Recruitment Target Reached | 招募人數達標

Thank you for your interest in participating. Our current recruitment target has been reached.


Randomised trial of COVID-19 booster vaccinations (Cobovax study) 

This is an open-label randomised clinical trial of COVID-19 vaccine booster in Hong Kong organised by the School of Public Health, the University of Hong Kong. Hong Kong citizens aged 18 or above who have already received two doses of BioNTech or Sinovac at least 6 months ago are invited to participate in this research study. We will randomly allocate each eligible participant to a third dose of mRNA vaccine (BioNTech) or inactivated vaccine (Sinovac), allowing us to compare the differences between mix-and-match versus same-technology third doses, for example in terms of enhancing immunity against COVID-19 or reactions after vaccination. Then, we will track these participants for a period of 1 year (2021 – 2022) to monitor the post-vaccination reactions and immune protection after receiving COVID-19 booster vaccination.

For details, please refer to our study website.


這是一項由香港大學公共衞生學院主辦,在香港本地進行的有關新冠病毒(COVID-19)疫苗加強劑的開放標籤隨機臨床試驗研究計劃,邀請香港18歲或以上、在6個月前已完成接種兩劑復必泰或科興疫苗的市民參加。本研究計劃會為合資格參與者隨機接種第三劑mRNA疫苗(復必泰)或滅活疫苗(科興),以比較接種混合類型疫苗對比接種同類型疫苗在如提升抵抗新冠肺炎免疫水平或接種疫苗後反應的差異。接著,我們將追踪參加者1年 (2021 – 2022),以全面監測接種新冠疫苗加強劑後的接種反應及免疫保護。