A Study to Evaluate Vaccines Against COVID-19 in the Real World

Withdrawn

• Conditions: Hepatic Carcinoma; Chronic Liver Disease

• Registration Number: NCT04775056
• Lead Sponsor: Humanity & Health Medical Group Limited

Brief Summary

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and the resulting coronavirus disease 2019 (COVID-19) have afflicted tens of millions of people in a worldwide pandemic. Considering its high mortality and rapid spread, an effective vaccine is urgently needed to control this pandemic. Recently, mass vaccination campaigns using newly approved vaccines, ranging from conventional viral and protein-based vaccines to those that are more cutting edge, including DNA- and mRNA-based vaccines are beginning in many parts of the world. Randomized clinical trials of different vaccines reported efficacies for preventing COVID-19 in the range of 50% to 95%.

Although these randomized clinical trials are considered the "gold standard" for evaluating intervention effects, they have notable limitations of sample size and subgroup analysis, restrictive inclusion criteria, and a highly controlled setting that may not be replicated in a mass vaccine rollout.

The aim of this study is to evaluate the safety, tolerability, immunogenicity, and efficacy of different vaccines against COVID-19 under real-world practice conditions.

Detailed Description

Not available

Study Timeline

• Study First Submitted: 2021-02-26
• Study First Submitted QC: 2021-02-26
• Study First Posted: 2021-03-01
• Status Verified: 2022-08
• Study Start: 2022-08
• Last Update Submitted: 2022-08-01
• Last Update Posted: 2022-08-03
• Primary Completion: 2023-12
• Study Completion: 2023-12-31

Recruitment & Eligibility

• Status: WITHDRAWN
• Sex: All
• Target Recruitment: Not specified

Inclusion Criteria

• Subjects received COVID-19 vaccines;
• Able to comprehend and provide written informed consent in accordance with institutional guidelines.

Exclusion Criteria

• Not received any COVID-19 vaccines;
• Not willing to participate and/or give their written informed consent.

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
Immunogenicity index-seroconversion rates of neutralizing antibody	The 4 weeks after the second dose vaccination	Neutralizing antibody assay will be performed using the micro-neutralization method. Seroconversion will be defined as a change from seronegative (\<1:8) to seropositive (≥1:8), or ≥4 fold increase from baseline.

Secondary Outcome Measures

Name	Time	Method
Safety index-incidence of adverse reactions	Day 0-28 after each dose vaccination	Incidence of adverse reactions after each dose vaccination
Immunogenicity index-seropositive rates of neutralizing antibody	The 4, 12, 24, and 48 weeks after the second dose vaccination	neutralizing antibody assay will be performed using the micro-neutralization method, and subjects with a antibody titer ≥1:8 will defined as seropositive.

Trial Locations

Locations (1)

Humanity & Health Medical Group; 🇭🇰 Hong Kong, Hong Kong