Trial NCT04400838
Publication Voysey M, Lancet, 2020
Dates: 28/05/2020 to 04/11/2020
Funding: Mixed (United Kingdom National Institute for Health Research (NIHR), Coalition for Epidemic Preparedness Innovations, NIHR Oxford Biomedical Research Centre, Thames Valley and South Midlands NIHR Clinical Research Network, and AstraZeneca)
Conflict of interest: Yes
Methods | |
RCT | |
Location :
Multicenter / United Kingdom Follow-up duration (months): 2.95 | |
* | |
Inclusion criteria |
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Exclusion criteria |
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Interventions | |
Intervention
1 IM low-dose (2.2 × 10^10 vp)D0, 1 IM standard-dose (3.5-6.5 x 10^10 vp) ChAdOx1 nCoV-19 vaccine D28 2 IM standard-doses (3.5-6.5 x 10^10 vp) ChAdOx1 nCoV-19 vaccine on Days 0/28 |
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Control
2 IM doses of MenACWY control vaccine on Days 0/28 2 IM doses of MenACWY control vaccine on Days 0/28 | |
Participants | |
Randomized * participants | |
Characteristics of participants Type of participants: Healthy volunteers N=* 2920 males Children: 0 Pregnant women: 0 Immunocompromized patients: 0 Mean age: NR Age range: 18-55 | |
Description of participants Healthy adults in 18 centres in the UK | |
Primary outcome | |
In the register Number of virologically confirmed (PCR or NAAT positive) symptomatic cases of COVID-19; Occurrence of serious adverse events (SAEs) throughout the study duration | |
In the report Virologically confirmed, symptomatic COVID-19, defined as a NAAT-positive swab combined with at least one qualifying symptom (fever ?37·8°C, cough, shortness of breath, or 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 published article, the trial registry, study protocol and statistical analysis plan were used in data extraction and assessment of risk of bias. Interim efficacy was assessed by combining data from COV002 (UK) and COV003 (Brazil). The safety of the vaccine was assessed using data from four studies (COV001, COV002, COV003 and COV005). 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 Nov 4, 2020. COV001 and COV005 were not included in the efficacy assessment for the interim analysis due to having fewer than 5 cases eligible for inclusion in the primary outcome, however, according to the report COV001 included an efficacy cohort and COV005 expanded enrollment to a wider population with higher likelihood of exposure. This data (though small) was not reported, but "it is expected that they will be included in efficacy assessments in future analyses once more cases have accrued."
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. |