Trial NCT04444674, PACTR202006922165132
Publication Madhi S, Lancet HIV, 2021
Primary outcome on the report: Local and systemic reactogenicity and adverse events for 7 and 28 days following vaccination; cellular and humoral immunogenicity of ChAdOx1 nCoV-19, as assessed by quantification of serum antibody (IgG) to SARS-CoV-2 full-length spike (FLS) protein, receptor-binding domain (RBD), and virus neutralizing antibody (NAb) assays against live and/or pseudotyped SARS-CoV-2 virus for 7 days after receipt of vaccine

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 lists were prepared by the study statistician (MV) using block randomisation, stratified by study site and study group, and uploaded into to the secure web platform used for the study electronic case report form (REDCap version 9.5.22) ... the randomisation list was held by the unmasked study pharmacist who prepared the vaccines for administration, with all other trial staff masked to group allocation"
Comment: Allocation sequence random. Allocation sequence concealed.
Risk assessed as low.
Deviations from intervention
Low 		Quote: "the randomisation list was held by the unmasked study pharmacist who prepared the vaccines for administration, with all other trial staff masked to group allocation. The trial staff administering the vaccine prepared vaccines out of sight of the participants and syringes were covered with an opaque material until ready for administration to ensure masking of participants"
Comment: Blinded study (participants, personnel).
All randomized participants who received at least one dose were analyzed for efficacy and safety outcomes.
As we are assessing the effect of assignment to intervention, the analysis method performed on these outcomes, was considered appropriate.
Risk assessed to be low for outcomes: Confirmed symptomatic COVID. Confirmed severe COVID. Mortality. Serious adverse events.
Missing outcome data
Low 		Comment: 104 participants randomized; 103 participants analyzed for efficacy; 102-104 participants analyzed for safety
Data available for all or nearly all participants randomized.
Risk assessed to be low for the outcomes: Confirmed symptomatic COVID. Confirmed severe COVID. Mortality. 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: Confirmed symptomatic COVID. Confirmed severe COVID. Mortality. Serious adverse events.
Selection of the reported results
Low 		Comment: Prospective registry (June 23, 2020) was available.
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: Confirmed symptomatic COVID. Confirmed severe COVID. Mortality. Serious adverse events.
Overall risk of bias
Low