block randomisation sequence prepared by an independent statistician”
Comment: Allocation sequence random. No information on allocation concealment.
Deviations from intervention
Low 		Quote: "All participants and personnel other than the unmasked pharmacy team and vaccinators were masked to treatment"
Comment: Blinded study (participants and personnel/carers).
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 outcomes: Specific antibody GMTs and GMRs. Neutralizing antibody GMTs and GMRs. Local adverse events. Systemic adverse events. Adverse events. Serious adverse events.
Missing outcome data
Low 		Comment: 210 participants randomized; 210 participants analyzed for safety; 206 participants analyzed for immunogenicity.
Data available for all or nearly all participants randomized.
Risk assessed to be low for the outcomes: Specific antibody GMTs and GMRs. Neutralizing antibody GMTs and GMRs. Local adverse events. Systemic adverse events. Adverse events. 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.
Blinded study (outcome assessor).
Risk assessed to be low for the outcomes: Specific antibody GMTs and GMRs. Neutralizing antibody GMTs and GMRs. Local adverse events. Systemic adverse events. Adverse events. Serious adverse events.
Selection of the reported results
Low 		Comment: The prospective registry was available (dated 21 February 2021).
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: Specific antibody GMTs and GMRs. Neutralizing antibody GMTs and GMRs. Local adverse events. Systemic adverse events. Adverse events. Serious adverse events.
Overall risk of bias
Some concerns