Trial NCT04324606;ISRCTN89951424;NCT04400838;NCT04444674
Publication Voysey M, Lancet, 2021
Dates: 2020-04-23 to 2020-12-06
Funding: Mixed (UKRI, NIHR, CEPI, the Bill & Melinda Gates Foundation, the Lemann Foundation, Rede D’OR, the Brava and Telles Foundation, NIHR Oxford Biomedical Research Centre, Thames Valley and South Midland's NIHR Clinical Research Network, and Astra Zeneca)
Conflict of interest: Yes
Methods | |
RCT | |
Location :
Multicenter / Brazil, South Africa, UK Follow-up duration (months): 3.94 | |
•ChAdOx1 (n=12408)
•Control (n = 12014) |
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Inclusion criteria |
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Exclusion criteria |
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Interventions | |
Intervention
2 IM doses of 2.2 or 5.5x10^10 vp ChAdOx1 nCoV-19 vaccine on Days 0/28 (planned interval) |
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Control
2 IM doses of MenACWY control vaccine or normal saline Days 0/28 (planned interval) | |
Participants | |
Randomized 24422 participants | |
Characteristics of participants Type of participants: Adults N=24422 7492 males Children: 0 Pregnant women: 0 Immunocompromized patients: 104 Mean age: Age range: NR | |
Description of participants Adults seronegative at baseline from four studies in multiple centres in Brazil, South Africa, and the UK | |
Primary outcome | |
In the register The primary outcome was virologically confirmed symptomatic COVID-19 disease, defined as a nucleic acid amplification test (NAAT)-positive swab combined with at least one qualifying symptom (fever ?37·8°C, cough, shortness of breath, anosmia, or ageusia). | |
In the report Symptomatic COVID-19 disease defined as a NAAT+ swab combined with at least one qualifying symptom (fever ? 37.8oC; cough; shortness of breath; anosmia or ageusia) | |
Documents available |
Protocol Yes. In English Statistical plan Yes Data-sharing stated:
Yes, when the trials are complete |
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 | In addition to the pre-print and published article, the trial registry, study protocol and statistical analysis plan were used in data extraction and assessment of risk of bias. Interim analyses combining data from four trials (COV001/2 (UK), COV003 (Brazil, COV005 (South Africa)) were presented updated with additional cases from an extra month of follow up (not a pre-planned analysis). Three studies were single blind and one (COV005) was double blind, all of the which are ongoing. The statistical analysis plan was developed once the trials were underway but before data cutoff on Dec 7, 2020. There were several changes to the protocols after study initiation, notably: 1) a booster dose incorporated into the three trials that were initially designed to assess a single-dose of ChAdOx1 nCoV-19 compared with control (COV001, COV002, and COV003) after review of the antibody response data from COV001. 2) In COV002 a dose of 5 × 10¹? viral particles was chosen but a 2·2 × 10¹? viral particles dose was given for some of the participants future batches are all released with a specification dose of 3·5–6·5 × 10¹? viral particles, and this was used for the booster doses in the efficacy and the protocol was amended resulting in enrolment of two distinct groups with different dosing regimens. Future batches are all released with a specification dose of 3·5–6·5 × 10¹? viral particles, and this was used for the booster doses in the efficacy analysis presented here. Otherwise, there were no major differences in population, procedures or treatment between the published article and registry and protocol. Primary analysis presents an update with additional cases from an extra month of follow up in relation to the previous publication. This trial was updated on February 24th, 2021 after publication of the study report. |