Researchers at the University of Oxford in the UK are leading an international clinical trial to assess hydroxychloroquine for potentially preventing Covid-19 in frontline healthcare workers.

The double-blind, randomised, placebo-controlled trial has opened for participants at Oxford University Hospitals (OUH) in Oxford and Brighton on 21 May 2020.

Named COPCOV, the trial is led by the University of Oxford-supported Mahidol Oxford Tropical Medicine Research Unit (MORU) in Bangkok. It is designed to recruit 40,000 frontline healthcare workers and staff in Europe, Africa, Asia and South America.

COPCOV co-principal investigator Nicholas White said: “Covid-19 is a major risk for frontline healthcare workers around the world. We really do not know if chloroquine or hydroxychloroquine are beneficial or harmful against Covid-19.

“The best way to find out if they are effective in preventing Covid-19 is in a randomised clinical trial. That’s what COPCOV is, and why we’re doing this study.”

The Diabetes Trial Unit at the Churchill Hospital is managing the UK part of the study, which will be initially conducted at 25 sites across the country.

Following OUH and Brighton, four more sites are set to open by the end of this month, and a total of 25 by the end of next month.

Diabetes Trial Unit head Amanda Adler said: “We’ll be using the extensive experience we already have in running large international trials to run the COPCOV trial across the UK which will initially include 25 sites.

“So far, there is no drug or vaccine that has been shown to prevent Covid-19 vaccination, and we’ll be working closely with our MORU, Brighton, and Oxford University colleagues to find out if hydroxychloroquine can lower the risk of getting Covid-19 in UK health workers.”

Trial participants will be given hydroxychloroquine or placebo for three months. Results are expected to be available by the end of the year.

Earlier this week, researchers in Australia launched a clinical trial to assess hydroxychloroquine for the prevention of Covid-19 in healthcare workers who are at high risk.