Actively Recruiting
Impact of COVID-19 Vaccines on Cerebrovascular Health - a Population-based Study
Led by Chinese University of Hong Kong · Updated on 2026-02-24
500
Participants Needed
1
Research Sites
26 weeks
Total Duration
On this page
AI-Summary
What this Trial Is About
Researchers are investigating how COVID-19 vaccines affect brain blood vessel health in a population-based study. The study focuses on citizens without neurological diseases from all socio-economic classes in Hong Kong. It aims to provide evidence-based information addressing concerns about strokes reported after vaccination, which have caused hesitancy despite efforts to increase vaccine uptake worldwide. Participants come from the CUHK Brain Health Longitudinal Study cohort and are divided into two groups: those who receive COVID-19 vaccines (SinoVac or BioNTech) and those who have not been vaccinated or infected with COVID-19. Both groups undergo baseline brain MRI and cognitive tests. The vaccinated group has follow-up MRI and assessments around 16 weeks after their second vaccine dose, while the control group matches this timing without vaccination. Participants provide demographic and health information and undergo laboratory tests, cognitive assessments, and brain imaging at baseline and follow-up. Face-to-face and phone visits occur to monitor clinical events and cognitive changes. The main outcomes measured are imaging markers and analysis to understand cerebrovascular changes. The study continues through December 2026, with ongoing monitoring every six months and cognitive testing annually after vaccination.
CONDITIONS
Brief Title
Impact of COVID-19 Vaccines on Cerebrovascular Health
Who Can Participate
Eligibility Criteria
You may qualify if you...
- Adults who are part of the CUHK Brain Health Longitudinal Study cohort
- Have received a baseline brain MRI scan
- Free of clinically evident neurological diseases at recruitment
- Able to provide informed consent to participate
You will not qualify if you...
- History of clinically evident stroke or dementia before joining the study
- Unable to give informed consent
- Have contraindications to MRI brain scans (e.g., non-MRI compatible implants, claustrophobia)
- Did not have a baseline brain MRI assessment
AI-Screening
AI-Powered Screening
Complete this quick 3-step screening to check your eligibility
Your Study Journey
Duration - 2 to 4 weeks
Participants are screened for eligibility to participate in the trial.
1 visit (in-person)
Duration - Baseline
Participants undergo baseline cognitive assessment, metabolic risk evaluation, and MRI brain scans to assess cerebrovascular health before vaccination or control matching.
1 visit (in-person)
Duration - 16 weeks (+/-4 weeks) after second vaccine dose and ongoing follow-up
Participants receive follow-up MRI brain scans, laboratory tests, cognitive assessments, and clinical evaluations timed approximately 16 weeks after the second dose of COVID-19 vaccine or matched timing for controls. Follow-up phone visits occur every 6 months, and cognitive assessments continue every 12 months thereafter.
1 visit (in-person) at 16 weeks plus phone visits every 6 months and cognitive assessments every 12 months
Trial Site Locations
Total: 1 location
1
Chinese University of Hong Kong
Hong Kong, Hong Kong
Actively Recruiting
Research Team
B
Bonaventure Yiu Ming IP, MB ChB
T
Thomas Wai Hong LEUNG, MB ChB
How is the study designed?
Study Type
OBSERVATIONAL
Masking
N/A
Allocation
N/A
Model
N/A
Primary Purpose
N/A
Number of Arms
2
Similar Trials
Frequently Asked Questions
Have more questions? Get in touch with our team for quick support
Not the Right Trial for You?
Explore thousands of other clinical trials that might be a better match.
Sign up to get personalized trial recommendations delivered to your inbox.
Already have an account? Log in here