Trial NCT04611243
Publication Mok C K P, Am. J. Respir. Crit., 2022
Dates: 2021-08-18 to 2021-10-26
Funding: Public/non profit (the Health and Medical Research Fund Commissioned Research on the Novel Coronavirus Disease, Guangdong Province International Scientific and Technological Cooperation Projects, the National Research Foundation of Korea, US National Institutes of Health, National Natural Science Foundation of China (NSFC)/Research Grants Council (RGC) Joint Research Scheme )
Conflict of interest: no COI

Methods
RCT
Location : Multicenter / China
Follow-up duration (months): 1
CoronaVac booster (n = 40)
BNT162b2 booster (n = 40)
Inclusion criteria
  • Healthy adults
  • had received 2 doses of CoronaVac in previous cohort study
  • surrogate virus neutralization test results below 60% in their plasma specimens which were collected at one month after the second dose
Exclusion criteriaNR
Interventions
Intervention
2 IM doses of CoronaVac 28 days apart + 1 IM dose of BNT162b2 112 days later (mean)
Control
2 IM doses of CoronaVac 28 days apart + 1 IM dose of CoronaVac 116 days later (mean)
Participants
Randomized
80 participants
Characteristics of participants
Type of participants: Adults
N=80
28 males
Children: 0
Mean age:
Age range: NR
Description of participants
Adults that had received two doses of CoronaVac but had low immune response against SARS-CoV-2 at two centres in Hong Kong, China
Primary outcome
In the register
Spirometry [ Time Frame: 3 years ]FEV1 and FVC;Lung volume [ Time Frame: 3 years ]Litres;6 minute walk distance [ Time Frame: 3 years ] meters
In the report
Humoral immunogenicity measured by sVNT, PRNT and ELISA at one month after the third dose of vaccination
Documents
available

Protocol

NR

Statistical plan

*

Data-sharing stated: Unclear
Data accessibility: "All data produced in the present work are contained in the manuscript" (report) "Undecided" (trial registry) Corresponding authors: Malik Peiris, malik@hku.hk ; David S Hui, dschui@cuhk.edu.hk

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 This study was updated on June 16th, 2022 after a second publication of the trial report. In addition to the pre-print article, the study registry and pre-print article of preceding study were used in data extraction and risk of bias assessment. Most of the registry record is for the previous observational study and many details are missing for this RCT, including the outcomes. The study assessed immunogenicity and safety of a booster dose with either CoronaVac or BNT162b2 after two doses of CoronaVac. The target sample size specified in the registry was achieved. There is no change from the trial registration in the intervention and control groups. This trial was updated on Mars 9th, 2022 after the publication of the study report.This trial was updated again on June 17th, 2022 after a second publication of the study report.