Trial NCT04582344
Publication Tanriover M, Lancet , 2021
Dates: 2020-09-15 to 2021-01-06
Funding: Public/non profit (Turkish Health Institutes Association (TUSEB))
Conflict of interest:
Methods | |
RCT | |
Location :
Multicenter / Turkey Follow-up duration (months): 6 | |
3 mcg CoronaVac (n=6650) Placebo (n=3568) |
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Inclusion criteria |
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Exclusion criteria |
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Interventions | |
Intervention
2 IM doses of 3mcg, 14 days apart |
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Control
2 IM doses of 0.45 mg/mL aluminium, 14 days apart | |
Participants | |
Randomized 10218 participants | |
Characteristics of participants Type of participants: Adults, Healthcare workers N=10218 5907 males Children: 0 Pregnant women: 0 Immunocompromized patients: 0 Mean age: Age range: NR | |
Description of participants Healthy healthcare workers and adults aged 18–59 years with no history of COVID-19 from 24 centres in Turkey | |
Primary outcome | |
In the register Protection Indexes of Two Vaccine Doses For Symptomatic COVID-19 [ Time Frame: 2 weeks afterthe second dose of vaccination ] | |
In the report Symptomatic COVID-19 cases confirmed by RT-PCR at least 14 days after the second dose of vaccination, assessed in the per protocol population | |
Documents available |
Protocol Yes. In English Statistical plan * Data-sharing stated:
Yes, upon completion of the clinical trial and publication of the completed study results |
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 supplementary materials, study registry and protocol were used in data extraction and risk of bias assessment. An interim analysis (data lock date: March 16, 2021) was presented and the study was terminated due an emergency use authorization for CoronaVac on Jan 13, 2021. As a result, the estimated enrollment specified in the registry was not achieved (n=13000), some outcomes were not reported in the paper, and some outcomes were reported at an earlier follow-up point than pre-specified in the registry. Participants were recruited in two consecutive cohorts of healthcare workers and general population. There is no change from the trial registration in the intervention and control arms. Quote: "During the study, the Ministry of Health gave an emergency use authorisation for CoronaVac on Jan 13, 2021, and started an immediate vaccination programme initially for health-care workers and later for the public, prioritising older adults (aged ≥65 years). Although recruitment of volunteers was ongoing at this time, to comply with the principles of the Declaration of Helsinki regarding using a placebo for human subjects in medical research, the ethics committee suggested discontinuing the masking and injection of participants in the placebo group. Consequently, the placebo recipients were offered vaccines, first in K1 and later in K2." |