Trial NCT04999111
Publication Amplify, Unpublished, 2023
Funding: Not reported/unclear
Conflict of interest: *
Methods | |
RCT | |
Location :
Multicenter / USA Follow-up duration (months): 4.5 | |
1x10^10 vp Ad26.COV2.S (n = 116) 2.5x10^10 vp Ad26.COV2.S (n = 330) 5x10^10 vp Ad26.COV2.S (n = 331) |
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Inclusion criteria |
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Exclusion criteria |
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Interventions | |
Intervention
1 IM dose of 1x10^10 vp Ad26.COV2.S (booster), at least 6 months after 1-dose prime vaccination with Ad26.COV2.S 1 IM dose of 2.5x10^10 vp Ad26.COV2.S (booster), at least 6 months after 1-dose prime vaccination with Ad26.COV2.S |
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Control
1 IM dose of 5x10^10 vp Ad26.COV2.S (booster), at least 6 months after 1-dose prime vaccination with Ad26.COV2.S | |
Participants | |
Randomized 777 participants | |
Characteristics of participants Type of participants: Adults including elderly and stable co-morbidities N=777 400 males Children: 0 Mean age: Age range: NR | |
Description of participants Adults including elderly and stable co-morbidities with no history of COVID-19 in 21 centres in USA. | |
Primary outcome | |
In the register 1. Percentage of Participants With Serological Response Against SARS-CoV-2 Original Strain 14 Days After Ad26.COV2.S Booster Vaccination After Completing Primary Vaccination With Ad26.COV2.S [ Time Frame: 14 days after Ad26.COV2.S booster vaccination (i.e., on Day 15) ]: Percentage of participants with serological response against SARS-CoV-2 original strain (Wuhan, 2019, whole genome sequence) 14 days after Ad26.COV2.S booster vaccination after completing primary vaccination with Ad26.COV2.S were reported. A participant was considered a responder if one or both of the following conditions were satisfied: (1) Pre-booster titer less than (<) lower limit of quantification (LLOQ) and post-booster titer greater than or equal to (>=) 4*LLOQ or (2) Pre-booster titer greater than (>) LLOQ and post-booster titer >=4*pre-booster titer value. 2. Geometric Mean Titers (GMTs) of Neutralizing Antibodies Against SARS-CoV-2 Original Strain 14 Days After Ad26.COV2.S Booster Vaccination After Completing Primary Vaccination With Ad26.COV2.S [ Time Frame: 14 days after Ad26.COV2.S booster vaccination (i.e., on Day 15) ]: GMTs of neutralizing antibodies against SARS-CoV-2 original strain 14 days after Ad26.COV2.S booster vaccination after completing primary vaccination with Ad26.COV2.S (5×10^10 vp dose level) were reported. GMT against original strain was assessed by virus neutralization assay (VNA). 3. Percentage of Participants With Serological Response Against SARS-CoV-2 Original Strain 28 Days After Primary Vaccination With Ad26.COV2.S [ Time Frame: 28 days after primary vaccination with Ad26.COV2.S (Day 29 of study VAC31518COV3001) ]: Percentage of participants with serological response against SARS-CoV-2 original strain 28 days after primary vaccination with Ad26.COV2.S (5×10^10 vp dose level) were reported. A participant was considered a responder if one or both of the following conditions were satisfied: (1) Pre-dose titer | |
In the report NR | |
Documents available |
Protocol Yes. In English Statistical plan Yes Data-sharing stated:
Yes |
Risk of bias Overall The overall risk of bias reported in the table corresponds to the highest risk of bias for the outcomes assessed for the systematic review |
Some concerns |
General comment | Unpublished results posted on the trial registry. In addition to the study registry, the protocol and statistical analysis plan were used in data extraction and risk of bias assessment. Preliminary analysis, follow-up visits were scheduled up to day 235 after booster; longest follow-up was for SAEs and results are reported up to data cut-off (15 December 2021), which was up to 4.5 months. The target sample size specified in the registry was achieved. Only the primary outcomes in the registry were available, and these were reported; some outcomes were not reported. There is no change from the trial registration in the intervention and control treatments. |