Trial NCT04892459
Publication Li J, Nat. Med., 2022
Dates: 2021-05-25 to 2021-05-26
Funding: Public/non profit (National Natural Science Foundation of China)
Conflict of interest: Yes

Methods
RCT
Location : Single center / China
Follow-up duration (months): 1
CoronaVac (2 doses) + CoronaVac booster (n=100)
CoronaVac (2 doses) + Convidecia booster (n=100)
Inclusion criteria
  • Healthy participants
  • male or female
  • aged between 18 and 59 years
  • received two doses of CoronaVac in the past 3~6 months
Exclusion criteria
  • Previous clinical or virologic COVID-19 diagnosis or SARS-CoV-2 infection
  • women with positive urine pregnancy test
Interventions
Intervention
2 IM doses CoronaVac + 1 IM booster dose Convidecia 5×10^10 vp, 3-6 months later
Control
2 IM doses CoronaVac + 1 IM booster dose CoronaVac 600 SU, 3-6 months later
Participants
Randomized
200 participants
Characteristics of participants
Type of participants: Healthy adults
N=200
122 males
Children: 0
Pregnant women: 0
Mean age:
Age range: NR
Description of participants
Healthy adults with no previous clinical or virologic COVID-19 diagnosis or SARS-CoV-2 infection at one centre in China
Primary outcome
In the register
1) Incidence of adverse reactions within 28 days after the booster dose; 2) GMT of neutralizing antibodies against live SARS-CoV-2 virus on day 14 after the booster dose
In the report
1) adverse reactions within 28 days after the vaccination; 2) geometric mean titres of neutralizing antibodies against live SARS-CoV-2 virus at 14 days after the booster vaccination
Documents
available

Protocol

Yes. In English

Statistical plan

Yes

Data-sharing stated: Yes
Data accessibility: Corresponding authors: Dr. Chen at Beijing Institute of Biotechnology, cw0226@foxmail.com; Dr. Zhu at Jiangsu Provincial Center for Disease Control and Prevention, jszfc@vip.sina.com The results supporting the findings in this study are available upon request from the corresponding authors
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 supplementary materials and prospective study registry were used in data extraction and risk of bias assessment. Neither protocol nor statistical analysis plan were available at the time of data extraction. The target sample size specified in the registry was achieved. The article presented results on adults primed with one or two doses of CoronaVac that were randomly assigned to receive a booster dose of Convidecia or CoronaVac. Here we report on the two arms that were randomized to receive a booster dose after two doses CoronaVac. There were no important differences between registry and pre-print in population, procedures, interventions or outcomes. This trial was updated on Mars 9th, 2022 after the publication of the study report.