Trial NCT04456595
Publication Palacios R, SSRN, 2021
Dates: 2020-07-21 to 2020-12-16
Funding: Public/non profit (Fundação Butantan, Instituto Butantan, and São Paulo Research Foundation (FAPESP))
Conflict of interest: Yes

Methods
RCT
Location : Multicenter / Brazil
Follow-up duration (months): 12
CoronaVac (n=6201)
Placebo (n=6207)
Inclusion criteria
  • 18 years of age or older
  • work as healthcare professional caring for COVID-19 patients
  • sign the informed consent form
Exclusion criteria
  • Pregnant or lactating women
  • unstable chronic disease
  • previous use of any COVID-19 vaccines
  • acute disease symptoms including COVID-19 in the previous 72 hours
Interventions
Intervention
2 IM doses of 3mcg CoronaVac, 14 days apart
Control
2 IM doses of adjuvant, 14 days apart
Participants
Randomized
12408 participants
Characteristics of participants
Type of participants: Healthcare workers
N=12408
4441 males
Children: 0
Pregnant women: 0
Immunocompromized patients: 0
Mean age:
Age range: NR
Description of participants
Healthcare professionals with or without previous COVID-19 infection caring for COVID-19 patients at 16 centers in Brazil.
Primary outcome
In the register
Incidence of COVID-19 cases after two-doses immunization schedule [ Time Frame: Two weeks after second dose up to one year after first dose ]; Frequency of adverse events up to seven days after immunization [ Time Frame: Seven days after each immunization ]
In the report
The primary endpoint was the efficacy of CoronaVac against confirmed symptomatic COVID-19 with onset at least 14 days after the second injection in the per protocol population. The primary safety endpoint was incidence of adverse reactions within 7 days after injection.
Documents
available

Protocol

Yes. In English

Statistical plan

Yes

Data-sharing stated: Yes, When the study is completed and the analyzes described in the protocol and the study data analysis plan are carried out.
Data accessibility: The Sponsor: Instituto Butantan. Ricardo Palacios, MD, PhD Medical Director of Clinical Research Instituto Butantan Av. Vital Brasil, 1500 São Paulo, SP, Brazil CEP 05503-900 Phone: (11) 37232121 E-mail: ricardo.palacios@butantan.gov.br
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 article, the study registry, protocol, and statistical analysis plan were used in data extraction and risk of bias assessment. The target sample size specified in the registry (n=12,688) was nearly achieved (n=12,408 randomized). This is a report of a phase 3 trial where recruitment was completed and follow-up is ongoing (up to 1 year follow-up is planned). 79% (n=9823) of participants were analyzed for efficacy so far. Planned outcome SARS-CoV-2 infection confirmed by virology or serology was not reported. Other outcomes were reported as planned. There is no change from the trial registration in the intervention and control interventions.